xref: /aosp_15_r20/external/llvm/utils/TableGen/FixedLenDecoderEmitter.cpp (revision 9880d6810fe72a1726cb53787c6711e909410d58)
1*9880d681SAndroid Build Coastguard Worker //===------------ FixedLenDecoderEmitter.cpp - Decoder Generator ----------===//
2*9880d681SAndroid Build Coastguard Worker //
3*9880d681SAndroid Build Coastguard Worker //                     The LLVM Compiler Infrastructure
4*9880d681SAndroid Build Coastguard Worker //
5*9880d681SAndroid Build Coastguard Worker // This file is distributed under the University of Illinois Open Source
6*9880d681SAndroid Build Coastguard Worker // License. See LICENSE.TXT for details.
7*9880d681SAndroid Build Coastguard Worker //
8*9880d681SAndroid Build Coastguard Worker //===----------------------------------------------------------------------===//
9*9880d681SAndroid Build Coastguard Worker //
10*9880d681SAndroid Build Coastguard Worker // It contains the tablegen backend that emits the decoder functions for
11*9880d681SAndroid Build Coastguard Worker // targets with fixed length instruction set.
12*9880d681SAndroid Build Coastguard Worker //
13*9880d681SAndroid Build Coastguard Worker //===----------------------------------------------------------------------===//
14*9880d681SAndroid Build Coastguard Worker 
15*9880d681SAndroid Build Coastguard Worker #include "CodeGenTarget.h"
16*9880d681SAndroid Build Coastguard Worker #include "llvm/ADT/APInt.h"
17*9880d681SAndroid Build Coastguard Worker #include "llvm/ADT/SmallString.h"
18*9880d681SAndroid Build Coastguard Worker #include "llvm/ADT/StringExtras.h"
19*9880d681SAndroid Build Coastguard Worker #include "llvm/ADT/StringRef.h"
20*9880d681SAndroid Build Coastguard Worker #include "llvm/ADT/Twine.h"
21*9880d681SAndroid Build Coastguard Worker #include "llvm/MC/MCFixedLenDisassembler.h"
22*9880d681SAndroid Build Coastguard Worker #include "llvm/Support/DataTypes.h"
23*9880d681SAndroid Build Coastguard Worker #include "llvm/Support/Debug.h"
24*9880d681SAndroid Build Coastguard Worker #include "llvm/Support/FormattedStream.h"
25*9880d681SAndroid Build Coastguard Worker #include "llvm/Support/LEB128.h"
26*9880d681SAndroid Build Coastguard Worker #include "llvm/Support/raw_ostream.h"
27*9880d681SAndroid Build Coastguard Worker #include "llvm/TableGen/Error.h"
28*9880d681SAndroid Build Coastguard Worker #include "llvm/TableGen/Record.h"
29*9880d681SAndroid Build Coastguard Worker #include <map>
30*9880d681SAndroid Build Coastguard Worker #include <string>
31*9880d681SAndroid Build Coastguard Worker #include <utility>
32*9880d681SAndroid Build Coastguard Worker #include <vector>
33*9880d681SAndroid Build Coastguard Worker 
34*9880d681SAndroid Build Coastguard Worker using namespace llvm;
35*9880d681SAndroid Build Coastguard Worker 
36*9880d681SAndroid Build Coastguard Worker #define DEBUG_TYPE "decoder-emitter"
37*9880d681SAndroid Build Coastguard Worker 
38*9880d681SAndroid Build Coastguard Worker namespace {
39*9880d681SAndroid Build Coastguard Worker struct EncodingField {
40*9880d681SAndroid Build Coastguard Worker   unsigned Base, Width, Offset;
EncodingField__anon6e3390920111::EncodingField41*9880d681SAndroid Build Coastguard Worker   EncodingField(unsigned B, unsigned W, unsigned O)
42*9880d681SAndroid Build Coastguard Worker     : Base(B), Width(W), Offset(O) { }
43*9880d681SAndroid Build Coastguard Worker };
44*9880d681SAndroid Build Coastguard Worker 
45*9880d681SAndroid Build Coastguard Worker struct OperandInfo {
46*9880d681SAndroid Build Coastguard Worker   std::vector<EncodingField> Fields;
47*9880d681SAndroid Build Coastguard Worker   std::string Decoder;
48*9880d681SAndroid Build Coastguard Worker   bool HasCompleteDecoder;
49*9880d681SAndroid Build Coastguard Worker 
OperandInfo__anon6e3390920111::OperandInfo50*9880d681SAndroid Build Coastguard Worker   OperandInfo(std::string D, bool HCD)
51*9880d681SAndroid Build Coastguard Worker       : Decoder(std::move(D)), HasCompleteDecoder(HCD) {}
52*9880d681SAndroid Build Coastguard Worker 
addField__anon6e3390920111::OperandInfo53*9880d681SAndroid Build Coastguard Worker   void addField(unsigned Base, unsigned Width, unsigned Offset) {
54*9880d681SAndroid Build Coastguard Worker     Fields.push_back(EncodingField(Base, Width, Offset));
55*9880d681SAndroid Build Coastguard Worker   }
56*9880d681SAndroid Build Coastguard Worker 
numFields__anon6e3390920111::OperandInfo57*9880d681SAndroid Build Coastguard Worker   unsigned numFields() const { return Fields.size(); }
58*9880d681SAndroid Build Coastguard Worker 
59*9880d681SAndroid Build Coastguard Worker   typedef std::vector<EncodingField>::const_iterator const_iterator;
60*9880d681SAndroid Build Coastguard Worker 
begin__anon6e3390920111::OperandInfo61*9880d681SAndroid Build Coastguard Worker   const_iterator begin() const { return Fields.begin(); }
end__anon6e3390920111::OperandInfo62*9880d681SAndroid Build Coastguard Worker   const_iterator end() const   { return Fields.end();   }
63*9880d681SAndroid Build Coastguard Worker };
64*9880d681SAndroid Build Coastguard Worker 
65*9880d681SAndroid Build Coastguard Worker typedef std::vector<uint8_t> DecoderTable;
66*9880d681SAndroid Build Coastguard Worker typedef uint32_t DecoderFixup;
67*9880d681SAndroid Build Coastguard Worker typedef std::vector<DecoderFixup> FixupList;
68*9880d681SAndroid Build Coastguard Worker typedef std::vector<FixupList> FixupScopeList;
69*9880d681SAndroid Build Coastguard Worker typedef SmallSetVector<std::string, 16> PredicateSet;
70*9880d681SAndroid Build Coastguard Worker typedef SmallSetVector<std::string, 16> DecoderSet;
71*9880d681SAndroid Build Coastguard Worker struct DecoderTableInfo {
72*9880d681SAndroid Build Coastguard Worker   DecoderTable Table;
73*9880d681SAndroid Build Coastguard Worker   FixupScopeList FixupStack;
74*9880d681SAndroid Build Coastguard Worker   PredicateSet Predicates;
75*9880d681SAndroid Build Coastguard Worker   DecoderSet Decoders;
76*9880d681SAndroid Build Coastguard Worker };
77*9880d681SAndroid Build Coastguard Worker 
78*9880d681SAndroid Build Coastguard Worker } // End anonymous namespace
79*9880d681SAndroid Build Coastguard Worker 
80*9880d681SAndroid Build Coastguard Worker namespace {
81*9880d681SAndroid Build Coastguard Worker class FixedLenDecoderEmitter {
82*9880d681SAndroid Build Coastguard Worker   ArrayRef<const CodeGenInstruction *> NumberedInstructions;
83*9880d681SAndroid Build Coastguard Worker public:
84*9880d681SAndroid Build Coastguard Worker 
85*9880d681SAndroid Build Coastguard Worker   // Defaults preserved here for documentation, even though they aren't
86*9880d681SAndroid Build Coastguard Worker   // strictly necessary given the way that this is currently being called.
FixedLenDecoderEmitter(RecordKeeper & R,std::string PredicateNamespace,std::string GPrefix="if (",std::string GPostfix=" == MCDisassembler::Fail)",std::string ROK="MCDisassembler::Success",std::string RFail="MCDisassembler::Fail",std::string L="")87*9880d681SAndroid Build Coastguard Worker   FixedLenDecoderEmitter(RecordKeeper &R, std::string PredicateNamespace,
88*9880d681SAndroid Build Coastguard Worker                          std::string GPrefix = "if (",
89*9880d681SAndroid Build Coastguard Worker                          std::string GPostfix = " == MCDisassembler::Fail)",
90*9880d681SAndroid Build Coastguard Worker                          std::string ROK = "MCDisassembler::Success",
91*9880d681SAndroid Build Coastguard Worker                          std::string RFail = "MCDisassembler::Fail",
92*9880d681SAndroid Build Coastguard Worker                          std::string L = "")
93*9880d681SAndroid Build Coastguard Worker       : Target(R), PredicateNamespace(std::move(PredicateNamespace)),
94*9880d681SAndroid Build Coastguard Worker         GuardPrefix(std::move(GPrefix)), GuardPostfix(std::move(GPostfix)),
95*9880d681SAndroid Build Coastguard Worker         ReturnOK(std::move(ROK)), ReturnFail(std::move(RFail)),
96*9880d681SAndroid Build Coastguard Worker         Locals(std::move(L)) {}
97*9880d681SAndroid Build Coastguard Worker 
98*9880d681SAndroid Build Coastguard Worker   // Emit the decoder state machine table.
99*9880d681SAndroid Build Coastguard Worker   void emitTable(formatted_raw_ostream &o, DecoderTable &Table,
100*9880d681SAndroid Build Coastguard Worker                  unsigned Indentation, unsigned BitWidth,
101*9880d681SAndroid Build Coastguard Worker                  StringRef Namespace) const;
102*9880d681SAndroid Build Coastguard Worker   void emitPredicateFunction(formatted_raw_ostream &OS,
103*9880d681SAndroid Build Coastguard Worker                              PredicateSet &Predicates,
104*9880d681SAndroid Build Coastguard Worker                              unsigned Indentation) const;
105*9880d681SAndroid Build Coastguard Worker   void emitDecoderFunction(formatted_raw_ostream &OS,
106*9880d681SAndroid Build Coastguard Worker                            DecoderSet &Decoders,
107*9880d681SAndroid Build Coastguard Worker                            unsigned Indentation) const;
108*9880d681SAndroid Build Coastguard Worker 
109*9880d681SAndroid Build Coastguard Worker   // run - Output the code emitter
110*9880d681SAndroid Build Coastguard Worker   void run(raw_ostream &o);
111*9880d681SAndroid Build Coastguard Worker 
112*9880d681SAndroid Build Coastguard Worker private:
113*9880d681SAndroid Build Coastguard Worker   CodeGenTarget Target;
114*9880d681SAndroid Build Coastguard Worker public:
115*9880d681SAndroid Build Coastguard Worker   std::string PredicateNamespace;
116*9880d681SAndroid Build Coastguard Worker   std::string GuardPrefix, GuardPostfix;
117*9880d681SAndroid Build Coastguard Worker   std::string ReturnOK, ReturnFail;
118*9880d681SAndroid Build Coastguard Worker   std::string Locals;
119*9880d681SAndroid Build Coastguard Worker };
120*9880d681SAndroid Build Coastguard Worker } // End anonymous namespace
121*9880d681SAndroid Build Coastguard Worker 
122*9880d681SAndroid Build Coastguard Worker // The set (BIT_TRUE, BIT_FALSE, BIT_UNSET) represents a ternary logic system
123*9880d681SAndroid Build Coastguard Worker // for a bit value.
124*9880d681SAndroid Build Coastguard Worker //
125*9880d681SAndroid Build Coastguard Worker // BIT_UNFILTERED is used as the init value for a filter position.  It is used
126*9880d681SAndroid Build Coastguard Worker // only for filter processings.
127*9880d681SAndroid Build Coastguard Worker typedef enum {
128*9880d681SAndroid Build Coastguard Worker   BIT_TRUE,      // '1'
129*9880d681SAndroid Build Coastguard Worker   BIT_FALSE,     // '0'
130*9880d681SAndroid Build Coastguard Worker   BIT_UNSET,     // '?'
131*9880d681SAndroid Build Coastguard Worker   BIT_UNFILTERED // unfiltered
132*9880d681SAndroid Build Coastguard Worker } bit_value_t;
133*9880d681SAndroid Build Coastguard Worker 
ValueSet(bit_value_t V)134*9880d681SAndroid Build Coastguard Worker static bool ValueSet(bit_value_t V) {
135*9880d681SAndroid Build Coastguard Worker   return (V == BIT_TRUE || V == BIT_FALSE);
136*9880d681SAndroid Build Coastguard Worker }
ValueNotSet(bit_value_t V)137*9880d681SAndroid Build Coastguard Worker static bool ValueNotSet(bit_value_t V) {
138*9880d681SAndroid Build Coastguard Worker   return (V == BIT_UNSET);
139*9880d681SAndroid Build Coastguard Worker }
Value(bit_value_t V)140*9880d681SAndroid Build Coastguard Worker static int Value(bit_value_t V) {
141*9880d681SAndroid Build Coastguard Worker   return ValueNotSet(V) ? -1 : (V == BIT_FALSE ? 0 : 1);
142*9880d681SAndroid Build Coastguard Worker }
bitFromBits(const BitsInit & bits,unsigned index)143*9880d681SAndroid Build Coastguard Worker static bit_value_t bitFromBits(const BitsInit &bits, unsigned index) {
144*9880d681SAndroid Build Coastguard Worker   if (BitInit *bit = dyn_cast<BitInit>(bits.getBit(index)))
145*9880d681SAndroid Build Coastguard Worker     return bit->getValue() ? BIT_TRUE : BIT_FALSE;
146*9880d681SAndroid Build Coastguard Worker 
147*9880d681SAndroid Build Coastguard Worker   // The bit is uninitialized.
148*9880d681SAndroid Build Coastguard Worker   return BIT_UNSET;
149*9880d681SAndroid Build Coastguard Worker }
150*9880d681SAndroid Build Coastguard Worker // Prints the bit value for each position.
dumpBits(raw_ostream & o,const BitsInit & bits)151*9880d681SAndroid Build Coastguard Worker static void dumpBits(raw_ostream &o, const BitsInit &bits) {
152*9880d681SAndroid Build Coastguard Worker   for (unsigned index = bits.getNumBits(); index > 0; --index) {
153*9880d681SAndroid Build Coastguard Worker     switch (bitFromBits(bits, index - 1)) {
154*9880d681SAndroid Build Coastguard Worker     case BIT_TRUE:
155*9880d681SAndroid Build Coastguard Worker       o << "1";
156*9880d681SAndroid Build Coastguard Worker       break;
157*9880d681SAndroid Build Coastguard Worker     case BIT_FALSE:
158*9880d681SAndroid Build Coastguard Worker       o << "0";
159*9880d681SAndroid Build Coastguard Worker       break;
160*9880d681SAndroid Build Coastguard Worker     case BIT_UNSET:
161*9880d681SAndroid Build Coastguard Worker       o << "_";
162*9880d681SAndroid Build Coastguard Worker       break;
163*9880d681SAndroid Build Coastguard Worker     default:
164*9880d681SAndroid Build Coastguard Worker       llvm_unreachable("unexpected return value from bitFromBits");
165*9880d681SAndroid Build Coastguard Worker     }
166*9880d681SAndroid Build Coastguard Worker   }
167*9880d681SAndroid Build Coastguard Worker }
168*9880d681SAndroid Build Coastguard Worker 
getBitsField(const Record & def,const char * str)169*9880d681SAndroid Build Coastguard Worker static BitsInit &getBitsField(const Record &def, const char *str) {
170*9880d681SAndroid Build Coastguard Worker   BitsInit *bits = def.getValueAsBitsInit(str);
171*9880d681SAndroid Build Coastguard Worker   return *bits;
172*9880d681SAndroid Build Coastguard Worker }
173*9880d681SAndroid Build Coastguard Worker 
174*9880d681SAndroid Build Coastguard Worker // Forward declaration.
175*9880d681SAndroid Build Coastguard Worker namespace {
176*9880d681SAndroid Build Coastguard Worker class FilterChooser;
177*9880d681SAndroid Build Coastguard Worker } // End anonymous namespace
178*9880d681SAndroid Build Coastguard Worker 
179*9880d681SAndroid Build Coastguard Worker // Representation of the instruction to work on.
180*9880d681SAndroid Build Coastguard Worker typedef std::vector<bit_value_t> insn_t;
181*9880d681SAndroid Build Coastguard Worker 
182*9880d681SAndroid Build Coastguard Worker /// Filter - Filter works with FilterChooser to produce the decoding tree for
183*9880d681SAndroid Build Coastguard Worker /// the ISA.
184*9880d681SAndroid Build Coastguard Worker ///
185*9880d681SAndroid Build Coastguard Worker /// It is useful to think of a Filter as governing the switch stmts of the
186*9880d681SAndroid Build Coastguard Worker /// decoding tree in a certain level.  Each case stmt delegates to an inferior
187*9880d681SAndroid Build Coastguard Worker /// FilterChooser to decide what further decoding logic to employ, or in another
188*9880d681SAndroid Build Coastguard Worker /// words, what other remaining bits to look at.  The FilterChooser eventually
189*9880d681SAndroid Build Coastguard Worker /// chooses a best Filter to do its job.
190*9880d681SAndroid Build Coastguard Worker ///
191*9880d681SAndroid Build Coastguard Worker /// This recursive scheme ends when the number of Opcodes assigned to the
192*9880d681SAndroid Build Coastguard Worker /// FilterChooser becomes 1 or if there is a conflict.  A conflict happens when
193*9880d681SAndroid Build Coastguard Worker /// the Filter/FilterChooser combo does not know how to distinguish among the
194*9880d681SAndroid Build Coastguard Worker /// Opcodes assigned.
195*9880d681SAndroid Build Coastguard Worker ///
196*9880d681SAndroid Build Coastguard Worker /// An example of a conflict is
197*9880d681SAndroid Build Coastguard Worker ///
198*9880d681SAndroid Build Coastguard Worker /// Conflict:
199*9880d681SAndroid Build Coastguard Worker ///                     111101000.00........00010000....
200*9880d681SAndroid Build Coastguard Worker ///                     111101000.00........0001........
201*9880d681SAndroid Build Coastguard Worker ///                     1111010...00........0001........
202*9880d681SAndroid Build Coastguard Worker ///                     1111010...00....................
203*9880d681SAndroid Build Coastguard Worker ///                     1111010.........................
204*9880d681SAndroid Build Coastguard Worker ///                     1111............................
205*9880d681SAndroid Build Coastguard Worker ///                     ................................
206*9880d681SAndroid Build Coastguard Worker ///     VST4q8a         111101000_00________00010000____
207*9880d681SAndroid Build Coastguard Worker ///     VST4q8b         111101000_00________00010000____
208*9880d681SAndroid Build Coastguard Worker ///
209*9880d681SAndroid Build Coastguard Worker /// The Debug output shows the path that the decoding tree follows to reach the
210*9880d681SAndroid Build Coastguard Worker /// the conclusion that there is a conflict.  VST4q8a is a vst4 to double-spaced
211*9880d681SAndroid Build Coastguard Worker /// even registers, while VST4q8b is a vst4 to double-spaced odd registers.
212*9880d681SAndroid Build Coastguard Worker ///
213*9880d681SAndroid Build Coastguard Worker /// The encoding info in the .td files does not specify this meta information,
214*9880d681SAndroid Build Coastguard Worker /// which could have been used by the decoder to resolve the conflict.  The
215*9880d681SAndroid Build Coastguard Worker /// decoder could try to decode the even/odd register numbering and assign to
216*9880d681SAndroid Build Coastguard Worker /// VST4q8a or VST4q8b, but for the time being, the decoder chooses the "a"
217*9880d681SAndroid Build Coastguard Worker /// version and return the Opcode since the two have the same Asm format string.
218*9880d681SAndroid Build Coastguard Worker namespace {
219*9880d681SAndroid Build Coastguard Worker class Filter {
220*9880d681SAndroid Build Coastguard Worker protected:
221*9880d681SAndroid Build Coastguard Worker   const FilterChooser *Owner;// points to the FilterChooser who owns this filter
222*9880d681SAndroid Build Coastguard Worker   unsigned StartBit; // the starting bit position
223*9880d681SAndroid Build Coastguard Worker   unsigned NumBits; // number of bits to filter
224*9880d681SAndroid Build Coastguard Worker   bool Mixed; // a mixed region contains both set and unset bits
225*9880d681SAndroid Build Coastguard Worker 
226*9880d681SAndroid Build Coastguard Worker   // Map of well-known segment value to the set of uid's with that value.
227*9880d681SAndroid Build Coastguard Worker   std::map<uint64_t, std::vector<unsigned> > FilteredInstructions;
228*9880d681SAndroid Build Coastguard Worker 
229*9880d681SAndroid Build Coastguard Worker   // Set of uid's with non-constant segment values.
230*9880d681SAndroid Build Coastguard Worker   std::vector<unsigned> VariableInstructions;
231*9880d681SAndroid Build Coastguard Worker 
232*9880d681SAndroid Build Coastguard Worker   // Map of well-known segment value to its delegate.
233*9880d681SAndroid Build Coastguard Worker   std::map<unsigned, std::unique_ptr<const FilterChooser>> FilterChooserMap;
234*9880d681SAndroid Build Coastguard Worker 
235*9880d681SAndroid Build Coastguard Worker   // Number of instructions which fall under FilteredInstructions category.
236*9880d681SAndroid Build Coastguard Worker   unsigned NumFiltered;
237*9880d681SAndroid Build Coastguard Worker 
238*9880d681SAndroid Build Coastguard Worker   // Keeps track of the last opcode in the filtered bucket.
239*9880d681SAndroid Build Coastguard Worker   unsigned LastOpcFiltered;
240*9880d681SAndroid Build Coastguard Worker 
241*9880d681SAndroid Build Coastguard Worker public:
getNumFiltered() const242*9880d681SAndroid Build Coastguard Worker   unsigned getNumFiltered() const { return NumFiltered; }
getSingletonOpc() const243*9880d681SAndroid Build Coastguard Worker   unsigned getSingletonOpc() const {
244*9880d681SAndroid Build Coastguard Worker     assert(NumFiltered == 1);
245*9880d681SAndroid Build Coastguard Worker     return LastOpcFiltered;
246*9880d681SAndroid Build Coastguard Worker   }
247*9880d681SAndroid Build Coastguard Worker   // Return the filter chooser for the group of instructions without constant
248*9880d681SAndroid Build Coastguard Worker   // segment values.
getVariableFC() const249*9880d681SAndroid Build Coastguard Worker   const FilterChooser &getVariableFC() const {
250*9880d681SAndroid Build Coastguard Worker     assert(NumFiltered == 1);
251*9880d681SAndroid Build Coastguard Worker     assert(FilterChooserMap.size() == 1);
252*9880d681SAndroid Build Coastguard Worker     return *(FilterChooserMap.find((unsigned)-1)->second);
253*9880d681SAndroid Build Coastguard Worker   }
254*9880d681SAndroid Build Coastguard Worker 
255*9880d681SAndroid Build Coastguard Worker   Filter(Filter &&f);
256*9880d681SAndroid Build Coastguard Worker   Filter(FilterChooser &owner, unsigned startBit, unsigned numBits, bool mixed);
257*9880d681SAndroid Build Coastguard Worker 
258*9880d681SAndroid Build Coastguard Worker   ~Filter();
259*9880d681SAndroid Build Coastguard Worker 
260*9880d681SAndroid Build Coastguard Worker   // Divides the decoding task into sub tasks and delegates them to the
261*9880d681SAndroid Build Coastguard Worker   // inferior FilterChooser's.
262*9880d681SAndroid Build Coastguard Worker   //
263*9880d681SAndroid Build Coastguard Worker   // A special case arises when there's only one entry in the filtered
264*9880d681SAndroid Build Coastguard Worker   // instructions.  In order to unambiguously decode the singleton, we need to
265*9880d681SAndroid Build Coastguard Worker   // match the remaining undecoded encoding bits against the singleton.
266*9880d681SAndroid Build Coastguard Worker   void recurse();
267*9880d681SAndroid Build Coastguard Worker 
268*9880d681SAndroid Build Coastguard Worker   // Emit table entries to decode instructions given a segment or segments of
269*9880d681SAndroid Build Coastguard Worker   // bits.
270*9880d681SAndroid Build Coastguard Worker   void emitTableEntry(DecoderTableInfo &TableInfo) const;
271*9880d681SAndroid Build Coastguard Worker 
272*9880d681SAndroid Build Coastguard Worker   // Returns the number of fanout produced by the filter.  More fanout implies
273*9880d681SAndroid Build Coastguard Worker   // the filter distinguishes more categories of instructions.
274*9880d681SAndroid Build Coastguard Worker   unsigned usefulness() const;
275*9880d681SAndroid Build Coastguard Worker }; // End of class Filter
276*9880d681SAndroid Build Coastguard Worker } // End anonymous namespace
277*9880d681SAndroid Build Coastguard Worker 
278*9880d681SAndroid Build Coastguard Worker // These are states of our finite state machines used in FilterChooser's
279*9880d681SAndroid Build Coastguard Worker // filterProcessor() which produces the filter candidates to use.
280*9880d681SAndroid Build Coastguard Worker typedef enum {
281*9880d681SAndroid Build Coastguard Worker   ATTR_NONE,
282*9880d681SAndroid Build Coastguard Worker   ATTR_FILTERED,
283*9880d681SAndroid Build Coastguard Worker   ATTR_ALL_SET,
284*9880d681SAndroid Build Coastguard Worker   ATTR_ALL_UNSET,
285*9880d681SAndroid Build Coastguard Worker   ATTR_MIXED
286*9880d681SAndroid Build Coastguard Worker } bitAttr_t;
287*9880d681SAndroid Build Coastguard Worker 
288*9880d681SAndroid Build Coastguard Worker /// FilterChooser - FilterChooser chooses the best filter among a set of Filters
289*9880d681SAndroid Build Coastguard Worker /// in order to perform the decoding of instructions at the current level.
290*9880d681SAndroid Build Coastguard Worker ///
291*9880d681SAndroid Build Coastguard Worker /// Decoding proceeds from the top down.  Based on the well-known encoding bits
292*9880d681SAndroid Build Coastguard Worker /// of instructions available, FilterChooser builds up the possible Filters that
293*9880d681SAndroid Build Coastguard Worker /// can further the task of decoding by distinguishing among the remaining
294*9880d681SAndroid Build Coastguard Worker /// candidate instructions.
295*9880d681SAndroid Build Coastguard Worker ///
296*9880d681SAndroid Build Coastguard Worker /// Once a filter has been chosen, it is called upon to divide the decoding task
297*9880d681SAndroid Build Coastguard Worker /// into sub-tasks and delegates them to its inferior FilterChoosers for further
298*9880d681SAndroid Build Coastguard Worker /// processings.
299*9880d681SAndroid Build Coastguard Worker ///
300*9880d681SAndroid Build Coastguard Worker /// It is useful to think of a Filter as governing the switch stmts of the
301*9880d681SAndroid Build Coastguard Worker /// decoding tree.  And each case is delegated to an inferior FilterChooser to
302*9880d681SAndroid Build Coastguard Worker /// decide what further remaining bits to look at.
