xref: /aosp_15_r20/external/llvm/test/CodeGen/X86/force-align-stack-alloca.ll (revision 9880d6810fe72a1726cb53787c6711e909410d58)
1*9880d681SAndroid Build Coastguard Worker; This test is attempting to detect when we request forced re-alignment of the
2*9880d681SAndroid Build Coastguard Worker; stack to an alignment greater than would be available due to the ABI. We
3*9880d681SAndroid Build Coastguard Worker; arbitrarily force alignment up to 32-bytes for i386 hoping that this will
4*9880d681SAndroid Build Coastguard Worker; exceed any ABI provisions.
5*9880d681SAndroid Build Coastguard Worker;
6*9880d681SAndroid Build Coastguard Worker; RUN: llc < %s -mcpu=generic -stackrealign -stack-alignment=32 | FileCheck %s
7*9880d681SAndroid Build Coastguard Worker
8*9880d681SAndroid Build Coastguard Workertarget datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32-S128"
9*9880d681SAndroid Build Coastguard Workertarget triple = "i386-unknown-linux-gnu"
10*9880d681SAndroid Build Coastguard Worker
11*9880d681SAndroid Build Coastguard Workerdefine i32 @f(i8* %p) nounwind {
12*9880d681SAndroid Build Coastguard Workerentry:
13*9880d681SAndroid Build Coastguard Worker  %0 = load i8, i8* %p
14*9880d681SAndroid Build Coastguard Worker  %conv = sext i8 %0 to i32
15*9880d681SAndroid Build Coastguard Worker  ret i32 %conv
16*9880d681SAndroid Build Coastguard Worker}
17*9880d681SAndroid Build Coastguard Worker
18*9880d681SAndroid Build Coastguard Workerdefine i64 @g(i32 %i) nounwind {
19*9880d681SAndroid Build Coastguard Worker; CHECK-LABEL: g:
20*9880d681SAndroid Build Coastguard Worker; CHECK:      pushl  %ebp
21*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: movl   %esp, %ebp
22*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: pushl
23*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: pushl
24*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: andl   $-32, %esp
25*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: subl   $32, %esp
26*9880d681SAndroid Build Coastguard Worker;
27*9880d681SAndroid Build Coastguard Worker; Now setup the base pointer (%esi).
28*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: movl   %esp, %esi
29*9880d681SAndroid Build Coastguard Worker; CHECK-NOT:         {{[^ ,]*}}, %esp
30*9880d681SAndroid Build Coastguard Worker;
31*9880d681SAndroid Build Coastguard Worker; The next adjustment of the stack is due to the alloca.
32*9880d681SAndroid Build Coastguard Worker; CHECK:      movl   %{{...}}, %esp
33*9880d681SAndroid Build Coastguard Worker; CHECK-NOT:         {{[^ ,]*}}, %esp
34*9880d681SAndroid Build Coastguard Worker;
35*9880d681SAndroid Build Coastguard Worker; Next we set up the memset call.
36*9880d681SAndroid Build Coastguard Worker; CHECK:      subl   $20, %esp
37*9880d681SAndroid Build Coastguard Worker; CHECK-NOT:         {{[^ ,]*}}, %esp
38*9880d681SAndroid Build Coastguard Worker; CHECK:      pushl
39*9880d681SAndroid Build Coastguard Worker; CHECK:      pushl
40*9880d681SAndroid Build Coastguard Worker; CHECK:      pushl
41*9880d681SAndroid Build Coastguard Worker; CHECK:      calll  memset
42*9880d681SAndroid Build Coastguard Worker;
43*9880d681SAndroid Build Coastguard Worker; Deallocating 32 bytes of outgoing call frame for memset and
44*9880d681SAndroid Build Coastguard Worker; allocating 28 bytes for calling f yields a 4-byte adjustment:
45*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: addl   $4, %esp
46*9880d681SAndroid Build Coastguard Worker; CHECK-NOT:         {{[^ ,]*}}, %esp
47*9880d681SAndroid Build Coastguard Worker;
48*9880d681SAndroid Build Coastguard Worker; And move on to call 'f', and then restore the stack.
49*9880d681SAndroid Build Coastguard Worker; CHECK:      pushl
50*9880d681SAndroid Build Coastguard Worker; CHECK-NOT:         {{[^ ,]*}}, %esp
51*9880d681SAndroid Build Coastguard Worker; CHECK:      calll  f
52*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: addl   $32, %esp
53*9880d681SAndroid Build Coastguard Worker; CHECK-NOT:         {{[^ ,]*}}, %esp
54*9880d681SAndroid Build Coastguard Worker;
55*9880d681SAndroid Build Coastguard Worker; Restore %esp from %ebp (frame pointer) and subtract the size of
56*9880d681SAndroid Build Coastguard Worker; zone with callee-saved registers to pop them.
57*9880d681SAndroid Build Coastguard Worker; This is the state prior to stack realignment and the allocation of VLAs.
58*9880d681SAndroid Build Coastguard Worker; CHECK-NOT:  popl
59*9880d681SAndroid Build Coastguard Worker; CHECK:      leal   -8(%ebp), %esp
60*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: popl
61*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: popl
62*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: popl   %ebp
63*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: ret
64*9880d681SAndroid Build Coastguard Worker
65*9880d681SAndroid Build Coastguard Workerentry:
66*9880d681SAndroid Build Coastguard Worker  br label %if.then
67*9880d681SAndroid Build Coastguard Worker
68*9880d681SAndroid Build Coastguard Workerif.then:
69*9880d681SAndroid Build Coastguard Worker  %0 = alloca i8, i32 %i
70*9880d681SAndroid Build Coastguard Worker  call void @llvm.memset.p0i8.i32(i8* %0, i8 0, i32 %i, i32 1, i1 false)
71*9880d681SAndroid Build Coastguard Worker  %call = call i32 @f(i8* %0)
72*9880d681SAndroid Build Coastguard Worker  %conv = sext i32 %call to i64
73*9880d681SAndroid Build Coastguard Worker  ret i64 %conv
74*9880d681SAndroid Build Coastguard Worker}
75*9880d681SAndroid Build Coastguard Worker
76*9880d681SAndroid Build Coastguard Workerdeclare void @llvm.memset.p0i8.i32(i8*, i8, i32, i32, i1) nounwind
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