Home | History | Annotate | Download | only in X86
      1 ; This test is attempting to detect when we request forced re-alignment of the
      2 ; stack to an alignment greater than would be available due to the ABI. We
      3 ; arbitrarily force alignment up to 32-bytes for i386 hoping that this will
      4 ; exceed any ABI provisions.
      5 ;
      6 ; RUN: llc < %s -mcpu=generic -force-align-stack -stack-alignment=32 | FileCheck %s
      7 
      8 target 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 target triple = "i386-unknown-linux-gnu"
     10 
     11 define i32 @f(i8* %p) nounwind {
     12 entry:
     13   %0 = load i8, i8* %p
     14   %conv = sext i8 %0 to i32
     15   ret i32 %conv
     16 }
     17 
     18 define i64 @g(i32 %i) nounwind {
     19 ; CHECK-LABEL: g:
     20 ; CHECK:      pushl  %ebp
     21 ; CHECK-NEXT: movl   %esp, %ebp
     22 ; CHECK-NEXT: pushl
     23 ; CHECK-NEXT: pushl
     24 ; CHECK-NEXT: andl   $-32, %esp
     25 ; CHECK-NEXT: subl   $32, %esp
     26 ;
     27 ; Now setup the base pointer (%esi).
     28 ; CHECK-NEXT: movl   %esp, %esi
     29 ; CHECK-NOT:         {{[^ ,]*}}, %esp
     30 ;
     31 ; The next adjustment of the stack is due to the alloca.
     32 ; CHECK:      movl   %{{...}}, %esp
     33 ; CHECK-NOT:         {{[^ ,]*}}, %esp
     34 ;
     35 ; Next we set up the memset call, and then undo it.
     36 ; CHECK:      subl   $20, %esp
     37 ; CHECK-NOT:         {{[^ ,]*}}, %esp
     38 ; CHECK:      calll  memset
     39 ; CHECK-NEXT: addl   $32, %esp
     40 ; CHECK-NOT:         {{[^ ,]*}}, %esp
     41 ;
     42 ; Next we set up the call to 'f'.
     43 ; CHECK:      subl   $28, %esp
     44 ; CHECK-NOT:         {{[^ ,]*}}, %esp
     45 ; CHECK:      calll  f
     46 ; CHECK-NEXT: addl   $32, %esp
     47 ; CHECK-NOT:         {{[^ ,]*}}, %esp
     48 ;
     49 ; Restore %esp from %ebp (frame pointer) and subtract the size of
     50 ; zone with callee-saved registers to pop them.
     51 ; This is the state prior to stack realignment and the allocation of VLAs.
     52 ; CHECK-NOT:  popl
     53 ; CHECK:      leal   -8(%ebp), %esp
     54 ; CHECK-NEXT: popl
     55 ; CHECK-NEXT: popl
     56 ; CHECK-NEXT: popl   %ebp
     57 ; CHECK-NEXT: ret
     58 
     59 entry:
     60   br label %if.then
     61 
     62 if.then:
     63   %0 = alloca i8, i32 %i
     64   call void @llvm.memset.p0i8.i32(i8* %0, i8 0, i32 %i, i32 1, i1 false)
     65   %call = call i32 @f(i8* %0)
     66   %conv = sext i32 %call to i64
     67   ret i64 %conv
     68 }
     69 
     70 declare void @llvm.memset.p0i8.i32(i8*, i8, i32, i32, i1) nounwind
     71