303*9880d681SAndroid Build Coastguard Worker namespace {
304*9880d681SAndroid Build Coastguard Worker class FilterChooser {
305*9880d681SAndroid Build Coastguard Worker protected:
306*9880d681SAndroid Build Coastguard Worker   friend class Filter;
307*9880d681SAndroid Build Coastguard Worker 
308*9880d681SAndroid Build Coastguard Worker   // Vector of codegen instructions to choose our filter.
309*9880d681SAndroid Build Coastguard Worker   ArrayRef<const CodeGenInstruction *> AllInstructions;
310*9880d681SAndroid Build Coastguard Worker 
311*9880d681SAndroid Build Coastguard Worker   // Vector of uid's for this filter chooser to work on.
312*9880d681SAndroid Build Coastguard Worker   const std::vector<unsigned> &Opcodes;
313*9880d681SAndroid Build Coastguard Worker 
314*9880d681SAndroid Build Coastguard Worker   // Lookup table for the operand decoding of instructions.
315*9880d681SAndroid Build Coastguard Worker   const std::map<unsigned, std::vector<OperandInfo> > &Operands;
316*9880d681SAndroid Build Coastguard Worker 
317*9880d681SAndroid Build Coastguard Worker   // Vector of candidate filters.
318*9880d681SAndroid Build Coastguard Worker   std::vector<Filter> Filters;
319*9880d681SAndroid Build Coastguard Worker 
320*9880d681SAndroid Build Coastguard Worker   // Array of bit values passed down from our parent.
321*9880d681SAndroid Build Coastguard Worker   // Set to all BIT_UNFILTERED's for Parent == NULL.
322*9880d681SAndroid Build Coastguard Worker   std::vector<bit_value_t> FilterBitValues;
323*9880d681SAndroid Build Coastguard Worker 
324*9880d681SAndroid Build Coastguard Worker   // Links to the FilterChooser above us in the decoding tree.
325*9880d681SAndroid Build Coastguard Worker   const FilterChooser *Parent;
326*9880d681SAndroid Build Coastguard Worker 
327*9880d681SAndroid Build Coastguard Worker   // Index of the best filter from Filters.
328*9880d681SAndroid Build Coastguard Worker   int BestIndex;
329*9880d681SAndroid Build Coastguard Worker 
330*9880d681SAndroid Build Coastguard Worker   // Width of instructions
331*9880d681SAndroid Build Coastguard Worker   unsigned BitWidth;
332*9880d681SAndroid Build Coastguard Worker 
333*9880d681SAndroid Build Coastguard Worker   // Parent emitter
334*9880d681SAndroid Build Coastguard Worker   const FixedLenDecoderEmitter *Emitter;
335*9880d681SAndroid Build Coastguard Worker 
336*9880d681SAndroid Build Coastguard Worker   FilterChooser(const FilterChooser &) = delete;
337*9880d681SAndroid Build Coastguard Worker   void operator=(const FilterChooser &) = delete;
338*9880d681SAndroid Build Coastguard Worker public:
339*9880d681SAndroid Build Coastguard Worker 
FilterChooser(ArrayRef<const CodeGenInstruction * > Insts,const std::vector<unsigned> & IDs,const std::map<unsigned,std::vector<OperandInfo>> & Ops,unsigned BW,const FixedLenDecoderEmitter * E)340*9880d681SAndroid Build Coastguard Worker   FilterChooser(ArrayRef<const CodeGenInstruction *> Insts,
341*9880d681SAndroid Build Coastguard Worker                 const std::vector<unsigned> &IDs,
342*9880d681SAndroid Build Coastguard Worker                 const std::map<unsigned, std::vector<OperandInfo> > &Ops,
343*9880d681SAndroid Build Coastguard Worker                 unsigned BW,
344*9880d681SAndroid Build Coastguard Worker                 const FixedLenDecoderEmitter *E)
345*9880d681SAndroid Build Coastguard Worker     : AllInstructions(Insts), Opcodes(IDs), Operands(Ops), Filters(),
346*9880d681SAndroid Build Coastguard Worker       FilterBitValues(BW, BIT_UNFILTERED), Parent(nullptr), BestIndex(-1),
347*9880d681SAndroid Build Coastguard Worker       BitWidth(BW), Emitter(E) {
348*9880d681SAndroid Build Coastguard Worker     doFilter();
349*9880d681SAndroid Build Coastguard Worker   }
350*9880d681SAndroid Build Coastguard Worker 
FilterChooser(ArrayRef<const CodeGenInstruction * > Insts,const std::vector<unsigned> & IDs,const std::map<unsigned,std::vector<OperandInfo>> & Ops,const std::vector<bit_value_t> & ParentFilterBitValues,const FilterChooser & parent)351*9880d681SAndroid Build Coastguard Worker   FilterChooser(ArrayRef<const CodeGenInstruction *> Insts,
352*9880d681SAndroid Build Coastguard Worker                 const std::vector<unsigned> &IDs,
353*9880d681SAndroid Build Coastguard Worker                 const std::map<unsigned, std::vector<OperandInfo> > &Ops,
354*9880d681SAndroid Build Coastguard Worker                 const std::vector<bit_value_t> &ParentFilterBitValues,
355*9880d681SAndroid Build Coastguard Worker                 const FilterChooser &parent)
356*9880d681SAndroid Build Coastguard Worker     : AllInstructions(Insts), Opcodes(IDs), Operands(Ops),
357*9880d681SAndroid Build Coastguard Worker       Filters(), FilterBitValues(ParentFilterBitValues),
358*9880d681SAndroid Build Coastguard Worker       Parent(&parent), BestIndex(-1), BitWidth(parent.BitWidth),
359*9880d681SAndroid Build Coastguard Worker       Emitter(parent.Emitter) {
360*9880d681SAndroid Build Coastguard Worker     doFilter();
361*9880d681SAndroid Build Coastguard Worker   }
362*9880d681SAndroid Build Coastguard Worker 
getBitWidth() const363*9880d681SAndroid Build Coastguard Worker   unsigned getBitWidth() const { return BitWidth; }
364*9880d681SAndroid Build Coastguard Worker 
365*9880d681SAndroid Build Coastguard Worker protected:
366*9880d681SAndroid Build Coastguard Worker   // Populates the insn given the uid.
insnWithID(insn_t & Insn,unsigned Opcode) const367*9880d681SAndroid Build Coastguard Worker   void insnWithID(insn_t &Insn, unsigned Opcode) const {
368*9880d681SAndroid Build Coastguard Worker     BitsInit &Bits = getBitsField(*AllInstructions[Opcode]->TheDef, "Inst");
369*9880d681SAndroid Build Coastguard Worker 
370*9880d681SAndroid Build Coastguard Worker     // We may have a SoftFail bitmask, which specifies a mask where an encoding
371*9880d681SAndroid Build Coastguard Worker     // may differ from the value in "Inst" and yet still be valid, but the
372*9880d681SAndroid Build Coastguard Worker     // disassembler should return SoftFail instead of Success.
373*9880d681SAndroid Build Coastguard Worker     //
374*9880d681SAndroid Build Coastguard Worker     // This is used for marking UNPREDICTABLE instructions in the ARM world.
375*9880d681SAndroid Build Coastguard Worker     BitsInit *SFBits =
376*9880d681SAndroid Build Coastguard Worker       AllInstructions[Opcode]->TheDef->getValueAsBitsInit("SoftFail");
377*9880d681SAndroid Build Coastguard Worker 
378*9880d681SAndroid Build Coastguard Worker     for (unsigned i = 0; i < BitWidth; ++i) {
379*9880d681SAndroid Build Coastguard Worker       if (SFBits && bitFromBits(*SFBits, i) == BIT_TRUE)
380*9880d681SAndroid Build Coastguard Worker         Insn.push_back(BIT_UNSET);
381*9880d681SAndroid Build Coastguard Worker       else
382*9880d681SAndroid Build Coastguard Worker         Insn.push_back(bitFromBits(Bits, i));
383*9880d681SAndroid Build Coastguard Worker     }
384*9880d681SAndroid Build Coastguard Worker   }
385*9880d681SAndroid Build Coastguard Worker 
386*9880d681SAndroid Build Coastguard Worker   // Returns the record name.
nameWithID(unsigned Opcode) const387*9880d681SAndroid Build Coastguard Worker   const std::string &nameWithID(unsigned Opcode) const {
388*9880d681SAndroid Build Coastguard Worker     return AllInstructions[Opcode]->TheDef->getName();
389*9880d681SAndroid Build Coastguard Worker   }
390*9880d681SAndroid Build Coastguard Worker 
391*9880d681SAndroid Build Coastguard Worker   // Populates the field of the insn given the start position and the number of
392*9880d681SAndroid Build Coastguard Worker   // consecutive bits to scan for.
393*9880d681SAndroid Build Coastguard Worker   //
394*9880d681SAndroid Build Coastguard Worker   // Returns false if there exists any uninitialized bit value in the range.
395*9880d681SAndroid Build Coastguard Worker   // Returns true, otherwise.
396*9880d681SAndroid Build Coastguard Worker   bool fieldFromInsn(uint64_t &Field, insn_t &Insn, unsigned StartBit,
397*9880d681SAndroid Build Coastguard Worker                      unsigned NumBits) const;
398*9880d681SAndroid Build Coastguard Worker 
399*9880d681SAndroid Build Coastguard Worker   /// dumpFilterArray - dumpFilterArray prints out debugging info for the given
400*9880d681SAndroid Build Coastguard Worker   /// filter array as a series of chars.
401*9880d681SAndroid Build Coastguard Worker   void dumpFilterArray(raw_ostream &o,
402*9880d681SAndroid Build Coastguard Worker                        const std::vector<bit_value_t> & filter) const;
403*9880d681SAndroid Build Coastguard Worker 
404*9880d681SAndroid Build Coastguard Worker   /// dumpStack - dumpStack traverses the filter chooser chain and calls
405*9880d681SAndroid Build Coastguard Worker   /// dumpFilterArray on each filter chooser up to the top level one.
406*9880d681SAndroid Build Coastguard Worker   void dumpStack(raw_ostream &o, const char *prefix) const;
407*9880d681SAndroid Build Coastguard Worker 
bestFilter()408*9880d681SAndroid Build Coastguard Worker   Filter &bestFilter() {
409*9880d681SAndroid Build Coastguard Worker     assert(BestIndex != -1 && "BestIndex not set");
410*9880d681SAndroid Build Coastguard Worker     return Filters[BestIndex];
411*9880d681SAndroid Build Coastguard Worker   }
412*9880d681SAndroid Build Coastguard Worker 
PositionFiltered(unsigned i) const413*9880d681SAndroid Build Coastguard Worker   bool PositionFiltered(unsigned i) const {
414*9880d681SAndroid Build Coastguard Worker     return ValueSet(FilterBitValues[i]);
415*9880d681SAndroid Build Coastguard Worker   }
416*9880d681SAndroid Build Coastguard Worker 
417*9880d681SAndroid Build Coastguard Worker   // Calculates the island(s) needed to decode the instruction.
418*9880d681SAndroid Build Coastguard Worker   // This returns a lit of undecoded bits of an instructions, for example,
419*9880d681SAndroid Build Coastguard Worker   // Inst{20} = 1 && Inst{3-0} == 0b1111 represents two islands of yet-to-be
420*9880d681SAndroid Build Coastguard Worker   // decoded bits in order to verify that the instruction matches the Opcode.
421*9880d681SAndroid Build Coastguard Worker   unsigned getIslands(std::vector<unsigned> &StartBits,
422*9880d681SAndroid Build Coastguard Worker                       std::vector<unsigned> &EndBits,
423*9880d681SAndroid Build Coastguard Worker                       std::vector<uint64_t> &FieldVals,
424*9880d681SAndroid Build Coastguard Worker                       const insn_t &Insn) const;
425*9880d681SAndroid Build Coastguard Worker 
426*9880d681SAndroid Build Coastguard Worker   // Emits code to check the Predicates member of an instruction are true.
427*9880d681SAndroid Build Coastguard Worker   // Returns true if predicate matches were emitted, false otherwise.
428*9880d681SAndroid Build Coastguard Worker   bool emitPredicateMatch(raw_ostream &o, unsigned &Indentation,
429*9880d681SAndroid Build Coastguard Worker                           unsigned Opc) const;
430*9880d681SAndroid Build Coastguard Worker 
431*9880d681SAndroid Build Coastguard Worker   bool doesOpcodeNeedPredicate(unsigned Opc) const;
432*9880d681SAndroid Build Coastguard Worker   unsigned getPredicateIndex(DecoderTableInfo &TableInfo, StringRef P) const;
433*9880d681SAndroid Build Coastguard Worker   void emitPredicateTableEntry(DecoderTableInfo &TableInfo,
434*9880d681SAndroid Build Coastguard Worker                                unsigned Opc) const;
435*9880d681SAndroid Build Coastguard Worker 
436*9880d681SAndroid Build Coastguard Worker   void emitSoftFailTableEntry(DecoderTableInfo &TableInfo,
437*9880d681SAndroid Build Coastguard Worker                               unsigned Opc) const;
438*9880d681SAndroid Build Coastguard Worker 
439*9880d681SAndroid Build Coastguard Worker   // Emits table entries to decode the singleton.
440*9880d681SAndroid Build Coastguard Worker   void emitSingletonTableEntry(DecoderTableInfo &TableInfo,
441*9880d681SAndroid Build Coastguard Worker                                unsigned Opc) const;
442*9880d681SAndroid Build Coastguard Worker 
443*9880d681SAndroid Build Coastguard Worker   // Emits code to decode the singleton, and then to decode the rest.
444*9880d681SAndroid Build Coastguard Worker   void emitSingletonTableEntry(DecoderTableInfo &TableInfo,
445*9880d681SAndroid Build Coastguard Worker                                const Filter &Best) const;
446*9880d681SAndroid Build Coastguard Worker 
447*9880d681SAndroid Build Coastguard Worker   void emitBinaryParser(raw_ostream &o, unsigned &Indentation,
448*9880d681SAndroid Build Coastguard Worker                         const OperandInfo &OpInfo,
449*9880d681SAndroid Build Coastguard Worker                         bool &OpHasCompleteDecoder) const;
450*9880d681SAndroid Build Coastguard Worker 
451*9880d681SAndroid Build Coastguard Worker   void emitDecoder(raw_ostream &OS, unsigned Indentation, unsigned Opc,
452*9880d681SAndroid Build Coastguard Worker                    bool &HasCompleteDecoder) const;
453*9880d681SAndroid Build Coastguard Worker   unsigned getDecoderIndex(DecoderSet &Decoders, unsigned Opc,
454*9880d681SAndroid Build Coastguard Worker                            bool &HasCompleteDecoder) const;
455*9880d681SAndroid Build Coastguard Worker 
456*9880d681SAndroid Build Coastguard Worker   // Assign a single filter and run with it.
457*9880d681SAndroid Build Coastguard Worker   void runSingleFilter(unsigned startBit, unsigned numBit, bool mixed);
458*9880d681SAndroid Build Coastguard Worker 
459*9880d681SAndroid Build Coastguard Worker   // reportRegion is a helper function for filterProcessor to mark a region as
460*9880d681SAndroid Build Coastguard Worker   // eligible for use as a filter region.
461*9880d681SAndroid Build Coastguard Worker   void reportRegion(bitAttr_t RA, unsigned StartBit, unsigned BitIndex,
462*9880d681SAndroid Build Coastguard Worker                     bool AllowMixed);
463*9880d681SAndroid Build Coastguard Worker 
464*9880d681SAndroid Build Coastguard Worker   // FilterProcessor scans the well-known encoding bits of the instructions and
465*9880d681SAndroid Build Coastguard Worker   // builds up a list of candidate filters.  It chooses the best filter and
466*9880d681SAndroid Build Coastguard Worker   // recursively descends down the decoding tree.
467*9880d681SAndroid Build Coastguard Worker   bool filterProcessor(bool AllowMixed, bool Greedy = true);
468*9880d681SAndroid Build Coastguard Worker 
469*9880d681SAndroid Build Coastguard Worker   // Decides on the best configuration of filter(s) to use in order to decode
470*9880d681SAndroid Build Coastguard Worker   // the instructions.  A conflict of instructions may occur, in which case we
471*9880d681SAndroid Build Coastguard Worker   // dump the conflict set to the standard error.
472*9880d681SAndroid Build Coastguard Worker   void doFilter();
473*9880d681SAndroid Build Coastguard Worker 
474*9880d681SAndroid Build Coastguard Worker public:
475*9880d681SAndroid Build Coastguard Worker   // emitTableEntries - Emit state machine entries to decode our share of
476*9880d681SAndroid Build Coastguard Worker   // instructions.
477*9880d681SAndroid Build Coastguard Worker   void emitTableEntries(DecoderTableInfo &TableInfo) const;
478*9880d681SAndroid Build Coastguard Worker };
479*9880d681SAndroid Build Coastguard Worker } // End anonymous namespace
480*9880d681SAndroid Build Coastguard Worker 
481*9880d681SAndroid Build Coastguard Worker ///////////////////////////
482*9880d681SAndroid Build Coastguard Worker //                       //
483*9880d681SAndroid Build Coastguard Worker // Filter Implementation //
484*9880d681SAndroid Build Coastguard Worker //                       //
485*9880d681SAndroid Build Coastguard Worker ///////////////////////////
486*9880d681SAndroid Build Coastguard Worker 
Filter(Filter && f)487*9880d681SAndroid Build Coastguard Worker Filter::Filter(Filter &&f)
488*9880d681SAndroid Build Coastguard Worker   : Owner(f.Owner), StartBit(f.StartBit), NumBits(f.NumBits), Mixed(f.Mixed),
489*9880d681SAndroid Build Coastguard Worker     FilteredInstructions(std::move(f.FilteredInstructions)),
490*9880d681SAndroid Build Coastguard Worker     VariableInstructions(std::move(f.VariableInstructions)),
491*9880d681SAndroid Build Coastguard Worker     FilterChooserMap(std::move(f.FilterChooserMap)), NumFiltered(f.NumFiltered),
492*9880d681SAndroid Build Coastguard Worker     LastOpcFiltered(f.LastOpcFiltered) {
493*9880d681SAndroid Build Coastguard Worker }
494*9880d681SAndroid Build Coastguard Worker 
Filter(FilterChooser & owner,unsigned startBit,unsigned numBits,bool mixed)495*9880d681SAndroid Build Coastguard Worker Filter::Filter(FilterChooser &owner, unsigned startBit, unsigned numBits,
496*9880d681SAndroid Build Coastguard Worker                bool mixed)
497*9880d681SAndroid Build Coastguard Worker   : Owner(&owner), StartBit(startBit), NumBits(numBits), Mixed(mixed) {
498*9880d681SAndroid Build Coastguard Worker   assert(StartBit + NumBits - 1 < Owner->BitWidth);
499*9880d681SAndroid Build Coastguard Worker 
500*9880d681SAndroid Build Coastguard Worker   NumFiltered = 0;
501*9880d681SAndroid Build Coastguard Worker   LastOpcFiltered = 0;
502*9880d681SAndroid Build Coastguard Worker 
503*9880d681SAndroid Build Coastguard Worker   for (unsigned i = 0, e = Owner->Opcodes.size(); i != e; ++i) {
504*9880d681SAndroid Build Coastguard Worker     insn_t Insn;
505*9880d681SAndroid Build Coastguard Worker 
506*9880d681SAndroid Build Coastguard Worker     // Populates the insn given the uid.
507*9880d681SAndroid Build Coastguard Worker     Owner->insnWithID(Insn, Owner->Opcodes[i]);
508*9880d681SAndroid Build Coastguard Worker 
509*9880d681SAndroid Build Coastguard Worker     uint64_t Field;
510*9880d681SAndroid Build Coastguard Worker     // Scans the segment for possibly well-specified encoding bits.
511*9880d681SAndroid Build Coastguard Worker     bool ok = Owner->fieldFromInsn(Field, Insn, StartBit, NumBits);
512*9880d681SAndroid Build Coastguard Worker 
513*9880d681SAndroid Build Coastguard Worker     if (ok) {
514*9880d681SAndroid Build Coastguard Worker       // The encoding bits are well-known.  Lets add the uid of the
515*9880d681SAndroid Build Coastguard Worker       // instruction into the bucket keyed off the constant field value.
516*9880d681SAndroid Build Coastguard Worker       LastOpcFiltered = Owner->Opcodes[i];
517*9880d681SAndroid Build Coastguard Worker       FilteredInstructions[Field].push_back(LastOpcFiltered);
518*9880d681SAndroid Build Coastguard Worker       ++NumFiltered;
519*9880d681SAndroid Build Coastguard Worker     } else {
520*9880d681SAndroid Build Coastguard Worker       // Some of the encoding bit(s) are unspecified.  This contributes to
521*9880d681SAndroid Build Coastguard Worker       // one additional member of "Variable" instructions.
522*9880d681SAndroid Build Coastguard Worker       VariableInstructions.push_back(Owner->Opcodes[i]);
523*9880d681SAndroid Build Coastguard Worker     }
524*9880d681SAndroid Build Coastguard Worker   }
525*9880d681SAndroid Build Coastguard Worker 
526*9880d681SAndroid Build Coastguard Worker   assert((FilteredInstructions.size() + VariableInstructions.size() > 0)
527*9880d681SAndroid Build Coastguard Worker          && "Filter returns no instruction categories");
528*9880d681SAndroid Build Coastguard Worker }
529*9880d681SAndroid Build Coastguard Worker 
~Filter()530*9880d681SAndroid Build Coastguard Worker Filter::~Filter() {
531*9880d681SAndroid Build Coastguard Worker }
532*9880d681SAndroid Build Coastguard Worker 
533*9880d681SAndroid Build Coastguard Worker // Divides the decoding task into sub tasks and delegates them to the
534*9880d681SAndroid Build Coastguard Worker // inferior FilterChooser's.
535*9880d681SAndroid Build Coastguard Worker //
536*9880d681SAndroid Build Coastguard Worker // A special case arises when there's only one entry in the filtered
537*9880d681SAndroid Build Coastguard Worker // instructions.  In order to unambiguously decode the singleton, we need to
538*9880d681SAndroid Build Coastguard Worker // match the remaining undecoded encoding bits against the singleton.
recurse()539*9880d681SAndroid Build Coastguard Worker void Filter::recurse() {
540*9880d681SAndroid Build Coastguard Worker   // Starts by inheriting our parent filter chooser's filter bit values.
541*9880d681SAndroid Build Coastguard Worker   std::vector<bit_value_t> BitValueArray(Owner->FilterBitValues);
542*9880d681SAndroid Build Coastguard Worker 
543*9880d681SAndroid Build Coastguard Worker   if (!VariableInstructions.empty()) {
544*9880d681SAndroid Build Coastguard Worker     // Conservatively marks each segment position as BIT_UNSET.
545*9880d681SAndroid Build Coastguard Worker     for (unsigned bitIndex = 0; bitIndex < NumBits; ++bitIndex)
546*9880d681SAndroid Build Coastguard Worker       BitValueArray[StartBit + bitIndex] = BIT_UNSET;
547*9880d681SAndroid Build Coastguard Worker 
548*9880d681SAndroid Build Coastguard Worker     // Delegates to an inferior filter chooser for further processing on this
549*9880d681SAndroid Build Coastguard Worker     // group of instructions whose segment values are variable.
550*9880d681SAndroid Build Coastguard Worker     FilterChooserMap.insert(
551*9880d681SAndroid Build Coastguard Worker         std::make_pair(-1U, llvm::make_unique<FilterChooser>(
552*9880d681SAndroid Build Coastguard Worker                                 Owner->AllInstructions, VariableInstructions,
553*9880d681SAndroid Build Coastguard Worker                                 Owner->Operands, BitValueArray, *Owner)));
554*9880d681SAndroid Build Coastguard Worker   }
555*9880d681SAndroid Build Coastguard Worker 
556*9880d681SAndroid Build Coastguard Worker   // No need to recurse for a singleton filtered instruction.
557*9880d681SAndroid Build Coastguard Worker   // See also Filter::emit*().
558*9880d681SAndroid Build Coastguard Worker   if (getNumFiltered() == 1) {
559*9880d681SAndroid Build Coastguard Worker     assert(FilterChooserMap.size() == 1);
560*9880d681SAndroid Build Coastguard Worker     return;
561*9880d681SAndroid Build Coastguard Worker   }
562*9880d681SAndroid Build Coastguard Worker 
563*9880d681SAndroid Build Coastguard Worker   // Otherwise, create sub choosers.
564*9880d681SAndroid Build Coastguard Worker   for (const auto &Inst : FilteredInstructions) {
565*9880d681SAndroid Build Coastguard Worker 
566*9880d681SAndroid Build Coastguard Worker     // Marks all the segment positions with either BIT_TRUE or BIT_FALSE.
567*9880d681SAndroid Build Coastguard Worker     for (unsigned bitIndex = 0; bitIndex < NumBits; ++bitIndex) {
568*9880d681SAndroid Build Coastguard Worker       if (Inst.first & (1ULL << bitIndex))
569*9880d681SAndroid Build Coastguard Worker         BitValueArray[StartBit + bitIndex] = BIT_TRUE;
570*9880d681SAndroid Build Coastguard Worker       else
571*9880d681SAndroid Build Coastguard Worker         BitValueArray[StartBit + bitIndex] = BIT_FALSE;
572*9880d681SAndroid Build Coastguard Worker     }
573*9880d681SAndroid Build Coastguard Worker 
574*9880d681SAndroid Build Coastguard Worker     // Delegates to an inferior filter chooser for further processing on this
575*9880d681SAndroid Build Coastguard Worker     // category of instructions.
576*9880d681SAndroid Build Coastguard Worker     FilterChooserMap.insert(std::make_pair(
577*9880d681SAndroid Build Coastguard Worker         Inst.first, llvm::make_unique<FilterChooser>(
578*9880d681SAndroid Build Coastguard Worker                                 Owner->AllInstructions, Inst.second,
579*9880d681SAndroid Build Coastguard Worker                                 Owner->Operands, BitValueArray, *Owner)));
580*9880d681SAndroid Build Coastguard Worker   }
581*9880d681SAndroid Build Coastguard Worker }
582*9880d681SAndroid Build Coastguard Worker 
resolveTableFixups(DecoderTable & Table,const FixupList & Fixups,uint32_t DestIdx)583*9880d681SAndroid Build Coastguard Worker static void resolveTableFixups(DecoderTable &Table, const FixupList &Fixups,
584*9880d681SAndroid Build Coastguard Worker                                uint32_t DestIdx) {
585*9880d681SAndroid Build Coastguard Worker   // Any NumToSkip fixups in the current scope can resolve to the
586*9880d681SAndroid Build Coastguard Worker   // current location.
