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|
; This test is attempting to detect when we request forced re-alignment of the
; stack to an alignment greater than would be available due to the ABI. We
; arbitrarily force alignment up to 32-bytes for i386 hoping that this will
; exceed any ABI provisions.
;
; RUN: llc < %s -mcpu=generic -stackrealign | FileCheck %s
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"
target triple = "i386-unknown-linux-gnu"
define i32 @f(i8* %p) nounwind {
entry:
%0 = load i8, i8* %p
%conv = sext i8 %0 to i32
ret i32 %conv
}
define i64 @g(i32 %i) nounwind {
; CHECK-LABEL: g:
; CHECK: pushl %ebp
; CHECK-NEXT: movl %esp, %ebp
; CHECK-NEXT: pushl
; CHECK-NEXT: pushl
; CHECK-NEXT: andl $-32, %esp
; CHECK-NEXT: subl $32, %esp
;
; Now setup the base pointer (%esi).
; CHECK-NEXT: movl %esp, %esi
; CHECK-NOT: {{[^ ,]*}}, %esp
;
; The next adjustment of the stack is due to the alloca.
; CHECK: movl %{{...}}, %esp
; CHECK-NOT: {{[^ ,]*}}, %esp
;
; Next we set up the memset call.
; CHECK: subl $20, %esp
; CHECK-NOT: {{[^ ,]*}}, %esp
; CHECK: pushl
; CHECK: pushl
; CHECK: pushl
; CHECK: calll memset
;
; Deallocating 32 bytes of outgoing call frame for memset and
; allocating 28 bytes for calling f yields a 4-byte adjustment:
; CHECK-NEXT: addl $4, %esp
; CHECK-NOT: {{[^ ,]*}}, %esp
;
; And move on to call 'f', and then restore the stack.
; CHECK: pushl
; CHECK-NOT: {{[^ ,]*}}, %esp
; CHECK: calll f
; CHECK-NEXT: addl $32, %esp
; CHECK-NOT: {{[^ ,]*}}, %esp
;
; Restore %esp from %ebp (frame pointer) and subtract the size of
; zone with callee-saved registers to pop them.
; This is the state prior to stack realignment and the allocation of VLAs.
; CHECK-NOT: popl
; CHECK: leal -8(%ebp), %esp
; CHECK-NEXT: popl
; CHECK-NEXT: popl
; CHECK-NEXT: popl %ebp
; CHECK-NEXT: ret
entry:
br label %if.then
if.then:
%0 = alloca i8, i32 %i
call void @llvm.memset.p0i8.i32(i8* %0, i8 0, i32 %i, i1 false)
%call = call i32 @f(i8* %0)
%conv = sext i32 %call to i64
ret i64 %conv
}
declare void @llvm.memset.p0i8.i32(i8*, i8, i32, i1) nounwind
!llvm.module.flags = !{!0}
!0 = !{i32 2, !"override-stack-alignment", i32 32}
|
