xref: /aosp_15_r20/external/pytorch/torch/csrc/jit/tensorexpr/cpp_codegen.h (revision da0073e96a02ea20f0ac840b70461e3646d07c45)
1 #pragma once
2 
3 #include <torch/csrc/jit/tensorexpr/codegen.h>
4 #include <torch/csrc/jit/tensorexpr/ir_printer.h>
5 
6 namespace torch::jit::tensorexpr {
7 
8 class CppVarNameRewriter;
9 
10 // Generates C++ code from the IR.
11 //
12 // Vector operations are unrolled.
13 // For example:
14 // C[Ramp(0, 1, 3)] = A[Ramp(0, 2, 3)] + B[Ramp(0, 3, 3)];
15 // is unrolled into:
16 // C[0] = A[0] + B[0];
17 // C[1] = A[2] + B[3];
18 // C[2] = A[4] + B[6];
19 class TORCH_API CppPrinter : public IRPrinter {
20  public:
21   explicit CppPrinter(std::ostream* os);
22   ~CppPrinter() override;
23 
24   void printPrologue();
25 
26   using IRPrinter::visit;
27 
28   // Binary expressions.
29   void visit(const ModPtr&) override;
30   void visit(const MaxPtr&) override;
31   void visit(const MinPtr&) override;
32 
33   // Conditional expressions.
34   void visit(const CompareSelectPtr&) override;
35   void visit(const IfThenElsePtr&) override;
36 
37   // Tensor operations.
38   void visit(const AllocatePtr&) override;
39   void visit(const FreePtr&) override;
40   void visit(const LoadPtr&) override;
41   void visit(const StorePtr&) override;
42 
43   // Casts.
44   void visit(const CastPtr&) override;
45   void visit(const BitCastPtr&) override;
46 
47   // Calls.
48   void visit(const IntrinsicsPtr&) override;
49   void visit(const ExternalCallPtr&) override;
50 
51   // Vars.
52   void visit(const LetPtr&) override;
53   void visit(const VarPtr&) override;
54 
55   // Vector data types.
56   void visit(const RampPtr&) override;
57   void visit(const BroadcastPtr&) override;
58 
59  private:
60   int lane_;
61   std::unordered_map<VarPtr, ExprPtr> vector_vars_;
62 };
63 
64 class TORCH_API CppCodeGen : public CodeGen {
65  public:
66   CppCodeGen(
67       StmtPtr stmt,
68       const std::vector<BufferArg>& buffer_args,
69       at::Device device = at::kCPU,
70       const std::string& kernel_func_name = "func");
71 
72   ~CppCodeGen() override;
73 
74   void call(const std::vector<CallArg>& args) override;
75   void call_raw(const std::vector<void*>& args) override;
76 
77   template <typename... Ts>
operator()78   void operator()(const Ts&... ts) {
79     call(std::vector<CallArg>({CallArg(ts)...}));
80   }
81 
82   std::string getCodeText(const std::string& attr = "") override {
83     return oss_.str();
84   }
85 
86  private:
87   void init();
88 
os()89   std::ostream& os() {
90     return printer_->os();
91   }
92 
93   std::ostringstream oss_;
94   std::unique_ptr<CppPrinter> printer_;
95   std::unique_ptr<CppVarNameRewriter> var_name_rewriter_;
96 };
97 
98 } // namespace torch::jit::tensorexpr
99