587*9880d681SAndroid Build Coastguard Worker   for (FixupList::const_reverse_iterator I = Fixups.rbegin(),
588*9880d681SAndroid Build Coastguard Worker                                          E = Fixups.rend();
589*9880d681SAndroid Build Coastguard Worker        I != E; ++I) {
590*9880d681SAndroid Build Coastguard Worker     // Calculate the distance from the byte following the fixup entry byte
591*9880d681SAndroid Build Coastguard Worker     // to the destination. The Target is calculated from after the 16-bit
592*9880d681SAndroid Build Coastguard Worker     // NumToSkip entry itself, so subtract two  from the displacement here
593*9880d681SAndroid Build Coastguard Worker     // to account for that.
594*9880d681SAndroid Build Coastguard Worker     uint32_t FixupIdx = *I;
595*9880d681SAndroid Build Coastguard Worker     uint32_t Delta = DestIdx - FixupIdx - 2;
596*9880d681SAndroid Build Coastguard Worker     // Our NumToSkip entries are 16-bits. Make sure our table isn't too
597*9880d681SAndroid Build Coastguard Worker     // big.
598*9880d681SAndroid Build Coastguard Worker     assert(Delta < 65536U && "disassembler decoding table too large!");
599*9880d681SAndroid Build Coastguard Worker     Table[FixupIdx] = (uint8_t)Delta;
600*9880d681SAndroid Build Coastguard Worker     Table[FixupIdx + 1] = (uint8_t)(Delta >> 8);
601*9880d681SAndroid Build Coastguard Worker   }
602*9880d681SAndroid Build Coastguard Worker }
603*9880d681SAndroid Build Coastguard Worker 
604*9880d681SAndroid Build Coastguard Worker // Emit table entries to decode instructions given a segment or segments
605*9880d681SAndroid Build Coastguard Worker // of bits.
emitTableEntry(DecoderTableInfo & TableInfo) const606*9880d681SAndroid Build Coastguard Worker void Filter::emitTableEntry(DecoderTableInfo &TableInfo) const {
607*9880d681SAndroid Build Coastguard Worker   TableInfo.Table.push_back(MCD::OPC_ExtractField);
608*9880d681SAndroid Build Coastguard Worker   TableInfo.Table.push_back(StartBit);
609*9880d681SAndroid Build Coastguard Worker   TableInfo.Table.push_back(NumBits);
610*9880d681SAndroid Build Coastguard Worker 
611*9880d681SAndroid Build Coastguard Worker   // A new filter entry begins a new scope for fixup resolution.
612*9880d681SAndroid Build Coastguard Worker   TableInfo.FixupStack.emplace_back();
613*9880d681SAndroid Build Coastguard Worker 
614*9880d681SAndroid Build Coastguard Worker   DecoderTable &Table = TableInfo.Table;
615*9880d681SAndroid Build Coastguard Worker 
616*9880d681SAndroid Build Coastguard Worker   size_t PrevFilter = 0;
617*9880d681SAndroid Build Coastguard Worker   bool HasFallthrough = false;
618*9880d681SAndroid Build Coastguard Worker   for (auto &Filter : FilterChooserMap) {
619*9880d681SAndroid Build Coastguard Worker     // Field value -1 implies a non-empty set of variable instructions.
620*9880d681SAndroid Build Coastguard Worker     // See also recurse().
621*9880d681SAndroid Build Coastguard Worker     if (Filter.first == (unsigned)-1) {
622*9880d681SAndroid Build Coastguard Worker       HasFallthrough = true;
623*9880d681SAndroid Build Coastguard Worker 
624*9880d681SAndroid Build Coastguard Worker       // Each scope should always have at least one filter value to check
625*9880d681SAndroid Build Coastguard Worker       // for.
626*9880d681SAndroid Build Coastguard Worker       assert(PrevFilter != 0 && "empty filter set!");
627*9880d681SAndroid Build Coastguard Worker       FixupList &CurScope = TableInfo.FixupStack.back();
628*9880d681SAndroid Build Coastguard Worker       // Resolve any NumToSkip fixups in the current scope.
629*9880d681SAndroid Build Coastguard Worker       resolveTableFixups(Table, CurScope, Table.size());
630*9880d681SAndroid Build Coastguard Worker       CurScope.clear();
631*9880d681SAndroid Build Coastguard Worker       PrevFilter = 0;  // Don't re-process the filter's fallthrough.
632*9880d681SAndroid Build Coastguard Worker     } else {
633*9880d681SAndroid Build Coastguard Worker       Table.push_back(MCD::OPC_FilterValue);
634*9880d681SAndroid Build Coastguard Worker       // Encode and emit the value to filter against.
635*9880d681SAndroid Build Coastguard Worker       uint8_t Buffer[8];
636*9880d681SAndroid Build Coastguard Worker       unsigned Len = encodeULEB128(Filter.first, Buffer);
637*9880d681SAndroid Build Coastguard Worker       Table.insert(Table.end(), Buffer, Buffer + Len);
638*9880d681SAndroid Build Coastguard Worker       // Reserve space for the NumToSkip entry. We'll backpatch the value
639*9880d681SAndroid Build Coastguard Worker       // later.
640*9880d681SAndroid Build Coastguard Worker       PrevFilter = Table.size();
641*9880d681SAndroid Build Coastguard Worker       Table.push_back(0);
642*9880d681SAndroid Build Coastguard Worker       Table.push_back(0);
643*9880d681SAndroid Build Coastguard Worker     }
644*9880d681SAndroid Build Coastguard Worker 
645*9880d681SAndroid Build Coastguard Worker     // We arrive at a category of instructions with the same segment value.
646*9880d681SAndroid Build Coastguard Worker     // Now delegate to the sub filter chooser for further decodings.
647*9880d681SAndroid Build Coastguard Worker     // The case may fallthrough, which happens if the remaining well-known
648*9880d681SAndroid Build Coastguard Worker     // encoding bits do not match exactly.
649*9880d681SAndroid Build Coastguard Worker     Filter.second->emitTableEntries(TableInfo);
650*9880d681SAndroid Build Coastguard Worker 
651*9880d681SAndroid Build Coastguard Worker     // Now that we've emitted the body of the handler, update the NumToSkip
652*9880d681SAndroid Build Coastguard Worker     // of the filter itself to be able to skip forward when false. Subtract
653*9880d681SAndroid Build Coastguard Worker     // two as to account for the width of the NumToSkip field itself.
654*9880d681SAndroid Build Coastguard Worker     if (PrevFilter) {
655*9880d681SAndroid Build Coastguard Worker       uint32_t NumToSkip = Table.size() - PrevFilter - 2;
656*9880d681SAndroid Build Coastguard Worker       assert(NumToSkip < 65536U && "disassembler decoding table too large!");
657*9880d681SAndroid Build Coastguard Worker       Table[PrevFilter] = (uint8_t)NumToSkip;
658*9880d681SAndroid Build Coastguard Worker       Table[PrevFilter + 1] = (uint8_t)(NumToSkip >> 8);
659*9880d681SAndroid Build Coastguard Worker     }
660*9880d681SAndroid Build Coastguard Worker   }
661*9880d681SAndroid Build Coastguard Worker 
662*9880d681SAndroid Build Coastguard Worker   // Any remaining unresolved fixups bubble up to the parent fixup scope.
663*9880d681SAndroid Build Coastguard Worker   assert(TableInfo.FixupStack.size() > 1 && "fixup stack underflow!");
664*9880d681SAndroid Build Coastguard Worker   FixupScopeList::iterator Source = TableInfo.FixupStack.end() - 1;
665*9880d681SAndroid Build Coastguard Worker   FixupScopeList::iterator Dest = Source - 1;
666*9880d681SAndroid Build Coastguard Worker   Dest->insert(Dest->end(), Source->begin(), Source->end());
667*9880d681SAndroid Build Coastguard Worker   TableInfo.FixupStack.pop_back();
668*9880d681SAndroid Build Coastguard Worker 
669*9880d681SAndroid Build Coastguard Worker   // If there is no fallthrough, then the final filter should get fixed
670*9880d681SAndroid Build Coastguard Worker   // up according to the enclosing scope rather than the current position.
671*9880d681SAndroid Build Coastguard Worker   if (!HasFallthrough)
672*9880d681SAndroid Build Coastguard Worker     TableInfo.FixupStack.back().push_back(PrevFilter);
673*9880d681SAndroid Build Coastguard Worker }
674*9880d681SAndroid Build Coastguard Worker 
675*9880d681SAndroid Build Coastguard Worker // Returns the number of fanout produced by the filter.  More fanout implies
676*9880d681SAndroid Build Coastguard Worker // the filter distinguishes more categories of instructions.
usefulness() const677*9880d681SAndroid Build Coastguard Worker unsigned Filter::usefulness() const {
678*9880d681SAndroid Build Coastguard Worker   if (!VariableInstructions.empty())
679*9880d681SAndroid Build Coastguard Worker     return FilteredInstructions.size();
680*9880d681SAndroid Build Coastguard Worker   else
681*9880d681SAndroid Build Coastguard Worker     return FilteredInstructions.size() + 1;
682*9880d681SAndroid Build Coastguard Worker }
683*9880d681SAndroid Build Coastguard Worker 
684*9880d681SAndroid Build Coastguard Worker //////////////////////////////////
685*9880d681SAndroid Build Coastguard Worker //                              //
686*9880d681SAndroid Build Coastguard Worker // Filterchooser Implementation //
687*9880d681SAndroid Build Coastguard Worker //                              //
688*9880d681SAndroid Build Coastguard Worker //////////////////////////////////
689*9880d681SAndroid Build Coastguard Worker 
690*9880d681SAndroid Build Coastguard Worker // Emit the decoder state machine table.
emitTable(formatted_raw_ostream & OS,DecoderTable & Table,unsigned Indentation,unsigned BitWidth,StringRef Namespace) const691*9880d681SAndroid Build Coastguard Worker void FixedLenDecoderEmitter::emitTable(formatted_raw_ostream &OS,
692*9880d681SAndroid Build Coastguard Worker                                        DecoderTable &Table,
693*9880d681SAndroid Build Coastguard Worker                                        unsigned Indentation,
694*9880d681SAndroid Build Coastguard Worker                                        unsigned BitWidth,
695*9880d681SAndroid Build Coastguard Worker                                        StringRef Namespace) const {
696*9880d681SAndroid Build Coastguard Worker   OS.indent(Indentation) << "static const uint8_t DecoderTable" << Namespace
697*9880d681SAndroid Build Coastguard Worker     << BitWidth << "[] = {\n";
698*9880d681SAndroid Build Coastguard Worker 
699*9880d681SAndroid Build Coastguard Worker   Indentation += 2;
700*9880d681SAndroid Build Coastguard Worker 
701*9880d681SAndroid Build Coastguard Worker   // FIXME: We may be able to use the NumToSkip values to recover
702*9880d681SAndroid Build Coastguard Worker   // appropriate indentation levels.
703*9880d681SAndroid Build Coastguard Worker   DecoderTable::const_iterator I = Table.begin();
704*9880d681SAndroid Build Coastguard Worker   DecoderTable::const_iterator E = Table.end();
705*9880d681SAndroid Build Coastguard Worker   while (I != E) {
706*9880d681SAndroid Build Coastguard Worker     assert (I < E && "incomplete decode table entry!");
707*9880d681SAndroid Build Coastguard Worker 
708*9880d681SAndroid Build Coastguard Worker     uint64_t Pos = I - Table.begin();
709*9880d681SAndroid Build Coastguard Worker     OS << "/* " << Pos << " */";
710*9880d681SAndroid Build Coastguard Worker     OS.PadToColumn(12);
711*9880d681SAndroid Build Coastguard Worker 
712*9880d681SAndroid Build Coastguard Worker     switch (*I) {
713*9880d681SAndroid Build Coastguard Worker     default:
714*9880d681SAndroid Build Coastguard Worker       PrintFatalError("invalid decode table opcode");
715*9880d681SAndroid Build Coastguard Worker     case MCD::OPC_ExtractField: {
716*9880d681SAndroid Build Coastguard Worker       ++I;
717*9880d681SAndroid Build Coastguard Worker       unsigned Start = *I++;
718*9880d681SAndroid Build Coastguard Worker       unsigned Len = *I++;
719*9880d681SAndroid Build Coastguard Worker       OS.indent(Indentation) << "MCD::OPC_ExtractField, " << Start << ", "
720*9880d681SAndroid Build Coastguard Worker         << Len << ",  // Inst{";
721*9880d681SAndroid Build Coastguard Worker       if (Len > 1)
722*9880d681SAndroid Build Coastguard Worker         OS << (Start + Len - 1) << "-";
723*9880d681SAndroid Build Coastguard Worker       OS << Start << "} ...\n";
724*9880d681SAndroid Build Coastguard Worker       break;
725*9880d681SAndroid Build Coastguard Worker     }
726*9880d681SAndroid Build Coastguard Worker     case MCD::OPC_FilterValue: {
727*9880d681SAndroid Build Coastguard Worker       ++I;
728*9880d681SAndroid Build Coastguard Worker       OS.indent(Indentation) << "MCD::OPC_FilterValue, ";
729*9880d681SAndroid Build Coastguard Worker       // The filter value is ULEB128 encoded.
730*9880d681SAndroid Build Coastguard Worker       while (*I >= 128)
731*9880d681SAndroid Build Coastguard Worker         OS << (unsigned)*I++ << ", ";
732*9880d681SAndroid Build Coastguard Worker       OS << (unsigned)*I++ << ", ";
733*9880d681SAndroid Build Coastguard Worker 
734*9880d681SAndroid Build Coastguard Worker       // 16-bit numtoskip value.
735*9880d681SAndroid Build Coastguard Worker       uint8_t Byte = *I++;
736*9880d681SAndroid Build Coastguard Worker       uint32_t NumToSkip = Byte;
737*9880d681SAndroid Build Coastguard Worker       OS << (unsigned)Byte << ", ";
738*9880d681SAndroid Build Coastguard Worker       Byte = *I++;
739*9880d681SAndroid Build Coastguard Worker       OS << (unsigned)Byte << ", ";
740*9880d681SAndroid Build Coastguard Worker       NumToSkip |= Byte << 8;
741*9880d681SAndroid Build Coastguard Worker       OS << "// Skip to: " << ((I - Table.begin()) + NumToSkip) << "\n";
742*9880d681SAndroid Build Coastguard Worker       break;
743*9880d681SAndroid Build Coastguard Worker     }
744*9880d681SAndroid Build Coastguard Worker     case MCD::OPC_CheckField: {
745*9880d681SAndroid Build Coastguard Worker       ++I;
746*9880d681SAndroid Build Coastguard Worker       unsigned Start = *I++;
747*9880d681SAndroid Build Coastguard Worker       unsigned Len = *I++;
748*9880d681SAndroid Build Coastguard Worker       OS.indent(Indentation) << "MCD::OPC_CheckField, " << Start << ", "
749*9880d681SAndroid Build Coastguard Worker         << Len << ", ";// << Val << ", " << NumToSkip << ",\n";
750*9880d681SAndroid Build Coastguard Worker       // ULEB128 encoded field value.
751*9880d681SAndroid Build Coastguard Worker       for (; *I >= 128; ++I)
752*9880d681SAndroid Build Coastguard Worker         OS << (unsigned)*I << ", ";
753*9880d681SAndroid Build Coastguard Worker       OS << (unsigned)*I++ << ", ";
754*9880d681SAndroid Build Coastguard Worker       // 16-bit numtoskip value.
755*9880d681SAndroid Build Coastguard Worker       uint8_t Byte = *I++;
756*9880d681SAndroid Build Coastguard Worker       uint32_t NumToSkip = Byte;
757*9880d681SAndroid Build Coastguard Worker       OS << (unsigned)Byte << ", ";
758*9880d681SAndroid Build Coastguard Worker       Byte = *I++;
759*9880d681SAndroid Build Coastguard Worker       OS << (unsigned)Byte << ", ";
760*9880d681SAndroid Build Coastguard Worker       NumToSkip |= Byte << 8;
761*9880d681SAndroid Build Coastguard Worker       OS << "// Skip to: " << ((I - Table.begin()) + NumToSkip) << "\n";
762*9880d681SAndroid Build Coastguard Worker       break;
763*9880d681SAndroid Build Coastguard Worker     }
764*9880d681SAndroid Build Coastguard Worker     case MCD::OPC_CheckPredicate: {
765*9880d681SAndroid Build Coastguard Worker       ++I;
766*9880d681SAndroid Build Coastguard Worker       OS.indent(Indentation) << "MCD::OPC_CheckPredicate, ";
767*9880d681SAndroid Build Coastguard Worker       for (; *I >= 128; ++I)
768*9880d681SAndroid Build Coastguard Worker         OS << (unsigned)*I << ", ";
769*9880d681SAndroid Build Coastguard Worker       OS << (unsigned)*I++ << ", ";
770*9880d681SAndroid Build Coastguard Worker 
771*9880d681SAndroid Build Coastguard Worker       // 16-bit numtoskip value.
772*9880d681SAndroid Build Coastguard Worker       uint8_t Byte = *I++;
773*9880d681SAndroid Build Coastguard Worker       uint32_t NumToSkip = Byte;
774*9880d681SAndroid Build Coastguard Worker       OS << (unsigned)Byte << ", ";
775*9880d681SAndroid Build Coastguard Worker       Byte = *I++;
776*9880d681SAndroid Build Coastguard Worker       OS << (unsigned)Byte << ", ";
777*9880d681SAndroid Build Coastguard Worker       NumToSkip |= Byte << 8;
778*9880d681SAndroid Build Coastguard Worker       OS << "// Skip to: " << ((I - Table.begin()) + NumToSkip) << "\n";
779*9880d681SAndroid Build Coastguard Worker       break;
780*9880d681SAndroid Build Coastguard Worker     }
781*9880d681SAndroid Build Coastguard Worker     case MCD::OPC_Decode:
782*9880d681SAndroid Build Coastguard Worker     case MCD::OPC_TryDecode: {
783*9880d681SAndroid Build Coastguard Worker       bool IsTry = *I == MCD::OPC_TryDecode;
784*9880d681SAndroid Build Coastguard Worker       ++I;
785*9880d681SAndroid Build Coastguard Worker       // Extract the ULEB128 encoded Opcode to a buffer.
786*9880d681SAndroid Build Coastguard Worker       uint8_t Buffer[8], *p = Buffer;
787*9880d681SAndroid Build Coastguard Worker       while ((*p++ = *I++) >= 128)
788*9880d681SAndroid Build Coastguard Worker         assert((p - Buffer) <= (ptrdiff_t)sizeof(Buffer)
789*9880d681SAndroid Build Coastguard Worker                && "ULEB128 value too large!");
790*9880d681SAndroid Build Coastguard Worker       // Decode the Opcode value.
791*9880d681SAndroid Build Coastguard Worker       unsigned Opc = decodeULEB128(Buffer);
792*9880d681SAndroid Build Coastguard Worker       OS.indent(Indentation) << "MCD::OPC_" << (IsTry ? "Try" : "")
793*9880d681SAndroid Build Coastguard Worker         << "Decode, ";
794*9880d681SAndroid Build Coastguard Worker       for (p = Buffer; *p >= 128; ++p)
795*9880d681SAndroid Build Coastguard Worker         OS << (unsigned)*p << ", ";
796*9880d681SAndroid Build Coastguard Worker       OS << (unsigned)*p << ", ";
797*9880d681SAndroid Build Coastguard Worker 
798*9880d681SAndroid Build Coastguard Worker       // Decoder index.
799*9880d681SAndroid Build Coastguard Worker       for (; *I >= 128; ++I)
800*9880d681SAndroid Build Coastguard Worker         OS << (unsigned)*I << ", ";
801*9880d681SAndroid Build Coastguard Worker       OS << (unsigned)*I++ << ", ";
802*9880d681SAndroid Build Coastguard Worker 
803*9880d681SAndroid Build Coastguard Worker       if (!IsTry) {
804*9880d681SAndroid Build Coastguard Worker         OS << "// Opcode: "
805*9880d681SAndroid Build Coastguard Worker            << NumberedInstructions[Opc]->TheDef->getName() << "\n";
806*9880d681SAndroid Build Coastguard Worker         break;
807*9880d681SAndroid Build Coastguard Worker       }
808*9880d681SAndroid Build Coastguard Worker 
809*9880d681SAndroid Build Coastguard Worker       // Fallthrough for OPC_TryDecode.
810*9880d681SAndroid Build Coastguard Worker 
811*9880d681SAndroid Build Coastguard Worker       // 16-bit numtoskip value.
812*9880d681SAndroid Build Coastguard Worker       uint8_t Byte = *I++;
813*9880d681SAndroid Build Coastguard Worker       uint32_t NumToSkip = Byte;
814*9880d681SAndroid Build Coastguard Worker       OS << (unsigned)Byte << ", ";
815*9880d681SAndroid Build Coastguard Worker       Byte = *I++;
816*9880d681SAndroid Build Coastguard Worker       OS << (unsigned)Byte << ", ";
817*9880d681SAndroid Build Coastguard Worker       NumToSkip |= Byte << 8;
818*9880d681SAndroid Build Coastguard Worker 
819*9880d681SAndroid Build Coastguard Worker       OS << "// Opcode: "
820*9880d681SAndroid Build Coastguard Worker          << NumberedInstructions[Opc]->TheDef->getName()
821*9880d681SAndroid Build Coastguard Worker          << ", skip to: " << ((I - Table.begin()) + NumToSkip) << "\n";
822*9880d681SAndroid Build Coastguard Worker       break;
823*9880d681SAndroid Build Coastguard Worker     }
824*9880d681SAndroid Build Coastguard Worker     case MCD::OPC_SoftFail: {
825*9880d681SAndroid Build Coastguard Worker       ++I;
826*9880d681SAndroid Build Coastguard Worker       OS.indent(Indentation) << "MCD::OPC_SoftFail";
827*9880d681SAndroid Build Coastguard Worker       // Positive mask
828*9880d681SAndroid Build Coastguard Worker       uint64_t Value = 0;
829*9880d681SAndroid Build Coastguard Worker       unsigned Shift = 0;
830*9880d681SAndroid Build Coastguard Worker       do {
831*9880d681SAndroid Build Coastguard Worker         OS << ", " << (unsigned)*I;
832*9880d681SAndroid Build Coastguard Worker         Value += (*I & 0x7f) << Shift;
833*9880d681SAndroid Build Coastguard Worker         Shift += 7;
834*9880d681SAndroid Build Coastguard Worker       } while (*I++ >= 128);
835*9880d681SAndroid Build Coastguard Worker       if (Value > 127) {
836*9880d681SAndroid Build Coastguard Worker         OS << " /* 0x";
837*9880d681SAndroid Build Coastguard Worker         OS.write_hex(Value);
838*9880d681SAndroid Build Coastguard Worker         OS << " */";
839*9880d681SAndroid Build Coastguard Worker       }
840*9880d681SAndroid Build Coastguard Worker       // Negative mask
841*9880d681SAndroid Build Coastguard Worker       Value = 0;
842*9880d681SAndroid Build Coastguard Worker       Shift = 0;
843*9880d681SAndroid Build Coastguard Worker       do {
844*9880d681SAndroid Build Coastguard Worker         OS << ", " << (unsigned)*I;
845*9880d681SAndroid Build Coastguard Worker         Value += (*I & 0x7f) << Shift;
846*9880d681SAndroid Build Coastguard Worker         Shift += 7;
847*9880d681SAndroid Build Coastguard Worker       } while (*I++ >= 128);
848*9880d681SAndroid Build Coastguard Worker       if (Value > 127) {
849*9880d681SAndroid Build Coastguard Worker         OS << " /* 0x";
850*9880d681SAndroid Build Coastguard Worker         OS.write_hex(Value);
851*9880d681SAndroid Build Coastguard Worker         OS << " */";
852*9880d681SAndroid Build Coastguard Worker       }
853*9880d681SAndroid Build Coastguard Worker       OS << ",\n";
854*9880d681SAndroid Build Coastguard Worker       break;
855*9880d681SAndroid Build Coastguard Worker     }
856*9880d681SAndroid Build Coastguard Worker     case MCD::OPC_Fail: {
857*9880d681SAndroid Build Coastguard Worker       ++I;
858*9880d681SAndroid Build Coastguard Worker       OS.indent(Indentation) << "MCD::OPC_Fail,\n";
859*9880d681SAndroid Build Coastguard Worker       break;
860*9880d681SAndroid Build Coastguard Worker     }
861*9880d681SAndroid Build Coastguard Worker     }
862*9880d681SAndroid Build Coastguard Worker   }
863*9880d681SAndroid Build Coastguard Worker   OS.indent(Indentation) << "0\n";
864*9880d681SAndroid Build Coastguard Worker 
865*9880d681SAndroid Build Coastguard Worker   Indentation -= 2;
866*9880d681SAndroid Build Coastguard Worker 
867*9880d681SAndroid Build Coastguard Worker   OS.indent(Indentation) << "};\n\n";
868*9880d681SAndroid Build Coastguard Worker }
869*9880d681SAndroid Build Coastguard Worker 
870*9880d681SAndroid Build Coastguard Worker void FixedLenDecoderEmitter::
emitPredicateFunction(formatted_raw_ostream & OS,PredicateSet & Predicates,unsigned Indentation) const871*9880d681SAndroid Build Coastguard Worker emitPredicateFunction(formatted_raw_ostream &OS, PredicateSet &Predicates,
872*9880d681SAndroid Build Coastguard Worker                       unsigned Indentation) const {
873*9880d681SAndroid Build Coastguard Worker   // The predicate function is just a big switch statement based on the
874*9880d681SAndroid Build Coastguard Worker   // input predicate index.
875*9880d681SAndroid Build Coastguard Worker   OS.indent(Indentation) << "static bool checkDecoderPredicate(unsigned Idx, "
876*9880d681SAndroid Build Coastguard Worker     << "const FeatureBitset& Bits) {\n";
877*9880d681SAndroid Build Coastguard Worker   Indentation += 2;
878*9880d681SAndroid Build Coastguard Worker   if (!Predicates.empty()) {
879*9880d681SAndroid Build Coastguard Worker     OS.indent(Indentation) << "switch (Idx) {\n";
880*9880d681SAndroid Build Coastguard Worker     OS.indent(Indentation) << "default: llvm_unreachable(\"Invalid index!\");\n";
881*9880d681SAndroid Build Coastguard Worker     unsigned Index = 0;
882*9880d681SAndroid Build Coastguard Worker     for (const auto &Predicate : Predicates) {
883*9880d681SAndroid Build Coastguard Worker       OS.indent(Indentation) << "case " << Index++ << ":\n";
884*9880d681SAndroid Build Coastguard Worker       OS.indent(Indentation+2) << "return (" << Predicate << ");\n";
885*9880d681SAndroid Build Coastguard Worker     }
886*9880d681SAndroid Build Coastguard Worker     OS.indent(Indentation) << "}\n";
887*9880d681SAndroid Build Coastguard Worker   } else {
888*9880d681SAndroid Build Coastguard Worker     // No case statement to emit
889*9880d681SAndroid Build Coastguard Worker     OS.indent(Indentation) << "llvm_unreachable(\"Invalid index!\");\n";
890*9880d681SAndroid Build Coastguard Worker   }
891*9880d681SAndroid Build Coastguard Worker   Indentation -= 2;
892*9880d681SAndroid Build Coastguard Worker   OS.indent(Indentation) << "}\n\n";
893*9880d681SAndroid Build Coastguard Worker }
894*9880d681SAndroid Build Coastguard Worker 
895*9880d681SAndroid Build Coastguard Worker void FixedLenDecoderEmitter::
emitDecoderFunction(formatted_raw_ostream & OS,DecoderSet & Decoders,unsigned Indentation) const896*9880d681SAndroid Build Coastguard Worker emitDecoderFunction(formatted_raw_ostream &OS, DecoderSet &Decoders,
897*9880d681SAndroid Build Coastguard Worker                     unsigned Indentation) const {
898*9880d681SAndroid Build Coastguard Worker   // The decoder function is just a big switch statement based on the
899*9880d681SAndroid Build Coastguard Worker   // input decoder index.
