test/CodeGen/X86/win32_sret.ll

; We specify -mcpu explicitly to avoid instruction reordering that happens on
; some setups (e.g., Atom) from affecting the output.
; RUN: llc < %s -mcpu=core2 -mtriple=i686-pc-win32 | FileCheck %s -check-prefix=WIN32
; RUN: llc < %s -mtriple=i686-pc-mingw32 | FileCheck %s -check-prefix=MINGW_X86
; RUN: llc < %s -mtriple=i386-pc-linux | FileCheck %s -check-prefix=LINUX
; RUN: llc < %s -mcpu=core2 -O0 -mtriple=i686-pc-win32 | FileCheck %s -check-prefix=WIN32
; RUN: llc < %s -O0 -mtriple=i686-pc-mingw32 | FileCheck %s -check-prefix=MINGW_X86
; RUN: llc < %s -O0 -mtriple=i386-pc-linux | FileCheck %s -check-prefix=LINUX

; The SysV ABI used by most Unixes and Mingw on x86 specifies that an sret pointer
; is callee-cleanup. However, in MSVC's cdecl calling convention, sret pointer
; arguments are caller-cleanup like normal arguments.

define void @sret1(i8* sret %x) nounwind {
entry:
; WIN32:      sret1
; WIN32:      movb $42, (%eax)
; WIN32-NOT:  popl %eax
; WIN32:    {{ret$}}

; MINGW_X86:  sret1
; MINGW_X86:  ret $4

; LINUX:      sret1
; LINUX:      ret $4

  store i8 42, i8* %x, align 4
  ret void
}

define void @sret2(i8* sret %x, i8 %y) nounwind {
entry:
; WIN32:      sret2
; WIN32:      movb {{.*}}, (%eax)
; WIN32-NOT:  popl %eax
; WIN32:    {{ret$}}

; MINGW_X86:  sret2
; MINGW_X86:  ret $4

; LINUX:      sret2
; LINUX:      ret $4

  store i8 %y, i8* %x
  ret void
}

define void @sret3(i8* sret %x, i8* %y) nounwind {
entry:
; WIN32:      sret3
; WIN32:      movb $42, (%eax)
; WIN32-NOT:  movb $13, (%eax)
; WIN32-NOT:  popl %eax
; WIN32:    {{ret$}}

; MINGW_X86:  sret3
; MINGW_X86:  ret $4

; LINUX:      sret3
; LINUX:      ret $4

  store i8 42, i8* %x
  store i8 13, i8* %y
  ret void
}

; PR15556
%struct.S4 = type { i32, i32, i32 }

define void @sret4(%struct.S4* noalias sret %agg.result) {
entry:
; WIN32:     sret4
; WIN32:     movl $42, (%eax)
; WIN32-NOT: popl %eax
; WIN32:   {{ret$}}

; MINGW_X86: sret4
; MINGW_X86: ret $4

; LINUX:     sret4
; LINUX:     ret $4

  %x = getelementptr inbounds %struct.S4* %agg.result, i32 0, i32 0
  store i32 42, i32* %x, align 4
  ret void
}

%struct.S5 = type { i32 }
%class.C5 = type { i8 }

define x86_thiscallcc void @"\01?foo@C5@@QAE?AUS5@@XZ"(%struct.S5* noalias sret %agg.result, %class.C5* %this) {
entry:
  %this.addr = alloca %class.C5*, align 4
  store %class.C5* %this, %class.C5** %this.addr, align 4
  %this1 = load %class.C5** %this.addr
  %x = getelementptr inbounds %struct.S5* %agg.result, i32 0, i32 0
  store i32 42, i32* %x, align 4
  ret void
; WIN32:     {{^}}"?foo@C5@@QAE?AUS5@@XZ":

; The address of the return structure is passed as an implicit parameter.
; In the -O0 build, %eax is spilled at the beginning of the function, hence we
; should match both 4(%esp) and 8(%esp).
; WIN32:     {{[48]}}(%esp), %eax
; WIN32:     movl $42, (%eax)
; WIN32:     ret $4
}

define void @call_foo5() {
entry:
  %c = alloca %class.C5, align 1
  %s = alloca %struct.S5, align 4
  call x86_thiscallcc void @"\01?foo@C5@@QAE?AUS5@@XZ"(%struct.S5* sret %s, %class.C5* %c)
; WIN32:      {{^}}_call_foo5:

; Load the address of the result and put it onto stack
; (through %ecx in the -O0 build).
; WIN32:      leal {{[0-9]+}}(%esp), %e{{[a-d]}}x
; WIN32:      movl %e{{[a-d]}}x, (%e{{([a-d]x)|(sp)}})

; The this pointer goes to ECX.
; WIN32-NEXT: leal {{[0-9]+}}(%esp), %ecx
; WIN32-NEXT: calll "?foo@C5@@QAE?AUS5@@XZ"
; WIN32:      ret
  ret void
}