900*9880d681SAndroid Build Coastguard Worker   OS.indent(Indentation) << "template<typename InsnType>\n";
901*9880d681SAndroid Build Coastguard Worker   OS.indent(Indentation) << "static DecodeStatus decodeToMCInst(DecodeStatus S,"
902*9880d681SAndroid Build Coastguard Worker     << " unsigned Idx, InsnType insn, MCInst &MI,\n";
903*9880d681SAndroid Build Coastguard Worker   OS.indent(Indentation) << "                                   uint64_t "
904*9880d681SAndroid Build Coastguard Worker     << "Address, const void *Decoder, bool &DecodeComplete) {\n";
905*9880d681SAndroid Build Coastguard Worker   Indentation += 2;
906*9880d681SAndroid Build Coastguard Worker   OS.indent(Indentation) << "DecodeComplete = true;\n";
907*9880d681SAndroid Build Coastguard Worker   OS.indent(Indentation) << "InsnType tmp;\n";
908*9880d681SAndroid Build Coastguard Worker   OS.indent(Indentation) << "switch (Idx) {\n";
909*9880d681SAndroid Build Coastguard Worker   OS.indent(Indentation) << "default: llvm_unreachable(\"Invalid index!\");\n";
910*9880d681SAndroid Build Coastguard Worker   unsigned Index = 0;
911*9880d681SAndroid Build Coastguard Worker   for (const auto &Decoder : Decoders) {
912*9880d681SAndroid Build Coastguard Worker     OS.indent(Indentation) << "case " << Index++ << ":\n";
913*9880d681SAndroid Build Coastguard Worker     OS << Decoder;
914*9880d681SAndroid Build Coastguard Worker     OS.indent(Indentation+2) << "return S;\n";
915*9880d681SAndroid Build Coastguard Worker   }
916*9880d681SAndroid Build Coastguard Worker   OS.indent(Indentation) << "}\n";
917*9880d681SAndroid Build Coastguard Worker   Indentation -= 2;
918*9880d681SAndroid Build Coastguard Worker   OS.indent(Indentation) << "}\n\n";
919*9880d681SAndroid Build Coastguard Worker }
920*9880d681SAndroid Build Coastguard Worker 
921*9880d681SAndroid Build Coastguard Worker // Populates the field of the insn given the start position and the number of
922*9880d681SAndroid Build Coastguard Worker // consecutive bits to scan for.
923*9880d681SAndroid Build Coastguard Worker //
924*9880d681SAndroid Build Coastguard Worker // Returns false if and on the first uninitialized bit value encountered.
925*9880d681SAndroid Build Coastguard Worker // Returns true, otherwise.
fieldFromInsn(uint64_t & Field,insn_t & Insn,unsigned StartBit,unsigned NumBits) const926*9880d681SAndroid Build Coastguard Worker bool FilterChooser::fieldFromInsn(uint64_t &Field, insn_t &Insn,
927*9880d681SAndroid Build Coastguard Worker                                   unsigned StartBit, unsigned NumBits) const {
928*9880d681SAndroid Build Coastguard Worker   Field = 0;
929*9880d681SAndroid Build Coastguard Worker 
930*9880d681SAndroid Build Coastguard Worker   for (unsigned i = 0; i < NumBits; ++i) {
931*9880d681SAndroid Build Coastguard Worker     if (Insn[StartBit + i] == BIT_UNSET)
932*9880d681SAndroid Build Coastguard Worker       return false;
933*9880d681SAndroid Build Coastguard Worker 
934*9880d681SAndroid Build Coastguard Worker     if (Insn[StartBit + i] == BIT_TRUE)
935*9880d681SAndroid Build Coastguard Worker       Field = Field | (1ULL << i);
936*9880d681SAndroid Build Coastguard Worker   }
937*9880d681SAndroid Build Coastguard Worker 
938*9880d681SAndroid Build Coastguard Worker   return true;
939*9880d681SAndroid Build Coastguard Worker }
940*9880d681SAndroid Build Coastguard Worker 
941*9880d681SAndroid Build Coastguard Worker /// dumpFilterArray - dumpFilterArray prints out debugging info for the given
942*9880d681SAndroid Build Coastguard Worker /// filter array as a series of chars.
dumpFilterArray(raw_ostream & o,const std::vector<bit_value_t> & filter) const943*9880d681SAndroid Build Coastguard Worker void FilterChooser::dumpFilterArray(raw_ostream &o,
944*9880d681SAndroid Build Coastguard Worker                                  const std::vector<bit_value_t> &filter) const {
945*9880d681SAndroid Build Coastguard Worker   for (unsigned bitIndex = BitWidth; bitIndex > 0; bitIndex--) {
946*9880d681SAndroid Build Coastguard Worker     switch (filter[bitIndex - 1]) {
947*9880d681SAndroid Build Coastguard Worker     case BIT_UNFILTERED:
948*9880d681SAndroid Build Coastguard Worker       o << ".";
949*9880d681SAndroid Build Coastguard Worker       break;
950*9880d681SAndroid Build Coastguard Worker     case BIT_UNSET:
951*9880d681SAndroid Build Coastguard Worker       o << "_";
952*9880d681SAndroid Build Coastguard Worker       break;
953*9880d681SAndroid Build Coastguard Worker     case BIT_TRUE:
954*9880d681SAndroid Build Coastguard Worker       o << "1";
955*9880d681SAndroid Build Coastguard Worker       break;
956*9880d681SAndroid Build Coastguard Worker     case BIT_FALSE:
957*9880d681SAndroid Build Coastguard Worker       o << "0";
958*9880d681SAndroid Build Coastguard Worker       break;
959*9880d681SAndroid Build Coastguard Worker     }
960*9880d681SAndroid Build Coastguard Worker   }
961*9880d681SAndroid Build Coastguard Worker }
962*9880d681SAndroid Build Coastguard Worker 
963*9880d681SAndroid Build Coastguard Worker /// dumpStack - dumpStack traverses the filter chooser chain and calls
964*9880d681SAndroid Build Coastguard Worker /// dumpFilterArray on each filter chooser up to the top level one.
dumpStack(raw_ostream & o,const char * prefix) const965*9880d681SAndroid Build Coastguard Worker void FilterChooser::dumpStack(raw_ostream &o, const char *prefix) const {
966*9880d681SAndroid Build Coastguard Worker   const FilterChooser *current = this;
967*9880d681SAndroid Build Coastguard Worker 
968*9880d681SAndroid Build Coastguard Worker   while (current) {
969*9880d681SAndroid Build Coastguard Worker     o << prefix;
970*9880d681SAndroid Build Coastguard Worker     dumpFilterArray(o, current->FilterBitValues);
971*9880d681SAndroid Build Coastguard Worker     o << '\n';
972*9880d681SAndroid Build Coastguard Worker     current = current->Parent;
973*9880d681SAndroid Build Coastguard Worker   }
974*9880d681SAndroid Build Coastguard Worker }
975*9880d681SAndroid Build Coastguard Worker 
976*9880d681SAndroid Build Coastguard Worker // Calculates the island(s) needed to decode the instruction.
977*9880d681SAndroid Build Coastguard Worker // This returns a list of undecoded bits of an instructions, for example,
978*9880d681SAndroid Build Coastguard Worker // Inst{20} = 1 && Inst{3-0} == 0b1111 represents two islands of yet-to-be
979*9880d681SAndroid Build Coastguard Worker // decoded bits in order to verify that the instruction matches the Opcode.
getIslands(std::vector<unsigned> & StartBits,std::vector<unsigned> & EndBits,std::vector<uint64_t> & FieldVals,const insn_t & Insn) const980*9880d681SAndroid Build Coastguard Worker unsigned FilterChooser::getIslands(std::vector<unsigned> &StartBits,
981*9880d681SAndroid Build Coastguard Worker                                    std::vector<unsigned> &EndBits,
982*9880d681SAndroid Build Coastguard Worker                                    std::vector<uint64_t> &FieldVals,
983*9880d681SAndroid Build Coastguard Worker                                    const insn_t &Insn) const {
984*9880d681SAndroid Build Coastguard Worker   unsigned Num, BitNo;
985*9880d681SAndroid Build Coastguard Worker   Num = BitNo = 0;
986*9880d681SAndroid Build Coastguard Worker 
987*9880d681SAndroid Build Coastguard Worker   uint64_t FieldVal = 0;
988*9880d681SAndroid Build Coastguard Worker 
989*9880d681SAndroid Build Coastguard Worker   // 0: Init
990*9880d681SAndroid Build Coastguard Worker   // 1: Water (the bit value does not affect decoding)
991*9880d681SAndroid Build Coastguard Worker   // 2: Island (well-known bit value needed for decoding)
992*9880d681SAndroid Build Coastguard Worker   int State = 0;
993*9880d681SAndroid Build Coastguard Worker   int Val = -1;
994*9880d681SAndroid Build Coastguard Worker 
995*9880d681SAndroid Build Coastguard Worker   for (unsigned i = 0; i < BitWidth; ++i) {
996*9880d681SAndroid Build Coastguard Worker     Val = Value(Insn[i]);
997*9880d681SAndroid Build Coastguard Worker     bool Filtered = PositionFiltered(i);
998*9880d681SAndroid Build Coastguard Worker     switch (State) {
999*9880d681SAndroid Build Coastguard Worker     default: llvm_unreachable("Unreachable code!");
1000*9880d681SAndroid Build Coastguard Worker     case 0:
1001*9880d681SAndroid Build Coastguard Worker     case 1:
1002*9880d681SAndroid Build Coastguard Worker       if (Filtered || Val == -1)
1003*9880d681SAndroid Build Coastguard Worker         State = 1; // Still in Water
1004*9880d681SAndroid Build Coastguard Worker       else {
1005*9880d681SAndroid Build Coastguard Worker         State = 2; // Into the Island
1006*9880d681SAndroid Build Coastguard Worker         BitNo = 0;
1007*9880d681SAndroid Build Coastguard Worker         StartBits.push_back(i);
1008*9880d681SAndroid Build Coastguard Worker         FieldVal = Val;
1009*9880d681SAndroid Build Coastguard Worker       }
1010*9880d681SAndroid Build Coastguard Worker       break;
1011*9880d681SAndroid Build Coastguard Worker     case 2:
1012*9880d681SAndroid Build Coastguard Worker       if (Filtered || Val == -1) {
1013*9880d681SAndroid Build Coastguard Worker         State = 1; // Into the Water
1014*9880d681SAndroid Build Coastguard Worker         EndBits.push_back(i - 1);
1015*9880d681SAndroid Build Coastguard Worker         FieldVals.push_back(FieldVal);
1016*9880d681SAndroid Build Coastguard Worker         ++Num;
1017*9880d681SAndroid Build Coastguard Worker       } else {
1018*9880d681SAndroid Build Coastguard Worker         State = 2; // Still in Island
1019*9880d681SAndroid Build Coastguard Worker         ++BitNo;
1020*9880d681SAndroid Build Coastguard Worker         FieldVal = FieldVal | Val << BitNo;
1021*9880d681SAndroid Build Coastguard Worker       }
1022*9880d681SAndroid Build Coastguard Worker       break;
1023*9880d681SAndroid Build Coastguard Worker     }
1024*9880d681SAndroid Build Coastguard Worker   }
1025*9880d681SAndroid Build Coastguard Worker   // If we are still in Island after the loop, do some housekeeping.
1026*9880d681SAndroid Build Coastguard Worker   if (State == 2) {
1027*9880d681SAndroid Build Coastguard Worker     EndBits.push_back(BitWidth - 1);
1028*9880d681SAndroid Build Coastguard Worker     FieldVals.push_back(FieldVal);
1029*9880d681SAndroid Build Coastguard Worker     ++Num;
1030*9880d681SAndroid Build Coastguard Worker   }
1031*9880d681SAndroid Build Coastguard Worker 
1032*9880d681SAndroid Build Coastguard Worker   assert(StartBits.size() == Num && EndBits.size() == Num &&
1033*9880d681SAndroid Build Coastguard Worker          FieldVals.size() == Num);
1034*9880d681SAndroid Build Coastguard Worker   return Num;
1035*9880d681SAndroid Build Coastguard Worker }
1036*9880d681SAndroid Build Coastguard Worker 
emitBinaryParser(raw_ostream & o,unsigned & Indentation,const OperandInfo & OpInfo,bool & OpHasCompleteDecoder) const1037*9880d681SAndroid Build Coastguard Worker void FilterChooser::emitBinaryParser(raw_ostream &o, unsigned &Indentation,
1038*9880d681SAndroid Build Coastguard Worker                                      const OperandInfo &OpInfo,
1039*9880d681SAndroid Build Coastguard Worker                                      bool &OpHasCompleteDecoder) const {
1040*9880d681SAndroid Build Coastguard Worker   const std::string &Decoder = OpInfo.Decoder;
1041*9880d681SAndroid Build Coastguard Worker 
1042*9880d681SAndroid Build Coastguard Worker   if (OpInfo.numFields() != 1)
1043*9880d681SAndroid Build Coastguard Worker     o.indent(Indentation) << "tmp = 0;\n";
1044*9880d681SAndroid Build Coastguard Worker 
1045*9880d681SAndroid Build Coastguard Worker   for (const EncodingField &EF : OpInfo) {
1046*9880d681SAndroid Build Coastguard Worker     o.indent(Indentation) << "tmp ";
1047*9880d681SAndroid Build Coastguard Worker     if (OpInfo.numFields() != 1) o << '|';
1048*9880d681SAndroid Build Coastguard Worker     o << "= fieldFromInstruction"
1049*9880d681SAndroid Build Coastguard Worker       << "(insn, " << EF.Base << ", " << EF.Width << ')';
1050*9880d681SAndroid Build Coastguard Worker     if (OpInfo.numFields() != 1 || EF.Offset != 0)
1051*9880d681SAndroid Build Coastguard Worker       o << " << " << EF.Offset;
1052*9880d681SAndroid Build Coastguard Worker     o << ";\n";
1053*9880d681SAndroid Build Coastguard Worker   }
1054*9880d681SAndroid Build Coastguard Worker 
1055*9880d681SAndroid Build Coastguard Worker   if (Decoder != "") {
1056*9880d681SAndroid Build Coastguard Worker     OpHasCompleteDecoder = OpInfo.HasCompleteDecoder;
1057*9880d681SAndroid Build Coastguard Worker     o.indent(Indentation) << Emitter->GuardPrefix << Decoder
1058*9880d681SAndroid Build Coastguard Worker       << "(MI, tmp, Address, Decoder)"
1059*9880d681SAndroid Build Coastguard Worker       << Emitter->GuardPostfix
1060*9880d681SAndroid Build Coastguard Worker       << " { " << (OpHasCompleteDecoder ? "" : "DecodeComplete = false; ")
1061*9880d681SAndroid Build Coastguard Worker       << "return MCDisassembler::Fail; }\n";
1062*9880d681SAndroid Build Coastguard Worker   } else {
1063*9880d681SAndroid Build Coastguard Worker     OpHasCompleteDecoder = true;
1064*9880d681SAndroid Build Coastguard Worker     o.indent(Indentation) << "MI.addOperand(MCOperand::createImm(tmp));\n";
1065*9880d681SAndroid Build Coastguard Worker   }
1066*9880d681SAndroid Build Coastguard Worker }
1067*9880d681SAndroid Build Coastguard Worker 
emitDecoder(raw_ostream & OS,unsigned Indentation,unsigned Opc,bool & HasCompleteDecoder) const1068*9880d681SAndroid Build Coastguard Worker void FilterChooser::emitDecoder(raw_ostream &OS, unsigned Indentation,
1069*9880d681SAndroid Build Coastguard Worker                                 unsigned Opc, bool &HasCompleteDecoder) const {
1070*9880d681SAndroid Build Coastguard Worker   HasCompleteDecoder = true;
1071*9880d681SAndroid Build Coastguard Worker 
1072*9880d681SAndroid Build Coastguard Worker   for (const auto &Op : Operands.find(Opc)->second) {
1073*9880d681SAndroid Build Coastguard Worker     // If a custom instruction decoder was specified, use that.
1074*9880d681SAndroid Build Coastguard Worker     if (Op.numFields() == 0 && Op.Decoder.size()) {
1075*9880d681SAndroid Build Coastguard Worker       HasCompleteDecoder = Op.HasCompleteDecoder;
1076*9880d681SAndroid Build Coastguard Worker       OS.indent(Indentation) << Emitter->GuardPrefix << Op.Decoder
1077*9880d681SAndroid Build Coastguard Worker         << "(MI, insn, Address, Decoder)"
1078*9880d681SAndroid Build Coastguard Worker         << Emitter->GuardPostfix
1079*9880d681SAndroid Build Coastguard Worker         << " { " << (HasCompleteDecoder ? "" : "DecodeComplete = false; ")
1080*9880d681SAndroid Build Coastguard Worker         << "return MCDisassembler::Fail; }\n";
1081*9880d681SAndroid Build Coastguard Worker       break;
1082*9880d681SAndroid Build Coastguard Worker     }
1083*9880d681SAndroid Build Coastguard Worker 
1084*9880d681SAndroid Build Coastguard Worker     bool OpHasCompleteDecoder;
1085*9880d681SAndroid Build Coastguard Worker     emitBinaryParser(OS, Indentation, Op, OpHasCompleteDecoder);
1086*9880d681SAndroid Build Coastguard Worker     if (!OpHasCompleteDecoder)
1087*9880d681SAndroid Build Coastguard Worker       HasCompleteDecoder = false;
1088*9880d681SAndroid Build Coastguard Worker   }
1089*9880d681SAndroid Build Coastguard Worker }
1090*9880d681SAndroid Build Coastguard Worker 
getDecoderIndex(DecoderSet & Decoders,unsigned Opc,bool & HasCompleteDecoder) const1091*9880d681SAndroid Build Coastguard Worker unsigned FilterChooser::getDecoderIndex(DecoderSet &Decoders,
1092*9880d681SAndroid Build Coastguard Worker                                         unsigned Opc,
1093*9880d681SAndroid Build Coastguard Worker                                         bool &HasCompleteDecoder) const {
1094*9880d681SAndroid Build Coastguard Worker   // Build up the predicate string.
1095*9880d681SAndroid Build Coastguard Worker   SmallString<256> Decoder;
1096*9880d681SAndroid Build Coastguard Worker   // FIXME: emitDecoder() function can take a buffer directly rather than
1097*9880d681SAndroid Build Coastguard Worker   // a stream.
1098*9880d681SAndroid Build Coastguard Worker   raw_svector_ostream S(Decoder);
1099*9880d681SAndroid Build Coastguard Worker   unsigned I = 4;
1100*9880d681SAndroid Build Coastguard Worker   emitDecoder(S, I, Opc, HasCompleteDecoder);
1101*9880d681SAndroid Build Coastguard Worker 
1102*9880d681SAndroid Build Coastguard Worker   // Using the full decoder string as the key value here is a bit
1103*9880d681SAndroid Build Coastguard Worker   // heavyweight, but is effective. If the string comparisons become a
1104*9880d681SAndroid Build Coastguard Worker   // performance concern, we can implement a mangling of the predicate
1105*9880d681SAndroid Build Coastguard Worker   // data easily enough with a map back to the actual string. That's
1106*9880d681SAndroid Build Coastguard Worker   // overkill for now, though.
1107*9880d681SAndroid Build Coastguard Worker 
1108*9880d681SAndroid Build Coastguard Worker   // Make sure the predicate is in the table.
1109*9880d681SAndroid Build Coastguard Worker   Decoders.insert(StringRef(Decoder));
1110*9880d681SAndroid Build Coastguard Worker   // Now figure out the index for when we write out the table.
1111*9880d681SAndroid Build Coastguard Worker   DecoderSet::const_iterator P = std::find(Decoders.begin(),
1112*9880d681SAndroid Build Coastguard Worker                                            Decoders.end(),
1113*9880d681SAndroid Build Coastguard Worker                                            Decoder.str());
1114*9880d681SAndroid Build Coastguard Worker   return (unsigned)(P - Decoders.begin());
1115*9880d681SAndroid Build Coastguard Worker }
1116*9880d681SAndroid Build Coastguard Worker 
emitSinglePredicateMatch(raw_ostream & o,StringRef str,const std::string & PredicateNamespace)1117*9880d681SAndroid Build Coastguard Worker static void emitSinglePredicateMatch(raw_ostream &o, StringRef str,
1118*9880d681SAndroid Build Coastguard Worker                                      const std::string &PredicateNamespace) {
1119*9880d681SAndroid Build Coastguard Worker   if (str[0] == '!')
1120*9880d681SAndroid Build Coastguard Worker     o << "!Bits[" << PredicateNamespace << "::"
1121*9880d681SAndroid Build Coastguard Worker       << str.slice(1,str.size()) << "]";
1122*9880d681SAndroid Build Coastguard Worker   else
1123*9880d681SAndroid Build Coastguard Worker     o << "Bits[" << PredicateNamespace << "::" << str << "]";
1124*9880d681SAndroid Build Coastguard Worker }
1125*9880d681SAndroid Build Coastguard Worker 
emitPredicateMatch(raw_ostream & o,unsigned & Indentation,unsigned Opc) const1126*9880d681SAndroid Build Coastguard Worker bool FilterChooser::emitPredicateMatch(raw_ostream &o, unsigned &Indentation,
1127*9880d681SAndroid Build Coastguard Worker                                        unsigned Opc) const {
1128*9880d681SAndroid Build Coastguard Worker   ListInit *Predicates =
1129*9880d681SAndroid Build Coastguard Worker     AllInstructions[Opc]->TheDef->getValueAsListInit("Predicates");
1130*9880d681SAndroid Build Coastguard Worker   bool IsFirstEmission = true;
1131*9880d681SAndroid Build Coastguard Worker   for (unsigned i = 0; i < Predicates->size(); ++i) {
1132*9880d681SAndroid Build Coastguard Worker     Record *Pred = Predicates->getElementAsRecord(i);
1133*9880d681SAndroid Build Coastguard Worker     if (!Pred->getValue("AssemblerMatcherPredicate"))
1134*9880d681SAndroid Build Coastguard Worker       continue;
1135*9880d681SAndroid Build Coastguard Worker 
1136*9880d681SAndroid Build Coastguard Worker     std::string P = Pred->getValueAsString("AssemblerCondString");
1137*9880d681SAndroid Build Coastguard Worker 
1138*9880d681SAndroid Build Coastguard Worker     if (!P.length())
1139*9880d681SAndroid Build Coastguard Worker       continue;
1140*9880d681SAndroid Build Coastguard Worker 
1141*9880d681SAndroid Build Coastguard Worker     if (!IsFirstEmission)
1142*9880d681SAndroid Build Coastguard Worker       o << " && ";
1143*9880d681SAndroid Build Coastguard Worker 
1144*9880d681SAndroid Build Coastguard Worker     StringRef SR(P);
1145*9880d681SAndroid Build Coastguard Worker     std::pair<StringRef, StringRef> pairs = SR.split(',');
1146*9880d681SAndroid Build Coastguard Worker     while (pairs.second.size()) {
1147*9880d681SAndroid Build Coastguard Worker       emitSinglePredicateMatch(o, pairs.first, Emitter->PredicateNamespace);
1148*9880d681SAndroid Build Coastguard Worker       o << " && ";
1149*9880d681SAndroid Build Coastguard Worker       pairs = pairs.second.split(',');
1150*9880d681SAndroid Build Coastguard Worker     }
1151*9880d681SAndroid Build Coastguard Worker     emitSinglePredicateMatch(o, pairs.first, Emitter->PredicateNamespace);
1152*9880d681SAndroid Build Coastguard Worker     IsFirstEmission = false;
1153*9880d681SAndroid Build Coastguard Worker   }
1154*9880d681SAndroid Build Coastguard Worker   return !Predicates->empty();
1155*9880d681SAndroid Build Coastguard Worker }
1156*9880d681SAndroid Build Coastguard Worker 
doesOpcodeNeedPredicate(unsigned Opc) const1157*9880d681SAndroid Build Coastguard Worker bool FilterChooser::doesOpcodeNeedPredicate(unsigned Opc) const {
1158*9880d681SAndroid Build Coastguard Worker   ListInit *Predicates =
1159*9880d681SAndroid Build Coastguard Worker     AllInstructions[Opc]->TheDef->getValueAsListInit("Predicates");
1160*9880d681SAndroid Build Coastguard Worker   for (unsigned i = 0; i < Predicates->size(); ++i) {
1161*9880d681SAndroid Build Coastguard Worker     Record *Pred = Predicates->getElementAsRecord(i);
1162*9880d681SAndroid Build Coastguard Worker     if (!Pred->getValue("AssemblerMatcherPredicate"))
1163*9880d681SAndroid Build Coastguard Worker       continue;
1164*9880d681SAndroid Build Coastguard Worker 
1165*9880d681SAndroid Build Coastguard Worker     std::string P = Pred->getValueAsString("AssemblerCondString");
1166*9880d681SAndroid Build Coastguard Worker 
1167*9880d681SAndroid Build Coastguard Worker     if (!P.length())
1168*9880d681SAndroid Build Coastguard Worker       continue;
1169*9880d681SAndroid Build Coastguard Worker 
1170*9880d681SAndroid Build Coastguard Worker     return true;
1171*9880d681SAndroid Build Coastguard Worker   }
1172*9880d681SAndroid Build Coastguard Worker   return false;
1173*9880d681SAndroid Build Coastguard Worker }
1174*9880d681SAndroid Build Coastguard Worker 
getPredicateIndex(DecoderTableInfo & TableInfo,StringRef Predicate) const1175*9880d681SAndroid Build Coastguard Worker unsigned FilterChooser::getPredicateIndex(DecoderTableInfo &TableInfo,
1176*9880d681SAndroid Build Coastguard Worker                                           StringRef Predicate) const {
1177*9880d681SAndroid Build Coastguard Worker   // Using the full predicate string as the key value here is a bit
1178*9880d681SAndroid Build Coastguard Worker   // heavyweight, but is effective. If the string comparisons become a
1179*9880d681SAndroid Build Coastguard Worker   // performance concern, we can implement a mangling of the predicate
1180*9880d681SAndroid Build Coastguard Worker   // data easily enough with a map back to the actual string. That's
1181*9880d681SAndroid Build Coastguard Worker   // overkill for now, though.
1182*9880d681SAndroid Build Coastguard Worker 
1183*9880d681SAndroid Build Coastguard Worker   // Make sure the predicate is in the table.
1184*9880d681SAndroid Build Coastguard Worker   TableInfo.Predicates.insert(Predicate.str());
1185*9880d681SAndroid Build Coastguard Worker   // Now figure out the index for when we write out the table.
1186*9880d681SAndroid Build Coastguard Worker   PredicateSet::const_iterator P = std::find(TableInfo.Predicates.begin(),
1187*9880d681SAndroid Build Coastguard Worker                                              TableInfo.Predicates.end(),
1188*9880d681SAndroid Build Coastguard Worker                                              Predicate.str());
1189*9880d681SAndroid Build Coastguard Worker   return (unsigned)(P - TableInfo.Predicates.begin());
1190*9880d681SAndroid Build Coastguard Worker }
1191*9880d681SAndroid Build Coastguard Worker 
emitPredicateTableEntry(DecoderTableInfo & TableInfo,unsigned Opc) const1192*9880d681SAndroid Build Coastguard Worker void FilterChooser::emitPredicateTableEntry(DecoderTableInfo &TableInfo,
1193*9880d681SAndroid Build Coastguard Worker                                             unsigned Opc) const {
1194*9880d681SAndroid Build Coastguard Worker   if (!doesOpcodeNeedPredicate(Opc))
1195*9880d681SAndroid Build Coastguard Worker     return;
1196*9880d681SAndroid Build Coastguard Worker 
1197*9880d681SAndroid Build Coastguard Worker   // Build up the predicate string.
1198*9880d681SAndroid Build Coastguard Worker   SmallString<256> Predicate;
1199*9880d681SAndroid Build Coastguard Worker   // FIXME: emitPredicateMatch() functions can take a buffer directly rather
1200*9880d681SAndroid Build Coastguard Worker   // than a stream.
1201*9880d681SAndroid Build Coastguard Worker   raw_svector_ostream PS(Predicate);
1202*9880d681SAndroid Build Coastguard Worker   unsigned I = 0;
1203*9880d681SAndroid Build Coastguard Worker   emitPredicateMatch(PS, I, Opc);
1204*9880d681SAndroid Build Coastguard Worker 
1205*9880d681SAndroid Build Coastguard Worker   // Figure out the index into the predicate table for the predicate just
1206*9880d681SAndroid Build Coastguard Worker   // computed.
1207*9880d681SAndroid Build Coastguard Worker   unsigned PIdx = getPredicateIndex(TableInfo, PS.str());
1208*9880d681SAndroid Build Coastguard Worker   SmallString<16> PBytes;
1209*9880d681SAndroid Build Coastguard Worker   raw_svector_ostream S(PBytes);
1210*9880d681SAndroid Build Coastguard Worker   encodeULEB128(PIdx, S);
1211*9880d681SAndroid Build Coastguard Worker 
1212*9880d681SAndroid Build Coastguard Worker   TableInfo.Table.push_back(MCD::OPC_CheckPredicate);
1213*9880d681SAndroid Build Coastguard Worker   // Predicate index
1214*9880d681SAndroid Build Coastguard Worker   for (unsigned i = 0, e = PBytes.size(); i != e; ++i)
1215*9880d681SAndroid Build Coastguard Worker     TableInfo.Table.push_back(PBytes[i]);
1216*9880d681SAndroid Build Coastguard Worker   // Push location for NumToSkip backpatching.
1217*9880d681SAndroid Build Coastguard Worker   TableInfo.FixupStack.back().push_back(TableInfo.Table.size());
1218*9880d681SAndroid Build Coastguard Worker   TableInfo.Table.push_back(0);
1219*9880d681SAndroid Build Coastguard Worker   TableInfo.Table.push_back(0);
1220*9880d681SAndroid Build Coastguard Worker }
1221*9880d681SAndroid Build Coastguard Worker 
emitSoftFailTableEntry(DecoderTableInfo & TableInfo,unsigned Opc) const1222*9880d681SAndroid Build Coastguard Worker void FilterChooser::emitSoftFailTableEntry(DecoderTableInfo &TableInfo,
1223*9880d681SAndroid Build Coastguard Worker                                            unsigned Opc) const {
1224*9880d681SAndroid Build Coastguard Worker   BitsInit *SFBits =
1225*9880d681SAndroid Build Coastguard Worker     AllInstructions[Opc]->TheDef->getValueAsBitsInit("SoftFail");
1226*9880d681SAndroid Build Coastguard Worker   if (!SFBits) return;
1227*9880d681SAndroid Build Coastguard Worker   BitsInit *InstBits = AllInstructions[Opc]->TheDef->getValueAsBitsInit("Inst");
1228*9880d681SAndroid Build Coastguard Worker 
1229*9880d681SAndroid Build Coastguard Worker   APInt PositiveMask(BitWidth, 0ULL);
1230*9880d681SAndroid Build Coastguard Worker   APInt NegativeMask(BitWidth, 0ULL);
1231*9880d681SAndroid Build Coastguard Worker   for (unsigned i = 0; i < BitWidth; ++i) {
1232*9880d681SAndroid Build Coastguard Worker     bit_value_t B = bitFromBits(*SFBits, i);
1233*9880d681SAndroid Build Coastguard Worker     bit_value_t IB = bitFromBits(*InstBits, i);
1234*9880d681SAndroid Build Coastguard Worker 
1235*9880d681SAndroid Build Coastguard Worker     if (B != BIT_TRUE) continue;
1236*9880d681SAndroid Build Coastguard Worker 
1237*9880d681SAndroid Build Coastguard Worker     switch (IB) {
1238*9880d681SAndroid Build Coastguard Worker     case BIT_FALSE:
1239*9880d681SAndroid Build Coastguard Worker       // The bit is meant to be false, so emit a check to see if it is true.
1240*9880d681SAndroid Build Coastguard Worker       PositiveMask.setBit(i);
1241*9880d681SAndroid Build Coastguard Worker       break;
1242*9880d681SAndroid Build Coastguard Worker     case BIT_TRUE:
1243*9880d681SAndroid Build Coastguard Worker       // The bit is meant to be true, so emit a check to see if it is false.
1244*9880d681SAndroid Build Coastguard Worker       NegativeMask.setBit(i);
1245*9880d681SAndroid Build Coastguard Worker       break;
1246*9880d681SAndroid Build Coastguard Worker     default:
1247*9880d681SAndroid Build Coastguard Worker       // The bit is not set; this must be an error!
1248*9880d681SAndroid Build Coastguard Worker       StringRef Name = AllInstructions[Opc]->TheDef->getName();
1249*9880d681SAndroid Build Coastguard Worker       errs() << "SoftFail Conflict: bit SoftFail{" << i << "} in " << Name
1250*9880d681SAndroid Build Coastguard Worker              << " is set but Inst{" << i << "} is unset!\n"
1251*9880d681SAndroid Build Coastguard Worker              << "  - You can only mark a bit as SoftFail if it is fully defined"
1252*9880d681SAndroid Build Coastguard Worker              << " (1/0 - not '?') in Inst\n";
1253*9880d681SAndroid Build Coastguard Worker       return;
1254*9880d681SAndroid Build Coastguard Worker     }
1255*9880d681SAndroid Build Coastguard Worker   }
1256*9880d681SAndroid Build Coastguard Worker 
1257*9880d681SAndroid Build Coastguard Worker   bool NeedPositiveMask = PositiveMask.getBoolValue();
1258*9880d681SAndroid Build Coastguard Worker   bool NeedNegativeMask = NegativeMask.getBoolValue();
1259*9880d681SAndroid Build Coastguard Worker 
1260*9880d681SAndroid Build Coastguard Worker   if (!NeedPositiveMask && !NeedNegativeMask)
1261*9880d681SAndroid Build Coastguard Worker     return;
1262*9880d681SAndroid Build Coastguard Worker 
1263*9880d681SAndroid Build Coastguard Worker   TableInfo.Table.push_back(MCD::OPC_SoftFail);
1264*9880d681SAndroid Build Coastguard Worker 
1265*9880d681SAndroid Build Coastguard Worker   SmallString<16> MaskBytes;
1266*9880d681SAndroid Build Coastguard Worker   raw_svector_ostream S(MaskBytes);
1267*9880d681SAndroid Build Coastguard Worker   if (NeedPositiveMask) {
1268*9880d681SAndroid Build Coastguard Worker     encodeULEB128(PositiveMask.getZExtValue(), S);
1269*9880d681SAndroid Build Coastguard Worker     for (unsigned i = 0, e = MaskBytes.size(); i != e; ++i)
1270*9880d681SAndroid Build Coastguard Worker       TableInfo.Table.push_back(MaskBytes[i]);
1271*9880d681SAndroid Build Coastguard Worker   } else
1272*9880d681SAndroid Build Coastguard Worker     TableInfo.Table.push_back(0);
1273*9880d681SAndroid Build Coastguard Worker   if (NeedNegativeMask) {
1274*9880d681SAndroid Build Coastguard Worker     MaskBytes.clear();
1275*9880d681SAndroid Build Coastguard Worker     encodeULEB128(NegativeMask.getZExtValue(), S);
1276*9880d681SAndroid Build Coastguard Worker     for (unsigned i = 0, e = MaskBytes.size(); i != e; ++i)
1277*9880d681SAndroid Build Coastguard Worker       TableInfo.Table.push_back(MaskBytes[i]);
1278*9880d681SAndroid Build Coastguard Worker   } else
1279*9880d681SAndroid Build Coastguard Worker     TableInfo.Table.push_back(0);
1280*9880d681SAndroid Build Coastguard Worker }
1281*9880d681SAndroid Build Coastguard Worker 
1282*9880d681SAndroid Build Coastguard Worker // Emits table entries to decode the singleton.
emitSingletonTableEntry(DecoderTableInfo & TableInfo,unsigned Opc) const1283*9880d681SAndroid Build Coastguard Worker void FilterChooser::emitSingletonTableEntry(DecoderTableInfo &TableInfo,
1284*9880d681SAndroid Build Coastguard Worker                                             unsigned Opc) const {
1285*9880d681SAndroid Build Coastguard Worker   std::vector<unsigned> StartBits;
1286*9880d681SAndroid Build Coastguard Worker   std::vector<unsigned> EndBits;
1287*9880d681SAndroid Build Coastguard Worker   std::vector<uint64_t> FieldVals;
1288*9880d681SAndroid Build Coastguard Worker   insn_t Insn;
1289*9880d681SAndroid Build Coastguard Worker   insnWithID(Insn, Opc);
1290*9880d681SAndroid Build Coastguard Worker 
1291*9880d681SAndroid Build Coastguard Worker   // Look for islands of undecoded bits of the singleton.
1292*9880d681SAndroid Build Coastguard Worker   getIslands(StartBits, EndBits, FieldVals, Insn);
1293*9880d681SAndroid Build Coastguard Worker 
1294*9880d681SAndroid Build Coastguard Worker   unsigned Size = StartBits.size();
1295*9880d681SAndroid Build Coastguard Worker 
1296*9880d681SAndroid Build Coastguard Worker   // Emit the predicate table entry if one is needed.
1297*9880d681SAndroid Build Coastguard Worker   emitPredicateTableEntry(TableInfo, Opc);
1298*9880d681SAndroid Build Coastguard Worker 
1299*9880d681SAndroid Build Coastguard Worker   // Check any additional encoding fields needed.
1300*9880d681SAndroid Build Coastguard Worker   for (unsigned I = Size; I != 0; --I) {
1301*9880d681SAndroid Build Coastguard Worker     unsigned NumBits = EndBits[I-1] - StartBits[I-1] + 1;
1302*9880d681SAndroid Build Coastguard Worker     TableInfo.Table.push_back(MCD::OPC_CheckField);
1303*9880d681SAndroid Build Coastguard Worker     TableInfo.Table.push_back(StartBits[I-1]);
1304*9880d681SAndroid Build Coastguard Worker     TableInfo.Table.push_back(NumBits);
1305*9880d681SAndroid Build Coastguard Worker     uint8_t Buffer[8], *p;
1306*9880d681SAndroid Build Coastguard Worker     encodeULEB128(FieldVals[I-1], Buffer);
1307*9880d681SAndroid Build Coastguard Worker     for (p = Buffer; *p >= 128 ; ++p)
1308*9880d681SAndroid Build Coastguard Worker       TableInfo.Table.push_back(*p);
1309*9880d681SAndroid Build Coastguard Worker     TableInfo.Table.push_back(*p);
1310*9880d681SAndroid Build Coastguard Worker     // Push location for NumToSkip backpatching.
1311*9880d681SAndroid Build Coastguard Worker     TableInfo.FixupStack.back().push_back(TableInfo.Table.size());
1312*9880d681SAndroid Build Coastguard Worker     // The fixup is always 16-bits, so go ahead and allocate the space
1313*9880d681SAndroid Build Coastguard Worker     // in the table so all our relative position calculations work OK even
1314*9880d681SAndroid Build Coastguard Worker     // before we fully resolve the real value here.
1315*9880d681SAndroid Build Coastguard Worker     TableInfo.Table.push_back(0);
1316*9880d681SAndroid Build Coastguard Worker     TableInfo.Table.push_back(0);
1317*9880d681SAndroid Build Coastguard Worker   }
1318*9880d681SAndroid Build Coastguard Worker 
1319*9880d681SAndroid Build Coastguard Worker   // Check for soft failure of the match.
1320*9880d681SAndroid Build Coastguard Worker   emitSoftFailTableEntry(TableInfo, Opc);
1321*9880d681SAndroid Build Coastguard Worker 
1322*9880d681SAndroid Build Coastguard Worker   bool HasCompleteDecoder;
1323*9880d681SAndroid Build Coastguard Worker   unsigned DIdx = getDecoderIndex(TableInfo.Decoders, Opc, HasCompleteDecoder);
1324*9880d681SAndroid Build Coastguard Worker 
1325*9880d681SAndroid Build Coastguard Worker   // Produce OPC_Decode or OPC_TryDecode opcode based on the information
1326*9880d681SAndroid Build Coastguard Worker   // whether the instruction decoder is complete or not. If it is complete
1327*9880d681SAndroid Build Coastguard Worker   // then it handles all possible values of remaining variable/unfiltered bits
1328*9880d681SAndroid Build Coastguard Worker   // and for any value can determine if the bitpattern is a valid instruction
1329*9880d681SAndroid Build Coastguard Worker   // or not. This means OPC_Decode will be the final step in the decoding
1330*9880d681SAndroid Build Coastguard Worker   // process. If it is not complete, then the Fail return code from the
1331*9880d681SAndroid Build Coastguard Worker   // decoder method indicates that additional processing should be done to see
1332*9880d681SAndroid Build Coastguard Worker   // if there is any other instruction that also matches the bitpattern and
1333*9880d681SAndroid Build Coastguard Worker   // can decode it.
1334*9880d681SAndroid Build Coastguard Worker   TableInfo.Table.push_back(HasCompleteDecoder ? MCD::OPC_Decode :
1335*9880d681SAndroid Build Coastguard Worker       MCD::OPC_TryDecode);
1336*9880d681SAndroid Build Coastguard Worker   uint8_t Buffer[8], *p;
1337*9880d681SAndroid Build Coastguard Worker   encodeULEB128(Opc, Buffer);
1338*9880d681SAndroid Build Coastguard Worker   for (p = Buffer; *p >= 128 ; ++p)
1339*9880d681SAndroid Build Coastguard Worker     TableInfo.Table.push_back(*p);
1340*9880d681SAndroid Build Coastguard Worker   TableInfo.Table.push_back(*p);
1341*9880d681SAndroid Build Coastguard Worker 
1342*9880d681SAndroid Build Coastguard Worker   SmallString<16> Bytes;
1343*9880d681SAndroid Build Coastguard Worker   raw_svector_ostream S(Bytes);
1344*9880d681SAndroid Build Coastguard Worker   encodeULEB128(DIdx, S);
1345*9880d681SAndroid Build Coastguard Worker 
1346*9880d681SAndroid Build Coastguard Worker   // Decoder index
1347*9880d681SAndroid Build Coastguard Worker   for (unsigned i = 0, e = Bytes.size(); i != e; ++i)
1348*9880d681SAndroid Build Coastguard Worker     TableInfo.Table.push_back(Bytes[i]);
1349*9880d681SAndroid Build Coastguard Worker 
1350*9880d681SAndroid Build Coastguard Worker   if (!HasCompleteDecoder) {
1351*9880d681SAndroid Build Coastguard Worker     // Push location for NumToSkip backpatching.
1352*9880d681SAndroid Build Coastguard Worker     TableInfo.FixupStack.back().push_back(TableInfo.Table.size());
1353*9880d681SAndroid Build Coastguard Worker     // Allocate the space for the fixup.
1354*9880d681SAndroid Build Coastguard Worker     TableInfo.Table.push_back(0);
1355*9880d681SAndroid Build Coastguard Worker     TableInfo.Table.push_back(0);
1356*9880d681SAndroid Build Coastguard Worker   }
1357*9880d681SAndroid Build Coastguard Worker }
1358*9880d681SAndroid Build Coastguard Worker 
1359*9880d681SAndroid Build Coastguard Worker // Emits table entries to decode the singleton, and then to decode the rest.
emitSingletonTableEntry(DecoderTableInfo & TableInfo,const Filter & Best) const1360*9880d681SAndroid Build Coastguard Worker void FilterChooser::emitSingletonTableEntry(DecoderTableInfo &TableInfo,
1361*9880d681SAndroid Build Coastguard Worker                                             const Filter &Best) const {
1362*9880d681SAndroid Build Coastguard Worker   unsigned Opc = Best.getSingletonOpc();
1363*9880d681SAndroid Build Coastguard Worker 
1364*9880d681SAndroid Build Coastguard Worker   // complex singletons need predicate checks from the first singleton
1365*9880d681SAndroid Build Coastguard Worker   // to refer forward to the variable filterchooser that follows.
1366*9880d681SAndroid Build Coastguard Worker   TableInfo.FixupStack.emplace_back();
1367*9880d681SAndroid Build Coastguard Worker 
1368*9880d681SAndroid Build Coastguard Worker   emitSingletonTableEntry(TableInfo, Opc);
1369*9880d681SAndroid Build Coastguard Worker 
1370*9880d681SAndroid Build Coastguard Worker   resolveTableFixups(TableInfo.Table, TableInfo.FixupStack.back(),
1371*9880d681SAndroid Build Coastguard Worker                      TableInfo.Table.size());
1372*9880d681SAndroid Build Coastguard Worker   TableInfo.FixupStack.pop_back();
1373*9880d681SAndroid Build Coastguard Worker 
1374*9880d681SAndroid Build Coastguard Worker   Best.getVariableFC().emitTableEntries(TableInfo);
1375*9880d681SAndroid Build Coastguard Worker }
1376*9880d681SAndroid Build Coastguard Worker 
1377*9880d681SAndroid Build Coastguard Worker 
1378*9880d681SAndroid Build Coastguard Worker // Assign a single filter and run with it.  Top level API client can initialize
1379*9880d681SAndroid Build Coastguard Worker // with a single filter to start the filtering process.
runSingleFilter(unsigned startBit,unsigned numBit,bool mixed)1380*9880d681SAndroid Build Coastguard Worker void FilterChooser::runSingleFilter(unsigned startBit, unsigned numBit,
1381*9880d681SAndroid Build Coastguard Worker                                     bool mixed) {
1382*9880d681SAndroid Build Coastguard Worker   Filters.clear();
1383*9880d681SAndroid Build Coastguard Worker   Filters.emplace_back(*this, startBit, numBit, true);
1384*9880d681SAndroid Build Coastguard Worker   BestIndex = 0; // Sole Filter instance to choose from.
1385*9880d681SAndroid Build Coastguard Worker   bestFilter().recurse();
1386*9880d681SAndroid Build Coastguard Worker }
1387*9880d681SAndroid Build Coastguard Worker 
1388*9880d681SAndroid Build Coastguard Worker // reportRegion is a helper function for filterProcessor to mark a region as
1389*9880d681SAndroid Build Coastguard Worker // eligible for use as a filter region.
reportRegion(bitAttr_t RA,unsigned StartBit,unsigned BitIndex,bool AllowMixed)1390*9880d681SAndroid Build Coastguard Worker void FilterChooser::reportRegion(bitAttr_t RA, unsigned StartBit,
1391*9880d681SAndroid Build Coastguard Worker                                  unsigned BitIndex, bool AllowMixed) {
1392*9880d681SAndroid Build Coastguard Worker   if (RA == ATTR_MIXED && AllowMixed)
1393*9880d681SAndroid Build Coastguard Worker     Filters.emplace_back(*this, StartBit, BitIndex - StartBit, true);
1394*9880d681SAndroid Build Coastguard Worker   else if (RA == ATTR_ALL_SET && !AllowMixed)
1395*9880d681SAndroid Build Coastguard Worker     Filters.emplace_back(*this, StartBit, BitIndex - StartBit, false);
1396*9880d681SAndroid Build Coastguard Worker }
1397*9880d681SAndroid Build Coastguard Worker 
1398*9880d681SAndroid Build Coastguard Worker // FilterProcessor scans the well-known encoding bits of the instructions and
1399*9880d681SAndroid Build Coastguard Worker // builds up a list of candidate filters.  It chooses the best filter and
1400*9880d681SAndroid Build Coastguard Worker // recursively descends down the decoding tree.
filterProcessor(bool AllowMixed,bool Greedy)1401*9880d681SAndroid Build Coastguard Worker bool FilterChooser::filterProcessor(bool AllowMixed, bool Greedy) {
1402*9880d681SAndroid Build Coastguard Worker   Filters.clear();
1403*9880d681SAndroid Build Coastguard Worker   BestIndex = -1;
1404*9880d681SAndroid Build Coastguard Worker   unsigned numInstructions = Opcodes.size();
1405*9880d681SAndroid Build Coastguard Worker 
1406*9880d681SAndroid Build Coastguard Worker   assert(numInstructions && "Filter created with no instructions");
1407*9880d681SAndroid Build Coastguard Worker 
1408*9880d681SAndroid Build Coastguard Worker   // No further filtering is necessary.
1409*9880d681SAndroid Build Coastguard Worker   if (numInstructions == 1)
1410*9880d681SAndroid Build Coastguard Worker     return true;
1411*9880d681SAndroid Build Coastguard Worker 
1412*9880d681SAndroid Build Coastguard Worker   // Heuristics.  See also doFilter()'s "Heuristics" comment when num of
1413*9880d681SAndroid Build Coastguard Worker   // instructions is 3.
1414*9880d681SAndroid Build Coastguard Worker   if (AllowMixed && !Greedy) {
1415*9880d681SAndroid Build Coastguard Worker     assert(numInstructions == 3);
1416*9880d681SAndroid Build Coastguard Worker 
1417*9880d681SAndroid Build Coastguard Worker     for (unsigned i = 0; i < Opcodes.size(); ++i) {
1418*9880d681SAndroid Build Coastguard Worker       std::vector<unsigned> StartBits;
1419*9880d681SAndroid Build Coastguard Worker       std::vector<unsigned> EndBits;
1420*9880d681SAndroid Build Coastguard Worker       std::vector<uint64_t> FieldVals;
1421*9880d681SAndroid Build Coastguard Worker       insn_t Insn;
1422*9880d681SAndroid Build Coastguard Worker 
1423*9880d681SAndroid Build Coastguard Worker       insnWithID(Insn, Opcodes[i]);
1424*9880d681SAndroid Build Coastguard Worker 
1425*9880d681SAndroid Build Coastguard Worker       // Look for islands of undecoded bits of any instruction.
1426*9880d681SAndroid Build Coastguard Worker       if (getIslands(StartBits, EndBits, FieldVals, Insn) > 0) {
1427*9880d681SAndroid Build Coastguard Worker         // Found an instruction with island(s).  Now just assign a filter.
1428*9880d681SAndroid Build Coastguard Worker         runSingleFilter(StartBits[0], EndBits[0] - StartBits[0] + 1, true);
1429*9880d681SAndroid Build Coastguard Worker         return true;
1430*9880d681SAndroid Build Coastguard Worker       }
1431*9880d681SAndroid Build Coastguard Worker     }
1432*9880d681SAndroid Build Coastguard Worker   }
1433*9880d681SAndroid Build Coastguard Worker 
1434*9880d681SAndroid Build Coastguard Worker   unsigned BitIndex;
1435*9880d681SAndroid Build Coastguard Worker 
1436*9880d681SAndroid Build Coastguard Worker   // We maintain BIT_WIDTH copies of the bitAttrs automaton.
1437*9880d681SAndroid Build Coastguard Worker   // The automaton consumes the corresponding bit from each
1438*9880d681SAndroid Build Coastguard Worker   // instruction.
1439*9880d681SAndroid Build Coastguard Worker   //
1440*9880d681SAndroid Build Coastguard Worker   //   Input symbols: 0, 1, and _ (unset).
1441*9880d681SAndroid Build Coastguard Worker   //   States:        NONE, FILTERED, ALL_SET, ALL_UNSET, and MIXED.
1442*9880d681SAndroid Build Coastguard Worker   //   Initial state: NONE.
1443*9880d681SAndroid Build Coastguard Worker   //
1444*9880d681SAndroid Build Coastguard Worker   // (NONE) ------- [01] -> (ALL_SET)
1445*9880d681SAndroid Build Coastguard Worker   // (NONE) ------- _ ----> (ALL_UNSET)
1446*9880d681SAndroid Build Coastguard Worker   // (ALL_SET) ---- [01] -> (ALL_SET)
1447*9880d681SAndroid Build Coastguard Worker   // (ALL_SET) ---- _ ----> (MIXED)
1448*9880d681SAndroid Build Coastguard Worker   // (ALL_UNSET) -- [01] -> (MIXED)
1449*9880d681SAndroid Build Coastguard Worker   // (ALL_UNSET) -- _ ----> (ALL_UNSET)
1450*9880d681SAndroid Build Coastguard Worker   // (MIXED) ------ . ----> (MIXED)
1451*9880d681SAndroid Build Coastguard Worker   // (FILTERED)---- . ----> (FILTERED)
1452*9880d681SAndroid Build Coastguard Worker 
1453*9880d681SAndroid Build Coastguard Worker   std::vector<bitAttr_t> bitAttrs;
1454*9880d681SAndroid Build Coastguard Worker 
1455*9880d681SAndroid Build Coastguard Worker   // FILTERED bit positions provide no entropy and are not worthy of pursuing.
1456*9880d681SAndroid Build Coastguard Worker   // Filter::recurse() set either BIT_TRUE or BIT_FALSE for each position.
1457*9880d681SAndroid Build Coastguard Worker   for (BitIndex = 0; BitIndex < BitWidth; ++BitIndex)
1458*9880d681SAndroid Build Coastguard Worker     if (FilterBitValues[BitIndex] == BIT_TRUE ||
1459*9880d681SAndroid Build Coastguard Worker         FilterBitValues[BitIndex] == BIT_FALSE)
1460*9880d681SAndroid Build Coastguard Worker       bitAttrs.push_back(ATTR_FILTERED);
1461*9880d681SAndroid Build Coastguard Worker     else
1462*9880d681SAndroid Build Coastguard Worker       bitAttrs.push_back(ATTR_NONE);
1463*9880d681SAndroid Build Coastguard Worker 
1464*9880d681SAndroid Build Coastguard Worker   for (unsigned InsnIndex = 0; InsnIndex < numInstructions; ++InsnIndex) {
1465*9880d681SAndroid Build Coastguard Worker     insn_t insn;
1466*9880d681SAndroid Build Coastguard Worker 
1467*9880d681SAndroid Build Coastguard Worker     insnWithID(insn, Opcodes[InsnIndex]);
1468*9880d681SAndroid Build Coastguard Worker 
1469*9880d681SAndroid Build Coastguard Worker     for (BitIndex = 0; BitIndex < BitWidth; ++BitIndex) {
1470*9880d681SAndroid Build Coastguard Worker       switch (bitAttrs[BitIndex]) {
1471*9880d681SAndroid Build Coastguard Worker       case ATTR_NONE:
1472*9880d681SAndroid Build Coastguard Worker         if (insn[BitIndex] == BIT_UNSET)
1473*9880d681SAndroid Build Coastguard Worker           bitAttrs[BitIndex] = ATTR_ALL_UNSET;
1474*9880d681SAndroid Build Coastguard Worker         else
1475*9880d681SAndroid Build Coastguard Worker           bitAttrs[BitIndex] = ATTR_ALL_SET;
1476*9880d681SAndroid Build Coastguard Worker         break;
1477*9880d681SAndroid Build Coastguard Worker       case ATTR_ALL_SET:
1478*9880d681SAndroid Build Coastguard Worker         if (insn[BitIndex] == BIT_UNSET)
1479*9880d681SAndroid Build Coastguard Worker           bitAttrs[BitIndex] = ATTR_MIXED;
1480*9880d681SAndroid Build Coastguard Worker         break;
1481*9880d681SAndroid Build Coastguard Worker       case ATTR_ALL_UNSET:
1482*9880d681SAndroid Build Coastguard Worker         if (insn[BitIndex] != BIT_UNSET)
1483*9880d681SAndroid Build Coastguard Worker           bitAttrs[BitIndex] = ATTR_MIXED;
1484*9880d681SAndroid Build Coastguard Worker         break;
1485*9880d681SAndroid Build Coastguard Worker       case ATTR_MIXED:
1486*9880d681SAndroid Build Coastguard Worker       case ATTR_FILTERED:
1487*9880d681SAndroid Build Coastguard Worker         break;
1488*9880d681SAndroid Build Coastguard Worker       }
1489*9880d681SAndroid Build Coastguard Worker     }
1490*9880d681SAndroid Build Coastguard Worker   }
1491*9880d681SAndroid Build Coastguard Worker 
1492*9880d681SAndroid Build Coastguard Worker   // The regionAttr automaton consumes the bitAttrs automatons' state,
1493*9880d681SAndroid Build Coastguard Worker   // lowest-to-highest.
1494*9880d681SAndroid Build Coastguard Worker   //
1495*9880d681SAndroid Build Coastguard Worker   //   Input symbols: F(iltered), (all_)S(et), (all_)U(nset), M(ixed)
1496*9880d681SAndroid Build Coastguard Worker   //   States:        NONE, ALL_SET, MIXED
1497*9880d681SAndroid Build Coastguard Worker   //   Initial state: NONE
1498*9880d681SAndroid Build Coastguard Worker   //
1499*9880d681SAndroid Build Coastguard Worker   // (NONE) ----- F --> (NONE)
1500*9880d681SAndroid Build Coastguard Worker   // (NONE) ----- S --> (ALL_SET)     ; and set region start
1501*9880d681SAndroid Build Coastguard Worker   // (NONE) ----- U --> (NONE)
1502*9880d681SAndroid Build Coastguard Worker   // (NONE) ----- M --> (MIXED)       ; and set region start
1503*9880d681SAndroid Build Coastguard Worker   // (ALL_SET) -- F --> (NONE)        ; and report an ALL_SET region
1504*9880d681SAndroid Build Coastguard Worker   // (ALL_SET) -- S --> (ALL_SET)
1505*9880d681SAndroid Build Coastguard Worker   // (ALL_SET) -- U --> (NONE)        ; and report an ALL_SET region
1506*9880d681SAndroid Build Coastguard Worker   // (ALL_SET) -- M --> (MIXED)       ; and report an ALL_SET region
1507*9880d681SAndroid Build Coastguard Worker   // (MIXED) ---- F --> (NONE)        ; and report a MIXED region
1508*9880d681SAndroid Build Coastguard Worker   // (MIXED) ---- S --> (ALL_SET)     ; and report a MIXED region
1509*9880d681SAndroid Build Coastguard Worker   // (MIXED) ---- U --> (NONE)        ; and report a MIXED region
1510*9880d681SAndroid Build Coastguard Worker   // (MIXED) ---- M --> (MIXED)
1511*9880d681SAndroid Build Coastguard Worker 
1512*9880d681SAndroid Build Coastguard Worker   bitAttr_t RA = ATTR_NONE;
1513*9880d681SAndroid Build Coastguard Worker   unsigned StartBit = 0;
1514*9880d681SAndroid Build Coastguard Worker 
1515*9880d681SAndroid Build Coastguard Worker   for (BitIndex = 0; BitIndex < BitWidth; ++BitIndex) {
1516*9880d681SAndroid Build Coastguard Worker     bitAttr_t bitAttr = bitAttrs[BitIndex];
1517*9880d681SAndroid Build Coastguard Worker 
1518*9880d681SAndroid Build Coastguard Worker     assert(bitAttr != ATTR_NONE && "Bit without attributes");
1519*9880d681SAndroid Build Coastguard Worker 
1520*9880d681SAndroid Build Coastguard Worker     switch (RA) {
1521*9880d681SAndroid Build Coastguard Worker     case ATTR_NONE:
1522*9880d681SAndroid Build Coastguard Worker       switch (bitAttr) {
1523*9880d681SAndroid Build Coastguard Worker       case ATTR_FILTERED:
1524*9880d681SAndroid Build Coastguard Worker         break;
1525*9880d681SAndroid Build Coastguard Worker       case ATTR_ALL_SET:
1526*9880d681SAndroid Build Coastguard Worker         StartBit = BitIndex;
1527*9880d681SAndroid Build Coastguard Worker         RA = ATTR_ALL_SET;
1528*9880d681SAndroid Build Coastguard Worker         break;
1529*9880d681SAndroid Build Coastguard Worker       case ATTR_ALL_UNSET:
1530*9880d681SAndroid Build Coastguard Worker         break;
1531*9880d681SAndroid Build Coastguard Worker       case ATTR_MIXED:
1532*9880d681SAndroid Build Coastguard Worker         StartBit = BitIndex;
1533*9880d681SAndroid Build Coastguard Worker         RA = ATTR_MIXED;
1534*9880d681SAndroid Build Coastguard Worker         break;
1535*9880d681SAndroid Build Coastguard Worker       default:
1536*9880d681SAndroid Build Coastguard Worker         llvm_unreachable("Unexpected bitAttr!");
1537*9880d681SAndroid Build Coastguard Worker       }
1538*9880d681SAndroid Build Coastguard Worker       break;
1539*9880d681SAndroid Build Coastguard Worker     case ATTR_ALL_SET:
1540*9880d681SAndroid Build Coastguard Worker       switch (bitAttr) {
1541*9880d681SAndroid Build Coastguard Worker       case ATTR_FILTERED:
1542*9880d681SAndroid Build Coastguard Worker         reportRegion(RA, StartBit, BitIndex, AllowMixed);
1543*9880d681SAndroid Build Coastguard Worker         RA = ATTR_NONE;
1544*9880d681SAndroid Build Coastguard Worker         break;
1545*9880d681SAndroid Build Coastguard Worker       case ATTR_ALL_SET:
1546*9880d681SAndroid Build Coastguard Worker         break;
1547*9880d681SAndroid Build Coastguard Worker       case ATTR_ALL_UNSET:
1548*9880d681SAndroid Build Coastguard Worker         reportRegion(RA, StartBit, BitIndex, AllowMixed);
1549*9880d681SAndroid Build Coastguard Worker         RA = ATTR_NONE;
1550*9880d681SAndroid Build Coastguard Worker         break;
1551*9880d681SAndroid Build Coastguard Worker       case ATTR_MIXED:
1552*9880d681SAndroid Build Coastguard Worker         reportRegion(RA, StartBit, BitIndex, AllowMixed);
1553*9880d681SAndroid Build Coastguard Worker         StartBit = BitIndex;
1554*9880d681SAndroid Build Coastguard Worker         RA = ATTR_MIXED;
1555*9880d681SAndroid Build Coastguard Worker         break;
1556*9880d681SAndroid Build Coastguard Worker       default:
1557*9880d681SAndroid Build Coastguard Worker         llvm_unreachable("Unexpected bitAttr!");
1558*9880d681SAndroid Build Coastguard Worker       }
1559*9880d681SAndroid Build Coastguard Worker       break;
1560*9880d681SAndroid Build Coastguard Worker     case ATTR_MIXED:
1561*9880d681SAndroid Build Coastguard Worker       switch (bitAttr) {
1562*9880d681SAndroid Build Coastguard Worker       case ATTR_FILTERED:
1563*9880d681SAndroid Build Coastguard Worker         reportRegion(RA, StartBit, BitIndex, AllowMixed);
1564*9880d681SAndroid Build Coastguard Worker         StartBit = BitIndex;
1565*9880d681SAndroid Build Coastguard Worker         RA = ATTR_NONE;
1566*9880d681SAndroid Build Coastguard Worker         break;
1567*9880d681SAndroid Build Coastguard Worker       case ATTR_ALL_SET:
1568*9880d681SAndroid Build Coastguard Worker         reportRegion(RA, StartBit, BitIndex, AllowMixed);
1569*9880d681SAndroid Build Coastguard Worker         StartBit = BitIndex;
1570*9880d681SAndroid Build Coastguard Worker         RA = ATTR_ALL_SET;
1571*9880d681SAndroid Build Coastguard Worker         break;
1572*9880d681SAndroid Build Coastguard Worker       case ATTR_ALL_UNSET:
1573*9880d681SAndroid Build Coastguard Worker         reportRegion(RA, StartBit, BitIndex, AllowMixed);
1574*9880d681SAndroid Build Coastguard Worker         RA = ATTR_NONE;
1575*9880d681SAndroid Build Coastguard Worker         break;
1576*9880d681SAndroid Build Coastguard Worker       case ATTR_MIXED:
1577*9880d681SAndroid Build Coastguard Worker         break;
1578*9880d681SAndroid Build Coastguard Worker       default:
1579*9880d681SAndroid Build Coastguard Worker         llvm_unreachable("Unexpected bitAttr!");
1580*9880d681SAndroid Build Coastguard Worker       }
1581*9880d681SAndroid Build Coastguard Worker       break;
1582*9880d681SAndroid Build Coastguard Worker     case ATTR_ALL_UNSET:
1583*9880d681SAndroid Build Coastguard Worker       llvm_unreachable("regionAttr state machine has no ATTR_UNSET state");
1584*9880d681SAndroid Build Coastguard Worker     case ATTR_FILTERED:
1585*9880d681SAndroid Build Coastguard Worker       llvm_unreachable("regionAttr state machine has no ATTR_FILTERED state");
1586*9880d681SAndroid Build Coastguard Worker     }
1587*9880d681SAndroid Build Coastguard Worker   }
1588*9880d681SAndroid Build Coastguard Worker 
1589*9880d681SAndroid Build Coastguard Worker   // At the end, if we're still in ALL_SET or MIXED states, report a region
1590*9880d681SAndroid Build Coastguard Worker   switch (RA) {
1591*9880d681SAndroid Build Coastguard Worker   case ATTR_NONE:
1592*9880d681SAndroid Build Coastguard Worker     break;
1593*9880d681SAndroid Build Coastguard Worker   case ATTR_FILTERED:
1594*9880d681SAndroid Build Coastguard Worker     break;
1595*9880d681SAndroid Build Coastguard Worker   case ATTR_ALL_SET:
1596*9880d681SAndroid Build Coastguard Worker     reportRegion(RA, StartBit, BitIndex, AllowMixed);
1597*9880d681SAndroid Build Coastguard Worker     break;
1598*9880d681SAndroid Build Coastguard Worker   case ATTR_ALL_UNSET:
1599*9880d681SAndroid Build Coastguard Worker     break;
1600*9880d681SAndroid Build Coastguard Worker   case ATTR_MIXED:
1601*9880d681SAndroid Build Coastguard Worker     reportRegion(RA, StartBit, BitIndex, AllowMixed);
1602*9880d681SAndroid Build Coastguard Worker     break;
1603*9880d681SAndroid Build Coastguard Worker   }
1604*9880d681SAndroid Build Coastguard Worker 
1605*9880d681SAndroid Build Coastguard Worker   // We have finished with the filter processings.  Now it's time to choose
1606*9880d681SAndroid Build Coastguard Worker   // the best performing filter.
1607*9880d681SAndroid Build Coastguard Worker   BestIndex = 0;
1608*9880d681SAndroid Build Coastguard Worker   bool AllUseless = true;
1609*9880d681SAndroid Build Coastguard Worker   unsigned BestScore = 0;
1610*9880d681SAndroid Build Coastguard Worker 
1611*9880d681SAndroid Build Coastguard Worker   for (unsigned i = 0, e = Filters.size(); i != e; ++i) {
1612*9880d681SAndroid Build Coastguard Worker     unsigned Usefulness = Filters[i].usefulness();
1613*9880d681SAndroid Build Coastguard Worker 
1614*9880d681SAndroid Build Coastguard Worker     if (Usefulness)
1615*9880d681SAndroid Build Coastguard Worker       AllUseless = false;
1616*9880d681SAndroid Build Coastguard Worker 
1617*9880d681SAndroid Build Coastguard Worker     if (Usefulness > BestScore) {
1618*9880d681SAndroid Build Coastguard Worker       BestIndex = i;
1619*9880d681SAndroid Build Coastguard Worker       BestScore = Usefulness;
1620*9880d681SAndroid Build Coastguard Worker     }
1621*9880d681SAndroid Build Coastguard Worker   }
1622*9880d681SAndroid Build Coastguard Worker 
1623*9880d681SAndroid Build Coastguard Worker   if (!AllUseless)
1624*9880d681SAndroid Build Coastguard Worker     bestFilter().recurse();
1625*9880d681SAndroid Build Coastguard Worker 
1626*9880d681SAndroid Build Coastguard Worker   return !AllUseless;
1627*9880d681SAndroid Build Coastguard Worker } // end of FilterChooser::filterProcessor(bool)
1628*9880d681SAndroid Build Coastguard Worker 
1629*9880d681SAndroid Build Coastguard Worker // Decides on the best configuration of filter(s) to use in order to decode
1630*9880d681SAndroid Build Coastguard Worker // the instructions.  A conflict of instructions may occur, in which case we
1631*9880d681SAndroid Build Coastguard Worker // dump the conflict set to the standard error.
doFilter()1632*9880d681SAndroid Build Coastguard Worker void FilterChooser::doFilter() {
1633*9880d681SAndroid Build Coastguard Worker   unsigned Num = Opcodes.size();
1634*9880d681SAndroid Build Coastguard Worker   assert(Num && "FilterChooser created with no instructions");
1635*9880d681SAndroid Build Coastguard Worker 
1636*9880d681SAndroid Build Coastguard Worker   // Try regions of consecutive known bit values first.
1637*9880d681SAndroid Build Coastguard Worker   if (filterProcessor(false))
1638*9880d681SAndroid Build Coastguard Worker     return;
1639*9880d681SAndroid Build Coastguard Worker 
1640*9880d681SAndroid Build Coastguard Worker   // Then regions of mixed bits (both known and unitialized bit values allowed).
1641*9880d681SAndroid Build Coastguard Worker   if (filterProcessor(true))
1642*9880d681SAndroid Build Coastguard Worker     return;
1643*9880d681SAndroid Build Coastguard Worker 
1644*9880d681SAndroid Build Coastguard Worker   // Heuristics to cope with conflict set {t2CMPrs, t2SUBSrr, t2SUBSrs} where
1645*9880d681SAndroid Build Coastguard Worker   // no single instruction for the maximum ATTR_MIXED region Inst{14-4} has a
1646*9880d681SAndroid Build Coastguard Worker   // well-known encoding pattern.  In such case, we backtrack and scan for the
1647*9880d681SAndroid Build Coastguard Worker   // the very first consecutive ATTR_ALL_SET region and assign a filter to it.
1648*9880d681SAndroid Build Coastguard Worker   if (Num == 3 && filterProcessor(true, false))
1649*9880d681SAndroid Build Coastguard Worker     return;
1650*9880d681SAndroid Build Coastguard Worker 
1651*9880d681SAndroid Build Coastguard Worker   // If we come to here, the instruction decoding has failed.
1652*9880d681SAndroid Build Coastguard Worker   // Set the BestIndex to -1 to indicate so.
1653*9880d681SAndroid Build Coastguard Worker   BestIndex = -1;
1654*9880d681SAndroid Build Coastguard Worker }
1655*9880d681SAndroid Build Coastguard Worker 
1656*9880d681SAndroid Build Coastguard Worker // emitTableEntries - Emit state machine entries to decode our share of
1657*9880d681SAndroid Build Coastguard Worker // instructions.
emitTableEntries(DecoderTableInfo & TableInfo) const1658*9880d681SAndroid Build Coastguard Worker void FilterChooser::emitTableEntries(DecoderTableInfo &TableInfo) const {
1659*9880d681SAndroid Build Coastguard Worker   if (Opcodes.size() == 1) {
1660*9880d681SAndroid Build Coastguard Worker     // There is only one instruction in the set, which is great!
1661*9880d681SAndroid Build Coastguard Worker     // Call emitSingletonDecoder() to see whether there are any remaining
1662*9880d681SAndroid Build Coastguard Worker     // encodings bits.
1663*9880d681SAndroid Build Coastguard Worker     emitSingletonTableEntry(TableInfo, Opcodes[0]);
1664*9880d681SAndroid Build Coastguard Worker     return;
1665*9880d681SAndroid Build Coastguard Worker   }
1666*9880d681SAndroid Build Coastguard Worker 
1667*9880d681SAndroid Build Coastguard Worker   // Choose the best filter to do the decodings!
1668*9880d681SAndroid Build Coastguard Worker   if (BestIndex != -1) {
1669*9880d681SAndroid Build Coastguard Worker     const Filter &Best = Filters[BestIndex];
1670*9880d681SAndroid Build Coastguard Worker     if (Best.getNumFiltered() == 1)
1671*9880d681SAndroid Build Coastguard Worker       emitSingletonTableEntry(TableInfo, Best);
1672*9880d681SAndroid Build Coastguard Worker     else
1673*9880d681SAndroid Build Coastguard Worker       Best.emitTableEntry(TableInfo);
1674*9880d681SAndroid Build Coastguard Worker     return;
1675*9880d681SAndroid Build Coastguard Worker   }
1676*9880d681SAndroid Build Coastguard Worker 
1677*9880d681SAndroid Build Coastguard Worker   // We don't know how to decode these instructions!  Dump the
1678*9880d681SAndroid Build Coastguard Worker   // conflict set and bail.
1679*9880d681SAndroid Build Coastguard Worker 
1680*9880d681SAndroid Build Coastguard Worker   // Print out useful conflict information for postmortem analysis.
1681*9880d681SAndroid Build Coastguard Worker   errs() << "Decoding Conflict:\n";
1682*9880d681SAndroid Build Coastguard Worker 
1683*9880d681SAndroid Build Coastguard Worker   dumpStack(errs(), "\t\t");
1684*9880d681SAndroid Build Coastguard Worker 
1685*9880d681SAndroid Build Coastguard Worker   for (unsigned i = 0; i < Opcodes.size(); ++i) {
1686*9880d681SAndroid Build Coastguard Worker     const std::string &Name = nameWithID(Opcodes[i]);
1687*9880d681SAndroid Build Coastguard Worker 
1688*9880d681SAndroid Build Coastguard Worker     errs() << '\t' << Name << " ";
1689*9880d681SAndroid Build Coastguard Worker     dumpBits(errs(),
1690*9880d681SAndroid Build Coastguard Worker              getBitsField(*AllInstructions[Opcodes[i]]->TheDef, "Inst"));
1691*9880d681SAndroid Build Coastguard Worker     errs() << '\n';
1692*9880d681SAndroid Build Coastguard Worker   }
1693*9880d681SAndroid Build Coastguard Worker }
1694*9880d681SAndroid Build Coastguard Worker 
populateInstruction(CodeGenTarget & Target,const CodeGenInstruction & CGI,unsigned Opc,std::map<unsigned,std::vector<OperandInfo>> & Operands)1695*9880d681SAndroid Build Coastguard Worker static bool populateInstruction(CodeGenTarget &Target,
1696*9880d681SAndroid Build Coastguard Worker                        const CodeGenInstruction &CGI, unsigned Opc,
1697*9880d681SAndroid Build Coastguard Worker                        std::map<unsigned, std::vector<OperandInfo> > &Operands){
1698*9880d681SAndroid Build Coastguard Worker   const Record &Def = *CGI.TheDef;
1699*9880d681SAndroid Build Coastguard Worker   // If all the bit positions are not specified; do not decode this instruction.
1700*9880d681SAndroid Build Coastguard Worker   // We are bound to fail!  For proper disassembly, the well-known encoding bits
1701*9880d681SAndroid Build Coastguard Worker   // of the instruction must be fully specified.
1702*9880d681SAndroid Build Coastguard Worker 
1703*9880d681SAndroid Build Coastguard Worker   BitsInit &Bits = getBitsField(Def, "Inst");
1704*9880d681SAndroid Build Coastguard Worker   if (Bits.allInComplete()) return false;
1705*9880d681SAndroid Build Coastguard Worker 
1706*9880d681SAndroid Build Coastguard Worker   std::vector<OperandInfo> InsnOperands;
1707*9880d681SAndroid Build Coastguard Worker 
1708*9880d681SAndroid Build Coastguard Worker   // If the instruction has specified a custom decoding hook, use that instead
1709*9880d681SAndroid Build Coastguard Worker   // of trying to auto-generate the decoder.
1710*9880d681SAndroid Build Coastguard Worker   std::string InstDecoder = Def.getValueAsString("DecoderMethod");
1711*9880d681SAndroid Build Coastguard Worker   if (InstDecoder != "") {
1712*9880d681SAndroid Build Coastguard Worker     bool HasCompleteInstDecoder = Def.getValueAsBit("hasCompleteDecoder");
1713*9880d681SAndroid Build Coastguard Worker     InsnOperands.push_back(OperandInfo(InstDecoder, HasCompleteInstDecoder));
1714*9880d681SAndroid Build Coastguard Worker     Operands[Opc] = InsnOperands;
1715*9880d681SAndroid Build Coastguard Worker     return true;
1716*9880d681SAndroid Build Coastguard Worker   }
1717*9880d681SAndroid Build Coastguard Worker 
1718*9880d681SAndroid Build Coastguard Worker   // Generate a description of the operand of the instruction that we know
1719*9880d681SAndroid Build Coastguard Worker   // how to decode automatically.
1720*9880d681SAndroid Build Coastguard Worker   // FIXME: We'll need to have a way to manually override this as needed.
1721*9880d681SAndroid Build Coastguard Worker 
1722*9880d681SAndroid Build Coastguard Worker   // Gather the outputs/inputs of the instruction, so we can find their
1723*9880d681SAndroid Build Coastguard Worker   // positions in the encoding.  This assumes for now that they appear in the
1724*9880d681SAndroid Build Coastguard Worker   // MCInst in the order that they're listed.
1725*9880d681SAndroid Build Coastguard Worker   std::vector<std::pair<Init*, std::string> > InOutOperands;
1726*9880d681SAndroid Build Coastguard Worker   DagInit *Out  = Def.getValueAsDag("OutOperandList");
1727*9880d681SAndroid Build Coastguard Worker   DagInit *In  = Def.getValueAsDag("InOperandList");
1728*9880d681SAndroid Build Coastguard Worker   for (unsigned i = 0; i < Out->getNumArgs(); ++i)
1729*9880d681SAndroid Build Coastguard Worker     InOutOperands.push_back(std::make_pair(Out->getArg(i), Out->getArgName(i)));
1730*9880d681SAndroid Build Coastguard Worker   for (unsigned i = 0; i < In->getNumArgs(); ++i)
1731*9880d681SAndroid Build Coastguard Worker     InOutOperands.push_back(std::make_pair(In->getArg(i), In->getArgName(i)));
1732*9880d681SAndroid Build Coastguard Worker 
1733*9880d681SAndroid Build Coastguard Worker   // Search for tied operands, so that we can correctly instantiate
1734*9880d681SAndroid Build Coastguard Worker   // operands that are not explicitly represented in the encoding.
1735*9880d681SAndroid Build Coastguard Worker   std::map<std::string, std::string> TiedNames;
1736*9880d681SAndroid Build Coastguard Worker   for (unsigned i = 0; i < CGI.Operands.size(); ++i) {
1737*9880d681SAndroid Build Coastguard Worker     int tiedTo = CGI.Operands[i].getTiedRegister();
1738*9880d681SAndroid Build Coastguard Worker     if (tiedTo != -1) {
1739*9880d681SAndroid Build Coastguard Worker       std::pair<unsigned, unsigned> SO =
1740*9880d681SAndroid Build Coastguard Worker         CGI.Operands.getSubOperandNumber(tiedTo);
1741*9880d681SAndroid Build Coastguard Worker       TiedNames[InOutOperands[i].second] = InOutOperands[SO.first].second;
1742*9880d681SAndroid Build Coastguard Worker       TiedNames[InOutOperands[SO.first].second] = InOutOperands[i].second;
1743*9880d681SAndroid Build Coastguard Worker     }
1744*9880d681SAndroid Build Coastguard Worker   }
1745*9880d681SAndroid Build Coastguard Worker 
1746*9880d681SAndroid Build Coastguard Worker   std::map<std::string, std::vector<OperandInfo> > NumberedInsnOperands;
1747*9880d681SAndroid Build Coastguard Worker   std::set<std::string> NumberedInsnOperandsNoTie;
1748*9880d681SAndroid Build Coastguard Worker   if (Target.getInstructionSet()->
1749*9880d681SAndroid Build Coastguard Worker         getValueAsBit("decodePositionallyEncodedOperands")) {
1750*9880d681SAndroid Build Coastguard Worker     const std::vector<RecordVal> &Vals = Def.getValues();
1751*9880d681SAndroid Build Coastguard Worker     unsigned NumberedOp = 0;
1752*9880d681SAndroid Build Coastguard Worker 
1753*9880d681SAndroid Build Coastguard Worker     std::set<unsigned> NamedOpIndices;
1754*9880d681SAndroid Build Coastguard Worker     if (Target.getInstructionSet()->
1755*9880d681SAndroid Build Coastguard Worker          getValueAsBit("noNamedPositionallyEncodedOperands"))
1756*9880d681SAndroid Build Coastguard Worker       // Collect the set of operand indices that might correspond to named
1757*9880d681SAndroid Build Coastguard Worker       // operand, and skip these when assigning operands based on position.
1758*9880d681SAndroid Build Coastguard Worker       for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1759*9880d681SAndroid Build Coastguard Worker         unsigned OpIdx;
1760*9880d681SAndroid Build Coastguard Worker         if (!CGI.Operands.hasOperandNamed(Vals[i].getName(), OpIdx))
1761*9880d681SAndroid Build Coastguard Worker           continue;
1762*9880d681SAndroid Build Coastguard Worker 
1763*9880d681SAndroid Build Coastguard Worker         NamedOpIndices.insert(OpIdx);
1764*9880d681SAndroid Build Coastguard Worker       }
1765*9880d681SAndroid Build Coastguard Worker 
1766*9880d681SAndroid Build Coastguard Worker     for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1767*9880d681SAndroid Build Coastguard Worker       // Ignore fixed fields in the record, we're looking for values like:
1768*9880d681SAndroid Build Coastguard Worker       //    bits<5> RST = { ?, ?, ?, ?, ? };
1769*9880d681SAndroid Build Coastguard Worker       if (Vals[i].getPrefix() || Vals[i].getValue()->isComplete())
1770*9880d681SAndroid Build Coastguard Worker         continue;
1771*9880d681SAndroid Build Coastguard Worker 
1772*9880d681SAndroid Build Coastguard Worker       // Determine if Vals[i] actually contributes to the Inst encoding.
1773*9880d681SAndroid Build Coastguard Worker       unsigned bi = 0;
1774*9880d681SAndroid Build Coastguard Worker       for (; bi < Bits.getNumBits(); ++bi) {
1775*9880d681SAndroid Build Coastguard Worker         VarInit *Var = nullptr;
1776*9880d681SAndroid Build Coastguard Worker         VarBitInit *BI = dyn_cast<VarBitInit>(Bits.getBit(bi));
1777*9880d681SAndroid Build Coastguard Worker         if (BI)
1778*9880d681SAndroid Build Coastguard Worker           Var = dyn_cast<VarInit>(BI->getBitVar());
1779*9880d681SAndroid Build Coastguard Worker         else
1780*9880d681SAndroid Build Coastguard Worker           Var = dyn_cast<VarInit>(Bits.getBit(bi));
1781*9880d681SAndroid Build Coastguard Worker 
1782*9880d681SAndroid Build Coastguard Worker         if (Var && Var->getName() == Vals[i].getName())
1783*9880d681SAndroid Build Coastguard Worker           break;
1784*9880d681SAndroid Build Coastguard Worker       }
1785*9880d681SAndroid Build Coastguard Worker 
1786*9880d681SAndroid Build Coastguard Worker       if (bi == Bits.getNumBits())
1787*9880d681SAndroid Build Coastguard Worker         continue;
1788*9880d681SAndroid Build Coastguard Worker 
1789*9880d681SAndroid Build Coastguard Worker       // Skip variables that correspond to explicitly-named operands.
1790*9880d681SAndroid Build Coastguard Worker       unsigned OpIdx;
1791*9880d681SAndroid Build Coastguard Worker       if (CGI.Operands.hasOperandNamed(Vals[i].getName(), OpIdx))
1792*9880d681SAndroid Build Coastguard Worker         continue;
1793*9880d681SAndroid Build Coastguard Worker 
1794*9880d681SAndroid Build Coastguard Worker       // Get the bit range for this operand:
1795*9880d681SAndroid Build Coastguard Worker       unsigned bitStart = bi++, bitWidth = 1;
1796*9880d681SAndroid Build Coastguard Worker       for (; bi < Bits.getNumBits(); ++bi) {
1797*9880d681SAndroid Build Coastguard Worker         VarInit *Var = nullptr;
1798*9880d681SAndroid Build Coastguard Worker         VarBitInit *BI = dyn_cast<VarBitInit>(Bits.getBit(bi));
1799*9880d681SAndroid Build Coastguard Worker         if (BI)
1800*9880d681SAndroid Build Coastguard Worker           Var = dyn_cast<VarInit>(BI->getBitVar());
1801*9880d681SAndroid Build Coastguard Worker         else
1802*9880d681SAndroid Build Coastguard Worker           Var = dyn_cast<VarInit>(Bits.getBit(bi));
1803*9880d681SAndroid Build Coastguard Worker 
1804*9880d681SAndroid Build Coastguard Worker         if (!Var)
1805*9880d681SAndroid Build Coastguard Worker           break;
1806*9880d681SAndroid Build Coastguard Worker 
1807*9880d681SAndroid Build Coastguard Worker         if (Var->getName() != Vals[i].getName())
1808*9880d681SAndroid Build Coastguard Worker           break;
1809*9880d681SAndroid Build Coastguard Worker 
1810*9880d681SAndroid Build Coastguard Worker         ++bitWidth;
1811*9880d681SAndroid Build Coastguard Worker       }
1812*9880d681SAndroid Build Coastguard Worker 
1813*9880d681SAndroid Build Coastguard Worker       unsigned NumberOps = CGI.Operands.size();
1814*9880d681SAndroid Build Coastguard Worker       while (NumberedOp < NumberOps &&
1815*9880d681SAndroid Build Coastguard Worker              (CGI.Operands.isFlatOperandNotEmitted(NumberedOp) ||
1816*9880d681SAndroid Build Coastguard Worker               (!NamedOpIndices.empty() && NamedOpIndices.count(
1817*9880d681SAndroid Build Coastguard Worker                 CGI.Operands.getSubOperandNumber(NumberedOp).first))))
1818*9880d681SAndroid Build Coastguard Worker         ++NumberedOp;
1819*9880d681SAndroid Build Coastguard Worker 
1820*9880d681SAndroid Build Coastguard Worker       OpIdx = NumberedOp++;
1821*9880d681SAndroid Build Coastguard Worker 
1822*9880d681SAndroid Build Coastguard Worker       // OpIdx now holds the ordered operand number of Vals[i].
1823*9880d681SAndroid Build Coastguard Worker       std::pair<unsigned, unsigned> SO =
1824*9880d681SAndroid Build Coastguard Worker         CGI.Operands.getSubOperandNumber(OpIdx);
1825*9880d681SAndroid Build Coastguard Worker       const std::string &Name = CGI.Operands[SO.first].Name;
1826*9880d681SAndroid Build Coastguard Worker 
1827*9880d681SAndroid Build Coastguard Worker       DEBUG(dbgs() << "Numbered operand mapping for " << Def.getName() << ": " <<
1828*9880d681SAndroid Build Coastguard Worker                       Name << "(" << SO.first << ", " << SO.second << ") => " <<
1829*9880d681SAndroid Build Coastguard Worker                       Vals[i].getName() << "\n");
1830*9880d681SAndroid Build Coastguard Worker 
1831*9880d681SAndroid Build Coastguard Worker       std::string Decoder = "";
1832*9880d681SAndroid Build Coastguard Worker       Record *TypeRecord = CGI.Operands[SO.first].Rec;
1833*9880d681SAndroid Build Coastguard Worker 
1834*9880d681SAndroid Build Coastguard Worker       RecordVal *DecoderString = TypeRecord->getValue("DecoderMethod");
1835*9880d681SAndroid Build Coastguard Worker       StringInit *String = DecoderString ?
1836*9880d681SAndroid Build Coastguard Worker         dyn_cast<StringInit>(DecoderString->getValue()) : nullptr;
1837*9880d681SAndroid Build Coastguard Worker       if (String && String->getValue() != "")
1838*9880d681SAndroid Build Coastguard Worker         Decoder = String->getValue();
1839*9880d681SAndroid Build Coastguard Worker 
1840*9880d681SAndroid Build Coastguard Worker       if (Decoder == "" &&
1841*9880d681SAndroid Build Coastguard Worker           CGI.Operands[SO.first].MIOperandInfo &&
1842*9880d681SAndroid Build Coastguard Worker           CGI.Operands[SO.first].MIOperandInfo->getNumArgs()) {
1843*9880d681SAndroid Build Coastguard Worker         Init *Arg = CGI.Operands[SO.first].MIOperandInfo->
1844*9880d681SAndroid Build Coastguard Worker                       getArg(SO.second);
1845*9880d681SAndroid Build Coastguard Worker         if (TypedInit *TI = cast<TypedInit>(Arg)) {
1846*9880d681SAndroid Build Coastguard Worker           RecordRecTy *Type = cast<RecordRecTy>(TI->getType());
1847*9880d681SAndroid Build Coastguard Worker           TypeRecord = Type->getRecord();
1848*9880d681SAndroid Build Coastguard Worker         }
1849*9880d681SAndroid Build Coastguard Worker       }
1850*9880d681SAndroid Build Coastguard Worker 
1851*9880d681SAndroid Build Coastguard Worker       bool isReg = false;
1852*9880d681SAndroid Build Coastguard Worker       if (TypeRecord->isSubClassOf("RegisterOperand"))
1853*9880d681SAndroid Build Coastguard Worker         TypeRecord = TypeRecord->getValueAsDef("RegClass");
1854*9880d681SAndroid Build Coastguard Worker       if (TypeRecord->isSubClassOf("RegisterClass")) {
1855*9880d681SAndroid Build Coastguard Worker         Decoder = "Decode" + TypeRecord->getName() + "RegisterClass";
1856*9880d681SAndroid Build Coastguard Worker         isReg = true;
1857*9880d681SAndroid Build Coastguard Worker       } else if (TypeRecord->isSubClassOf("PointerLikeRegClass")) {
1858*9880d681SAndroid Build Coastguard Worker         Decoder = "DecodePointerLikeRegClass" +
1859*9880d681SAndroid Build Coastguard Worker                   utostr(TypeRecord->getValueAsInt("RegClassKind"));
1860*9880d681SAndroid Build Coastguard Worker         isReg = true;
1861*9880d681SAndroid Build Coastguard Worker       }
1862*9880d681SAndroid Build Coastguard Worker 
1863*9880d681SAndroid Build Coastguard Worker       DecoderString = TypeRecord->getValue("DecoderMethod");
1864*9880d681SAndroid Build Coastguard Worker       String = DecoderString ?
1865*9880d681SAndroid Build Coastguard Worker         dyn_cast<StringInit>(DecoderString->getValue()) : nullptr;
1866*9880d681SAndroid Build Coastguard Worker       if (!isReg && String && String->getValue() != "")
1867*9880d681SAndroid Build Coastguard Worker         Decoder = String->getValue();
1868*9880d681SAndroid Build Coastguard Worker 
1869*9880d681SAndroid Build Coastguard Worker       RecordVal *HasCompleteDecoderVal =
1870*9880d681SAndroid Build Coastguard Worker         TypeRecord->getValue("hasCompleteDecoder");
1871*9880d681SAndroid Build Coastguard Worker       BitInit *HasCompleteDecoderBit = HasCompleteDecoderVal ?
1872*9880d681SAndroid Build Coastguard Worker         dyn_cast<BitInit>(HasCompleteDecoderVal->getValue()) : nullptr;
1873*9880d681SAndroid Build Coastguard Worker       bool HasCompleteDecoder = HasCompleteDecoderBit ?
1874*9880d681SAndroid Build Coastguard Worker         HasCompleteDecoderBit->getValue() : true;
1875*9880d681SAndroid Build Coastguard Worker 
1876*9880d681SAndroid Build Coastguard Worker       OperandInfo OpInfo(Decoder, HasCompleteDecoder);
1877*9880d681SAndroid Build Coastguard Worker       OpInfo.addField(bitStart, bitWidth, 0);
1878*9880d681SAndroid Build Coastguard Worker 
1879*9880d681SAndroid Build Coastguard Worker       NumberedInsnOperands[Name].push_back(OpInfo);
1880*9880d681SAndroid Build Coastguard Worker 
1881*9880d681SAndroid Build Coastguard Worker       // FIXME: For complex operands with custom decoders we can't handle tied
1882*9880d681SAndroid Build Coastguard Worker       // sub-operands automatically. Skip those here and assume that this is
1883*9880d681SAndroid Build Coastguard Worker       // fixed up elsewhere.
1884*9880d681SAndroid Build Coastguard Worker       if (CGI.Operands[SO.first].MIOperandInfo &&
1885*9880d681SAndroid Build Coastguard Worker           CGI.Operands[SO.first].MIOperandInfo->getNumArgs() > 1 &&
1886*9880d681SAndroid Build Coastguard Worker           String && String->getValue() != "")
1887*9880d681SAndroid Build Coastguard Worker         NumberedInsnOperandsNoTie.insert(Name);
1888*9880d681SAndroid Build Coastguard Worker     }
1889*9880d681SAndroid Build Coastguard Worker   }
1890*9880d681SAndroid Build Coastguard Worker 
1891*9880d681SAndroid Build Coastguard Worker   // For each operand, see if we can figure out where it is encoded.
1892*9880d681SAndroid Build Coastguard Worker   for (const auto &Op : InOutOperands) {
1893*9880d681SAndroid Build Coastguard Worker     if (!NumberedInsnOperands[Op.second].empty()) {
1894*9880d681SAndroid Build Coastguard Worker       InsnOperands.insert(InsnOperands.end(),
1895*9880d681SAndroid Build Coastguard Worker                           NumberedInsnOperands[Op.second].begin(),
1896*9880d681SAndroid Build Coastguard Worker                           NumberedInsnOperands[Op.second].end());
1897*9880d681SAndroid Build Coastguard Worker       continue;
1898*9880d681SAndroid Build Coastguard Worker     }
1899*9880d681SAndroid Build Coastguard Worker     if (!NumberedInsnOperands[TiedNames[Op.second]].empty()) {
1900*9880d681SAndroid Build Coastguard Worker       if (!NumberedInsnOperandsNoTie.count(TiedNames[Op.second])) {
1901*9880d681SAndroid Build Coastguard Worker         // Figure out to which (sub)operand we're tied.
1902*9880d681SAndroid Build Coastguard Worker         unsigned i = CGI.Operands.getOperandNamed(TiedNames[Op.second]);
1903*9880d681SAndroid Build Coastguard Worker         int tiedTo = CGI.Operands[i].getTiedRegister();
1904*9880d681SAndroid Build Coastguard Worker         if (tiedTo == -1) {
1905*9880d681SAndroid Build Coastguard Worker           i = CGI.Operands.getOperandNamed(Op.second);
1906*9880d681SAndroid Build Coastguard Worker           tiedTo = CGI.Operands[i].getTiedRegister();
1907*9880d681SAndroid Build Coastguard Worker         }
1908*9880d681SAndroid Build Coastguard Worker 
1909*9880d681SAndroid Build Coastguard Worker         if (tiedTo != -1) {
1910*9880d681SAndroid Build Coastguard Worker           std::pair<unsigned, unsigned> SO =
1911*9880d681SAndroid Build Coastguard Worker             CGI.Operands.getSubOperandNumber(tiedTo);
1912*9880d681SAndroid Build Coastguard Worker 
1913*9880d681SAndroid Build Coastguard Worker           InsnOperands.push_back(NumberedInsnOperands[TiedNames[Op.second]]
1914*9880d681SAndroid Build Coastguard Worker                                    [SO.second]);
1915*9880d681SAndroid Build Coastguard Worker         }
1916*9880d681SAndroid Build Coastguard Worker       }
1917*9880d681SAndroid Build Coastguard Worker       continue;
1918*9880d681SAndroid Build Coastguard Worker     }
1919*9880d681SAndroid Build Coastguard Worker 
1920*9880d681SAndroid Build Coastguard Worker     std::string Decoder = "";
1921*9880d681SAndroid Build Coastguard Worker 
1922*9880d681SAndroid Build Coastguard Worker     // At this point, we can locate the field, but we need to know how to
1923*9880d681SAndroid Build Coastguard Worker     // interpret it.  As a first step, require the target to provide callbacks
1924*9880d681SAndroid Build Coastguard Worker     // for decoding register classes.
1925*9880d681SAndroid Build Coastguard Worker     // FIXME: This need to be extended to handle instructions with custom
1926*9880d681SAndroid Build Coastguard Worker     // decoder methods, and operands with (simple) MIOperandInfo's.
1927*9880d681SAndroid Build Coastguard Worker     TypedInit *TI = cast<TypedInit>(Op.first);
1928*9880d681SAndroid Build Coastguard Worker     RecordRecTy *Type = cast<RecordRecTy>(TI->getType());
1929*9880d681SAndroid Build Coastguard Worker     Record *TypeRecord = Type->getRecord();
1930*9880d681SAndroid Build Coastguard Worker     bool isReg = false;
1931*9880d681SAndroid Build Coastguard Worker     if (TypeRecord->isSubClassOf("RegisterOperand"))
1932*9880d681SAndroid Build Coastguard Worker       TypeRecord = TypeRecord->getValueAsDef("RegClass");
1933*9880d681SAndroid Build Coastguard Worker     if (TypeRecord->isSubClassOf("RegisterClass")) {
1934*9880d681SAndroid Build Coastguard Worker       Decoder = "Decode" + TypeRecord->getName() + "RegisterClass";
1935*9880d681SAndroid Build Coastguard Worker       isReg = true;
1936*9880d681SAndroid Build Coastguard Worker     } else if (TypeRecord->isSubClassOf("PointerLikeRegClass")) {
1937*9880d681SAndroid Build Coastguard Worker       Decoder = "DecodePointerLikeRegClass" +
1938*9880d681SAndroid Build Coastguard Worker                 utostr(TypeRecord->getValueAsInt("RegClassKind"));
1939*9880d681SAndroid Build Coastguard Worker       isReg = true;
1940*9880d681SAndroid Build Coastguard Worker     }
1941*9880d681SAndroid Build Coastguard Worker 
1942*9880d681SAndroid Build Coastguard Worker     RecordVal *DecoderString = TypeRecord->getValue("DecoderMethod");
1943*9880d681SAndroid Build Coastguard Worker     StringInit *String = DecoderString ?
1944*9880d681SAndroid Build Coastguard Worker       dyn_cast<StringInit>(DecoderString->getValue()) : nullptr;
1945*9880d681SAndroid Build Coastguard Worker     if (!isReg && String && String->getValue() != "")
1946*9880d681SAndroid Build Coastguard Worker       Decoder = String->getValue();
1947*9880d681SAndroid Build Coastguard Worker 
1948*9880d681SAndroid Build Coastguard Worker     RecordVal *HasCompleteDecoderVal =
1949*9880d681SAndroid Build Coastguard Worker       TypeRecord->getValue("hasCompleteDecoder");
1950*9880d681SAndroid Build Coastguard Worker     BitInit *HasCompleteDecoderBit = HasCompleteDecoderVal ?
1951*9880d681SAndroid Build Coastguard Worker       dyn_cast<BitInit>(HasCompleteDecoderVal->getValue()) : nullptr;
1952*9880d681SAndroid Build Coastguard Worker     bool HasCompleteDecoder = HasCompleteDecoderBit ?
1953*9880d681SAndroid Build Coastguard Worker       HasCompleteDecoderBit->getValue() : true;
1954*9880d681SAndroid Build Coastguard Worker 
1955*9880d681SAndroid Build Coastguard Worker     OperandInfo OpInfo(Decoder, HasCompleteDecoder);
1956*9880d681SAndroid Build Coastguard Worker     unsigned Base = ~0U;
1957*9880d681SAndroid Build Coastguard Worker     unsigned Width = 0;
1958*9880d681SAndroid Build Coastguard Worker     unsigned Offset = 0;
1959*9880d681SAndroid Build Coastguard Worker 
1960*9880d681SAndroid Build Coastguard Worker     for (unsigned bi = 0; bi < Bits.getNumBits(); ++bi) {
1961*9880d681SAndroid Build Coastguard Worker       VarInit *Var = nullptr;
1962*9880d681SAndroid Build Coastguard Worker       VarBitInit *BI = dyn_cast<VarBitInit>(Bits.getBit(bi));
1963*9880d681SAndroid Build Coastguard Worker       if (BI)
1964*9880d681SAndroid Build Coastguard Worker         Var = dyn_cast<VarInit>(BI->getBitVar());
1965*9880d681SAndroid Build Coastguard Worker       else
1966*9880d681SAndroid Build Coastguard Worker         Var = dyn_cast<VarInit>(Bits.getBit(bi));
1967*9880d681SAndroid Build Coastguard Worker 
1968*9880d681SAndroid Build Coastguard Worker       if (!Var) {
1969*9880d681SAndroid Build Coastguard Worker         if (Base != ~0U) {
1970*9880d681SAndroid Build Coastguard Worker           OpInfo.addField(Base, Width, Offset);
1971*9880d681SAndroid Build Coastguard Worker           Base = ~0U;
1972*9880d681SAndroid Build Coastguard Worker           Width = 0;
1973*9880d681SAndroid Build Coastguard Worker           Offset = 0;
1974*9880d681SAndroid Build Coastguard Worker         }
1975*9880d681SAndroid Build Coastguard Worker         continue;
1976*9880d681SAndroid Build Coastguard Worker       }
1977*9880d681SAndroid Build Coastguard Worker 
1978*9880d681SAndroid Build Coastguard Worker       if (Var->getName() != Op.second &&
1979*9880d681SAndroid Build Coastguard Worker           Var->getName() != TiedNames[Op.second]) {
1980*9880d681SAndroid Build Coastguard Worker         if (Base != ~0U) {
1981*9880d681SAndroid Build Coastguard Worker           OpInfo.addField(Base, Width, Offset);
1982*9880d681SAndroid Build Coastguard Worker           Base = ~0U;
1983*9880d681SAndroid Build Coastguard Worker           Width = 0;
1984*9880d681SAndroid Build Coastguard Worker           Offset = 0;
1985*9880d681SAndroid Build Coastguard Worker         }
1986*9880d681SAndroid Build Coastguard Worker         continue;
1987*9880d681SAndroid Build Coastguard Worker       }
1988*9880d681SAndroid Build Coastguard Worker 
1989*9880d681SAndroid Build Coastguard Worker       if (Base == ~0U) {
1990*9880d681SAndroid Build Coastguard Worker         Base = bi;
1991*9880d681SAndroid Build Coastguard Worker         Width = 1;
1992*9880d681SAndroid Build Coastguard Worker         Offset = BI ? BI->getBitNum() : 0;
1993*9880d681SAndroid Build Coastguard Worker       } else if (BI && BI->getBitNum() != Offset + Width) {
1994*9880d681SAndroid Build Coastguard Worker         OpInfo.addField(Base, Width, Offset);
1995*9880d681SAndroid Build Coastguard Worker         Base = bi;
1996*9880d681SAndroid Build Coastguard Worker         Width = 1;
1997*9880d681SAndroid Build Coastguard Worker         Offset = BI->getBitNum();
1998*9880d681SAndroid Build Coastguard Worker       } else {
1999*9880d681SAndroid Build Coastguard Worker         ++Width;
2000*9880d681SAndroid Build Coastguard Worker       }
2001*9880d681SAndroid Build Coastguard Worker     }
2002*9880d681SAndroid Build Coastguard Worker 
2003*9880d681SAndroid Build Coastguard Worker     if (Base != ~0U)
2004*9880d681SAndroid Build Coastguard Worker       OpInfo.addField(Base, Width, Offset);
2005*9880d681SAndroid Build Coastguard Worker 
2006*9880d681SAndroid Build Coastguard Worker     if (OpInfo.numFields() > 0)
2007*9880d681SAndroid Build Coastguard Worker       InsnOperands.push_back(OpInfo);
2008*9880d681SAndroid Build Coastguard Worker   }
2009*9880d681SAndroid Build Coastguard Worker 
2010*9880d681SAndroid Build Coastguard Worker   Operands[Opc] = InsnOperands;
2011*9880d681SAndroid Build Coastguard Worker 
2012*9880d681SAndroid Build Coastguard Worker 
2013*9880d681SAndroid Build Coastguard Worker #if 0
2014*9880d681SAndroid Build Coastguard Worker   DEBUG({
2015*9880d681SAndroid Build Coastguard Worker       // Dumps the instruction encoding bits.
2016*9880d681SAndroid Build Coastguard Worker       dumpBits(errs(), Bits);
2017*9880d681SAndroid Build Coastguard Worker 
2018*9880d681SAndroid Build Coastguard Worker       errs() << '\n';
2019*9880d681SAndroid Build Coastguard Worker 
2020*9880d681SAndroid Build Coastguard Worker       // Dumps the list of operand info.
2021*9880d681SAndroid Build Coastguard Worker       for (unsigned i = 0, e = CGI.Operands.size(); i != e; ++i) {
2022*9880d681SAndroid Build Coastguard Worker         const CGIOperandList::OperandInfo &Info = CGI.Operands[i];
2023*9880d681SAndroid Build Coastguard Worker         const std::string &OperandName = Info.Name;
2024*9880d681SAndroid Build Coastguard Worker         const Record &OperandDef = *Info.Rec;
2025*9880d681SAndroid Build Coastguard Worker 
2026*9880d681SAndroid Build Coastguard Worker         errs() << "\t" << OperandName << " (" << OperandDef.getName() << ")\n";
2027*9880d681SAndroid Build Coastguard Worker       }
2028*9880d681SAndroid Build Coastguard Worker     });
2029*9880d681SAndroid Build Coastguard Worker #endif
2030*9880d681SAndroid Build Coastguard Worker 
2031*9880d681SAndroid Build Coastguard Worker   return true;
2032*9880d681SAndroid Build Coastguard Worker }
2033*9880d681SAndroid Build Coastguard Worker 
2034*9880d681SAndroid Build Coastguard Worker // emitFieldFromInstruction - Emit the templated helper function
2035*9880d681SAndroid Build Coastguard Worker // fieldFromInstruction().
emitFieldFromInstruction(formatted_raw_ostream & OS)2036*9880d681SAndroid Build Coastguard Worker static void emitFieldFromInstruction(formatted_raw_ostream &OS) {
2037*9880d681SAndroid Build Coastguard Worker   OS << "// Helper function for extracting fields from encoded instructions.\n"
2038*9880d681SAndroid Build Coastguard Worker      << "template<typename InsnType>\n"
2039*9880d681SAndroid Build Coastguard Worker    << "static InsnType fieldFromInstruction(InsnType insn, unsigned startBit,\n"
2040*9880d681SAndroid Build Coastguard Worker      << "                                     unsigned numBits) {\n"
2041*9880d681SAndroid Build Coastguard Worker      << "    assert(startBit + numBits <= (sizeof(InsnType)*8) &&\n"
2042*9880d681SAndroid Build Coastguard Worker      << "           \"Instruction field out of bounds!\");\n"
2043*9880d681SAndroid Build Coastguard Worker      << "    InsnType fieldMask;\n"
2044*9880d681SAndroid Build Coastguard Worker      << "    if (numBits == sizeof(InsnType)*8)\n"
2045*9880d681SAndroid Build Coastguard Worker      << "      fieldMask = (InsnType)(-1LL);\n"
2046*9880d681SAndroid Build Coastguard Worker      << "    else\n"
2047*9880d681SAndroid Build Coastguard Worker      << "      fieldMask = (((InsnType)1 << numBits) - 1) << startBit;\n"
2048*9880d681SAndroid Build Coastguard Worker      << "    return (insn & fieldMask) >> startBit;\n"
2049*9880d681SAndroid Build Coastguard Worker      << "}\n\n";
2050*9880d681SAndroid Build Coastguard Worker }
2051*9880d681SAndroid Build Coastguard Worker 
2052*9880d681SAndroid Build Coastguard Worker // emitDecodeInstruction - Emit the templated helper function
2053*9880d681SAndroid Build Coastguard Worker // decodeInstruction().
emitDecodeInstruction(formatted_raw_ostream & OS)2054*9880d681SAndroid Build Coastguard Worker static void emitDecodeInstruction(formatted_raw_ostream &OS) {
2055*9880d681SAndroid Build Coastguard Worker   OS << "template<typename InsnType>\n"
2056*9880d681SAndroid Build Coastguard Worker      << "static DecodeStatus decodeInstruction(const uint8_t DecodeTable[], MCInst &MI,\n"
2057*9880d681SAndroid Build Coastguard Worker      << "                                      InsnType insn, uint64_t Address,\n"
2058*9880d681SAndroid Build Coastguard Worker      << "                                      const void *DisAsm,\n"
2059*9880d681SAndroid Build Coastguard Worker      << "                                      const MCSubtargetInfo &STI) {\n"
2060*9880d681SAndroid Build Coastguard Worker      << "  const FeatureBitset& Bits = STI.getFeatureBits();\n"
2061*9880d681SAndroid Build Coastguard Worker      << "\n"
2062*9880d681SAndroid Build Coastguard Worker      << "  const uint8_t *Ptr = DecodeTable;\n"
2063*9880d681SAndroid Build Coastguard Worker      << "  uint32_t CurFieldValue = 0;\n"
2064*9880d681SAndroid Build Coastguard Worker      << "  DecodeStatus S = MCDisassembler::Success;\n"
2065*9880d681SAndroid Build Coastguard Worker      << "  for (;;) {\n"
2066*9880d681SAndroid Build Coastguard Worker      << "    ptrdiff_t Loc = Ptr - DecodeTable;\n"
2067*9880d681SAndroid Build Coastguard Worker      << "    switch (*Ptr) {\n"
2068*9880d681SAndroid Build Coastguard Worker      << "    default:\n"
2069*9880d681SAndroid Build Coastguard Worker      << "      errs() << Loc << \": Unexpected decode table opcode!\\n\";\n"
2070*9880d681SAndroid Build Coastguard Worker      << "      return MCDisassembler::Fail;\n"
2071*9880d681SAndroid Build Coastguard Worker      << "    case MCD::OPC_ExtractField: {\n"
2072*9880d681SAndroid Build Coastguard Worker      << "      unsigned Start = *++Ptr;\n"
2073*9880d681SAndroid Build Coastguard Worker      << "      unsigned Len = *++Ptr;\n"
2074*9880d681SAndroid Build Coastguard Worker      << "      ++Ptr;\n"
2075*9880d681SAndroid Build Coastguard Worker      << "      CurFieldValue = fieldFromInstruction(insn, Start, Len);\n"
2076*9880d681SAndroid Build Coastguard Worker      << "      DEBUG(dbgs() << Loc << \": OPC_ExtractField(\" << Start << \", \"\n"
2077*9880d681SAndroid Build Coastguard Worker      << "                   << Len << \"): \" << CurFieldValue << \"\\n\");\n"
2078*9880d681SAndroid Build Coastguard Worker      << "      break;\n"
2079*9880d681SAndroid Build Coastguard Worker      << "    }\n"
2080*9880d681SAndroid Build Coastguard Worker      << "    case MCD::OPC_FilterValue: {\n"
2081*9880d681SAndroid Build Coastguard Worker      << "      // Decode the field value.\n"
2082*9880d681SAndroid Build Coastguard Worker      << "      unsigned Len;\n"
2083*9880d681SAndroid Build Coastguard Worker      << "      InsnType Val = decodeULEB128(++Ptr, &Len);\n"
2084*9880d681SAndroid Build Coastguard Worker      << "      Ptr += Len;\n"
2085*9880d681SAndroid Build Coastguard Worker      << "      // NumToSkip is a plain 16-bit integer.\n"
2086*9880d681SAndroid Build Coastguard Worker      << "      unsigned NumToSkip = *Ptr++;\n"
2087*9880d681SAndroid Build Coastguard Worker      << "      NumToSkip |= (*Ptr++) << 8;\n"
2088*9880d681SAndroid Build Coastguard Worker      << "\n"
2089*9880d681SAndroid Build Coastguard Worker      << "      // Perform the filter operation.\n"
2090*9880d681SAndroid Build Coastguard Worker      << "      if (Val != CurFieldValue)\n"
2091*9880d681SAndroid Build Coastguard Worker      << "        Ptr += NumToSkip;\n"
2092*9880d681SAndroid Build Coastguard Worker      << "      DEBUG(dbgs() << Loc << \": OPC_FilterValue(\" << Val << \", \" << NumToSkip\n"
2093*9880d681SAndroid Build Coastguard Worker      << "                   << \"): \" << ((Val != CurFieldValue) ? \"FAIL:\" : \"PASS:\")\n"
2094*9880d681SAndroid Build Coastguard Worker      << "                   << \" continuing at \" << (Ptr - DecodeTable) << \"\\n\");\n"
2095*9880d681SAndroid Build Coastguard Worker      << "\n"
2096*9880d681SAndroid Build Coastguard Worker      << "      break;\n"
2097*9880d681SAndroid Build Coastguard Worker      << "    }\n"
2098*9880d681SAndroid Build Coastguard Worker      << "    case MCD::OPC_CheckField: {\n"
2099*9880d681SAndroid Build Coastguard Worker      << "      unsigned Start = *++Ptr;\n"
2100*9880d681SAndroid Build Coastguard Worker      << "      unsigned Len = *++Ptr;\n"
2101*9880d681SAndroid Build Coastguard Worker      << "      InsnType FieldValue = fieldFromInstruction(insn, Start, Len);\n"
2102*9880d681SAndroid Build Coastguard Worker      << "      // Decode the field value.\n"
2103*9880d681SAndroid Build Coastguard Worker      << "      uint32_t ExpectedValue = decodeULEB128(++Ptr, &Len);\n"
2104*9880d681SAndroid Build Coastguard Worker      << "      Ptr += Len;\n"
2105*9880d681SAndroid Build Coastguard Worker      << "      // NumToSkip is a plain 16-bit integer.\n"
2106*9880d681SAndroid Build Coastguard Worker      << "      unsigned NumToSkip = *Ptr++;\n"
2107*9880d681SAndroid Build Coastguard Worker      << "      NumToSkip |= (*Ptr++) << 8;\n"
2108*9880d681SAndroid Build Coastguard Worker      << "\n"
2109*9880d681SAndroid Build Coastguard Worker      << "      // If the actual and expected values don't match, skip.\n"
2110*9880d681SAndroid Build Coastguard Worker      << "      if (ExpectedValue != FieldValue)\n"
2111*9880d681SAndroid Build Coastguard Worker      << "        Ptr += NumToSkip;\n"
2112*9880d681SAndroid Build Coastguard Worker      << "      DEBUG(dbgs() << Loc << \": OPC_CheckField(\" << Start << \", \"\n"
2113*9880d681SAndroid Build Coastguard Worker      << "                   << Len << \", \" << ExpectedValue << \", \" << NumToSkip\n"
2114*9880d681SAndroid Build Coastguard Worker      << "                   << \"): FieldValue = \" << FieldValue << \", ExpectedValue = \"\n"
2115*9880d681SAndroid Build Coastguard Worker      << "                   << ExpectedValue << \": \"\n"
2116*9880d681SAndroid Build Coastguard Worker      << "                   << ((ExpectedValue == FieldValue) ? \"PASS\\n\" : \"FAIL\\n\"));\n"
2117*9880d681SAndroid Build Coastguard Worker      << "      break;\n"
2118*9880d681SAndroid Build Coastguard Worker      << "    }\n"
2119*9880d681SAndroid Build Coastguard Worker      << "    case MCD::OPC_CheckPredicate: {\n"
2120*9880d681SAndroid Build Coastguard Worker      << "      unsigned Len;\n"
2121*9880d681SAndroid Build Coastguard Worker      << "      // Decode the Predicate Index value.\n"
2122*9880d681SAndroid Build Coastguard Worker      << "      unsigned PIdx = decodeULEB128(++Ptr, &Len);\n"
2123*9880d681SAndroid Build Coastguard Worker      << "      Ptr += Len;\n"
2124*9880d681SAndroid Build Coastguard Worker      << "      // NumToSkip is a plain 16-bit integer.\n"
2125*9880d681SAndroid Build Coastguard Worker      << "      unsigned NumToSkip = *Ptr++;\n"
2126*9880d681SAndroid Build Coastguard Worker      << "      NumToSkip |= (*Ptr++) << 8;\n"
2127*9880d681SAndroid Build Coastguard Worker      << "      // Check the predicate.\n"
2128*9880d681SAndroid Build Coastguard Worker      << "      bool Pred;\n"
2129*9880d681SAndroid Build Coastguard Worker      << "      if (!(Pred = checkDecoderPredicate(PIdx, Bits)))\n"
2130*9880d681SAndroid Build Coastguard Worker      << "        Ptr += NumToSkip;\n"
2131*9880d681SAndroid Build Coastguard Worker      << "      (void)Pred;\n"
2132*9880d681SAndroid Build Coastguard Worker      << "      DEBUG(dbgs() << Loc << \": OPC_CheckPredicate(\" << PIdx << \"): \"\n"
2133*9880d681SAndroid Build Coastguard Worker      << "            << (Pred ? \"PASS\\n\" : \"FAIL\\n\"));\n"
2134*9880d681SAndroid Build Coastguard Worker      << "\n"
2135*9880d681SAndroid Build Coastguard Worker      << "      break;\n"
2136*9880d681SAndroid Build Coastguard Worker      << "    }\n"
2137*9880d681SAndroid Build Coastguard Worker      << "    case MCD::OPC_Decode: {\n"
2138*9880d681SAndroid Build Coastguard Worker      << "      unsigned Len;\n"
2139*9880d681SAndroid Build Coastguard Worker      << "      // Decode the Opcode value.\n"
2140*9880d681SAndroid Build Coastguard Worker      << "      unsigned Opc = decodeULEB128(++Ptr, &Len);\n"
2141*9880d681SAndroid Build Coastguard Worker      << "      Ptr += Len;\n"
2142*9880d681SAndroid Build Coastguard Worker      << "      unsigned DecodeIdx = decodeULEB128(Ptr, &Len);\n"
2143*9880d681SAndroid Build Coastguard Worker      << "      Ptr += Len;\n"
2144*9880d681SAndroid Build Coastguard Worker      << "\n"
2145*9880d681SAndroid Build Coastguard Worker      << "      MI.clear();\n"
2146*9880d681SAndroid Build Coastguard Worker      << "      MI.setOpcode(Opc);\n"
2147*9880d681SAndroid Build Coastguard Worker      << "      bool DecodeComplete;\n"
2148*9880d681SAndroid Build Coastguard Worker      << "      S = decodeToMCInst(S, DecodeIdx, insn, MI, Address, DisAsm, DecodeComplete);\n"
2149*9880d681SAndroid Build Coastguard Worker      << "      assert(DecodeComplete);\n"
2150*9880d681SAndroid Build Coastguard Worker      << "\n"
2151*9880d681SAndroid Build Coastguard Worker      << "      DEBUG(dbgs() << Loc << \": OPC_Decode: opcode \" << Opc\n"
2152*9880d681SAndroid Build Coastguard Worker      << "                   << \", using decoder \" << DecodeIdx << \": \"\n"
2153*9880d681SAndroid Build Coastguard Worker      << "                   << (S != MCDisassembler::Fail ? \"PASS\" : \"FAIL\") << \"\\n\");\n"
2154*9880d681SAndroid Build Coastguard Worker      << "      return S;\n"
2155*9880d681SAndroid Build Coastguard Worker      << "    }\n"
2156*9880d681SAndroid Build Coastguard Worker      << "    case MCD::OPC_TryDecode: {\n"
2157*9880d681SAndroid Build Coastguard Worker      << "      unsigned Len;\n"
2158*9880d681SAndroid Build Coastguard Worker      << "      // Decode the Opcode value.\n"
2159*9880d681SAndroid Build Coastguard Worker      << "      unsigned Opc = decodeULEB128(++Ptr, &Len);\n"
2160*9880d681SAndroid Build Coastguard Worker      << "      Ptr += Len;\n"
2161*9880d681SAndroid Build Coastguard Worker      << "      unsigned DecodeIdx = decodeULEB128(Ptr, &Len);\n"
2162*9880d681SAndroid Build Coastguard Worker      << "      Ptr += Len;\n"
2163*9880d681SAndroid Build Coastguard Worker      << "      // NumToSkip is a plain 16-bit integer.\n"
2164*9880d681SAndroid Build Coastguard Worker      << "      unsigned NumToSkip = *Ptr++;\n"
2165*9880d681SAndroid Build Coastguard Worker      << "      NumToSkip |= (*Ptr++) << 8;\n"
2166*9880d681SAndroid Build Coastguard Worker      << "\n"
2167*9880d681SAndroid Build Coastguard Worker      << "      // Perform the decode operation.\n"
2168*9880d681SAndroid Build Coastguard Worker      << "      MCInst TmpMI;\n"
2169*9880d681SAndroid Build Coastguard Worker      << "      TmpMI.setOpcode(Opc);\n"
2170*9880d681SAndroid Build Coastguard Worker      << "      bool DecodeComplete;\n"
2171*9880d681SAndroid Build Coastguard Worker      << "      S = decodeToMCInst(S, DecodeIdx, insn, TmpMI, Address, DisAsm, DecodeComplete);\n"
2172*9880d681SAndroid Build Coastguard Worker      << "      DEBUG(dbgs() << Loc << \": OPC_TryDecode: opcode \" << Opc\n"
2173*9880d681SAndroid Build Coastguard Worker      << "                   << \", using decoder \" << DecodeIdx << \": \");\n"
2174*9880d681SAndroid Build Coastguard Worker      << "\n"
2175*9880d681SAndroid Build Coastguard Worker      << "      if (DecodeComplete) {\n"
2176*9880d681SAndroid Build Coastguard Worker      << "        // Decoding complete.\n"
2177*9880d681SAndroid Build Coastguard Worker      << "        DEBUG(dbgs() << (S != MCDisassembler::Fail ? \"PASS\" : \"FAIL\") << \"\\n\");\n"
2178*9880d681SAndroid Build Coastguard Worker      << "        MI = TmpMI;\n"
2179*9880d681SAndroid Build Coastguard Worker      << "        return S;\n"
2180*9880d681SAndroid Build Coastguard Worker      << "      } else {\n"
2181*9880d681SAndroid Build Coastguard Worker      << "        assert(S == MCDisassembler::Fail);\n"
2182*9880d681SAndroid Build Coastguard Worker      << "        // If the decoding was incomplete, skip.\n"
2183*9880d681SAndroid Build Coastguard Worker      << "        Ptr += NumToSkip;\n"
2184*9880d681SAndroid Build Coastguard Worker      << "        DEBUG(dbgs() << \"FAIL: continuing at \" << (Ptr - DecodeTable) << \"\\n\");\n"
2185*9880d681SAndroid Build Coastguard Worker      << "        // Reset decode status. This also drops a SoftFail status that could be\n"
2186*9880d681SAndroid Build Coastguard Worker      << "        // set before the decode attempt.\n"
2187*9880d681SAndroid Build Coastguard Worker      << "        S = MCDisassembler::Success;\n"
2188*9880d681SAndroid Build Coastguard Worker      << "      }\n"
2189*9880d681SAndroid Build Coastguard Worker      << "      break;\n"
2190*9880d681SAndroid Build Coastguard Worker      << "    }\n"
2191*9880d681SAndroid Build Coastguard Worker      << "    case MCD::OPC_SoftFail: {\n"
2192*9880d681SAndroid Build Coastguard Worker      << "      // Decode the mask values.\n"
2193*9880d681SAndroid Build Coastguard Worker      << "      unsigned Len;\n"
2194*9880d681SAndroid Build Coastguard Worker      << "      InsnType PositiveMask = decodeULEB128(++Ptr, &Len);\n"
2195*9880d681SAndroid Build Coastguard Worker      << "      Ptr += Len;\n"
2196*9880d681SAndroid Build Coastguard Worker      << "      InsnType NegativeMask = decodeULEB128(Ptr, &Len);\n"
2197*9880d681SAndroid Build Coastguard Worker      << "      Ptr += Len;\n"
2198*9880d681SAndroid Build Coastguard Worker      << "      bool Fail = (insn & PositiveMask) || (~insn & NegativeMask);\n"
2199*9880d681SAndroid Build Coastguard Worker      << "      if (Fail)\n"
2200*9880d681SAndroid Build Coastguard Worker      << "        S = MCDisassembler::SoftFail;\n"
2201*9880d681SAndroid Build Coastguard Worker      << "      DEBUG(dbgs() << Loc << \": OPC_SoftFail: \" << (Fail ? \"FAIL\\n\":\"PASS\\n\"));\n"
2202*9880d681SAndroid Build Coastguard Worker      << "      break;\n"
2203*9880d681SAndroid Build Coastguard Worker      << "    }\n"
2204*9880d681SAndroid Build Coastguard Worker      << "    case MCD::OPC_Fail: {\n"
2205*9880d681SAndroid Build Coastguard Worker      << "      DEBUG(dbgs() << Loc << \": OPC_Fail\\n\");\n"
2206*9880d681SAndroid Build Coastguard Worker      << "      return MCDisassembler::Fail;\n"
2207*9880d681SAndroid Build Coastguard Worker      << "    }\n"
2208*9880d681SAndroid Build Coastguard Worker      << "    }\n"
2209*9880d681SAndroid Build Coastguard Worker      << "  }\n"
2210*9880d681SAndroid Build Coastguard Worker      << "  llvm_unreachable(\"bogosity detected in disassembler state machine!\");\n"
2211*9880d681SAndroid Build Coastguard Worker      << "}\n\n";
2212*9880d681SAndroid Build Coastguard Worker }
2213*9880d681SAndroid Build Coastguard Worker 
2214*9880d681SAndroid Build Coastguard Worker // Emits disassembler code for instruction decoding.
run(raw_ostream & o)2215*9880d681SAndroid Build Coastguard Worker void FixedLenDecoderEmitter::run(raw_ostream &o) {
2216*9880d681SAndroid Build Coastguard Worker   formatted_raw_ostream OS(o);
2217*9880d681SAndroid Build Coastguard Worker   OS << "#include \"llvm/MC/MCInst.h\"\n";
2218*9880d681SAndroid Build Coastguard Worker   OS << "#include \"llvm/Support/Debug.h\"\n";
2219*9880d681SAndroid Build Coastguard Worker   OS << "#include \"llvm/Support/DataTypes.h\"\n";
2220*9880d681SAndroid Build Coastguard Worker   OS << "#include \"llvm/Support/LEB128.h\"\n";
2221*9880d681SAndroid Build Coastguard Worker   OS << "#include \"llvm/Support/raw_ostream.h\"\n";
2222*9880d681SAndroid Build Coastguard Worker   OS << "#include <assert.h>\n";
2223*9880d681SAndroid Build Coastguard Worker   OS << '\n';
2224*9880d681SAndroid Build Coastguard Worker   OS << "namespace llvm {\n\n";
2225*9880d681SAndroid Build Coastguard Worker 
2226*9880d681SAndroid Build Coastguard Worker   emitFieldFromInstruction(OS);
2227*9880d681SAndroid Build Coastguard Worker 
2228*9880d681SAndroid Build Coastguard Worker   Target.reverseBitsForLittleEndianEncoding();
2229*9880d681SAndroid Build Coastguard Worker 
2230*9880d681SAndroid Build Coastguard Worker   // Parameterize the decoders based on namespace and instruction width.
2231*9880d681SAndroid Build Coastguard Worker   NumberedInstructions = Target.getInstructionsByEnumValue();
2232*9880d681SAndroid Build Coastguard Worker   std::map<std::pair<std::string, unsigned>,
2233*9880d681SAndroid Build Coastguard Worker            std::vector<unsigned> > OpcMap;
2234*9880d681SAndroid Build Coastguard Worker   std::map<unsigned, std::vector<OperandInfo> > Operands;
2235*9880d681SAndroid Build Coastguard Worker 
2236*9880d681SAndroid Build Coastguard Worker   for (unsigned i = 0; i < NumberedInstructions.size(); ++i) {
2237*9880d681SAndroid Build Coastguard Worker     const CodeGenInstruction *Inst = NumberedInstructions[i];
2238*9880d681SAndroid Build Coastguard Worker     const Record *Def = Inst->TheDef;
2239*9880d681SAndroid Build Coastguard Worker     unsigned Size = Def->getValueAsInt("Size");
2240*9880d681SAndroid Build Coastguard Worker     if (Def->getValueAsString("Namespace") == "TargetOpcode" ||
2241*9880d681SAndroid Build Coastguard Worker         Def->getValueAsBit("isPseudo") ||
2242*9880d681SAndroid Build Coastguard Worker         Def->getValueAsBit("isAsmParserOnly") ||
2243*9880d681SAndroid Build Coastguard Worker         Def->getValueAsBit("isCodeGenOnly"))
2244*9880d681SAndroid Build Coastguard Worker       continue;
2245*9880d681SAndroid Build Coastguard Worker 
2246*9880d681SAndroid Build Coastguard Worker     std::string DecoderNamespace = Def->getValueAsString("DecoderNamespace");
2247*9880d681SAndroid Build Coastguard Worker 
2248*9880d681SAndroid Build Coastguard Worker     if (Size) {
2249*9880d681SAndroid Build Coastguard Worker       if (populateInstruction(Target, *Inst, i, Operands)) {
2250*9880d681SAndroid Build Coastguard Worker         OpcMap[std::make_pair(DecoderNamespace, Size)].push_back(i);
2251*9880d681SAndroid Build Coastguard Worker       }
2252*9880d681SAndroid Build Coastguard Worker     }
2253*9880d681SAndroid Build Coastguard Worker   }
2254*9880d681SAndroid Build Coastguard Worker 
2255*9880d681SAndroid Build Coastguard Worker   DecoderTableInfo TableInfo;
2256*9880d681SAndroid Build Coastguard Worker   for (const auto &Opc : OpcMap) {
2257*9880d681SAndroid Build Coastguard Worker     // Emit the decoder for this namespace+width combination.
2258*9880d681SAndroid Build Coastguard Worker     FilterChooser FC(NumberedInstructions, Opc.second, Operands,
2259*9880d681SAndroid Build Coastguard Worker                      8*Opc.first.second, this);
2260*9880d681SAndroid Build Coastguard Worker 
2261*9880d681SAndroid Build Coastguard Worker     // The decode table is cleared for each top level decoder function. The
2262*9880d681SAndroid Build Coastguard Worker     // predicates and decoders themselves, however, are shared across all
2263*9880d681SAndroid Build Coastguard Worker     // decoders to give more opportunities for uniqueing.
2264*9880d681SAndroid Build Coastguard Worker     TableInfo.Table.clear();
2265*9880d681SAndroid Build Coastguard Worker     TableInfo.FixupStack.clear();
2266*9880d681SAndroid Build Coastguard Worker     TableInfo.Table.reserve(16384);
2267*9880d681SAndroid Build Coastguard Worker     TableInfo.FixupStack.emplace_back();
2268*9880d681SAndroid Build Coastguard Worker     FC.emitTableEntries(TableInfo);
2269*9880d681SAndroid Build Coastguard Worker     // Any NumToSkip fixups in the top level scope can resolve to the
2270*9880d681SAndroid Build Coastguard Worker     // OPC_Fail at the end of the table.
2271*9880d681SAndroid Build Coastguard Worker     assert(TableInfo.FixupStack.size() == 1 && "fixup stack phasing error!");
2272*9880d681SAndroid Build Coastguard Worker     // Resolve any NumToSkip fixups in the current scope.
2273*9880d681SAndroid Build Coastguard Worker     resolveTableFixups(TableInfo.Table, TableInfo.FixupStack.back(),
2274*9880d681SAndroid Build Coastguard Worker                        TableInfo.Table.size());
2275*9880d681SAndroid Build Coastguard Worker     TableInfo.FixupStack.clear();
2276*9880d681SAndroid Build Coastguard Worker 
2277*9880d681SAndroid Build Coastguard Worker     TableInfo.Table.push_back(MCD::OPC_Fail);
2278*9880d681SAndroid Build Coastguard Worker 
2279*9880d681SAndroid Build Coastguard Worker     // Print the table to the output stream.
2280*9880d681SAndroid Build Coastguard Worker     emitTable(OS, TableInfo.Table, 0, FC.getBitWidth(), Opc.first.first);
2281*9880d681SAndroid Build Coastguard Worker     OS.flush();
2282*9880d681SAndroid Build Coastguard Worker   }
2283*9880d681SAndroid Build Coastguard Worker 
2284*9880d681SAndroid Build Coastguard Worker   // Emit the predicate function.
2285*9880d681SAndroid Build Coastguard Worker   emitPredicateFunction(OS, TableInfo.Predicates, 0);
2286*9880d681SAndroid Build Coastguard Worker 
2287*9880d681SAndroid Build Coastguard Worker   // Emit the decoder function.
2288*9880d681SAndroid Build Coastguard Worker   emitDecoderFunction(OS, TableInfo.Decoders, 0);
2289*9880d681SAndroid Build Coastguard Worker 
2290*9880d681SAndroid Build Coastguard Worker   // Emit the main entry point for the decoder, decodeInstruction().
2291*9880d681SAndroid Build Coastguard Worker   emitDecodeInstruction(OS);
2292*9880d681SAndroid Build Coastguard Worker 
2293*9880d681SAndroid Build Coastguard Worker   OS << "\n} // End llvm namespace\n";
2294*9880d681SAndroid Build Coastguard Worker }
2295*9880d681SAndroid Build Coastguard Worker 
2296*9880d681SAndroid Build Coastguard Worker namespace llvm {
2297*9880d681SAndroid Build Coastguard Worker 
EmitFixedLenDecoder(RecordKeeper & RK,raw_ostream & OS,const std::string & PredicateNamespace,const std::string & GPrefix,const std::string & GPostfix,const std::string & ROK,const std::string & RFail,const std::string & L)2298*9880d681SAndroid Build Coastguard Worker void EmitFixedLenDecoder(RecordKeeper &RK, raw_ostream &OS,
2299*9880d681SAndroid Build Coastguard Worker                          const std::string &PredicateNamespace,
2300*9880d681SAndroid Build Coastguard Worker                          const std::string &GPrefix,
2301*9880d681SAndroid Build Coastguard Worker                          const std::string &GPostfix, const std::string &ROK,
2302*9880d681SAndroid Build Coastguard Worker                          const std::string &RFail, const std::string &L) {
2303*9880d681SAndroid Build Coastguard Worker   FixedLenDecoderEmitter(RK, PredicateNamespace, GPrefix, GPostfix,
2304*9880d681SAndroid Build Coastguard Worker                          ROK, RFail, L).run(OS);
2305*9880d681SAndroid Build Coastguard Worker }
2306*9880d681SAndroid Build Coastguard Worker 
2307*9880d681SAndroid Build Coastguard Worker } // End llvm namespace
2308