llvm/test/CodeGen/X86/win_chkstk.ll
2011-01-06 01:09:35 +00:00

47 lines
1.7 KiB
LLVM

; RUN: llc < %s -mtriple=i686-pc-win32 | FileCheck %s -check-prefix=WIN_X32
; RUN: llc < %s -mtriple=x86_64-pc-win32 | FileCheck %s -check-prefix=WIN_X64
; RUN: llc < %s -mtriple=i686-pc-mingw32 | FileCheck %s -check-prefix=MINGW_X32
; RUN: llc < %s -mtriple=x86_64-pc-mingw32 | FileCheck %s -check-prefix=MINGW_X64
; RUN: llc < %s -mtriple=i386-pc-linux | FileCheck %s -check-prefix=LINUX
; Windows and mingw require a prologue helper routine if more than 4096 bytes area
; allocated on the stack. Windows uses __chkstk and mingw uses __alloca. __alloca
; and the 32-bit version of __chkstk will probe the stack and adjust the stack pointer.
; The 64-bit version of __chkstk is only responsible for probing the stack. The 64-bit
; prologue is responsible for adjusting the stack pointer.
; Stack allocation >= 4096 bytes will require call to __chkstk in the Windows ABI.
define i32 @main4k() nounwind {
entry:
; WIN_X32: calll __chkstk
; WIN_X64: callq __chkstk
; MINGW_X32: calll __alloca
; MINGW_X64: callq __chkstk
; LINUX-NOT: call __chkstk
%array4096 = alloca [4096 x i8], align 16 ; <[4096 x i8]*> [#uses=0]
ret i32 0
}
; Make sure we don't call __chkstk or __alloca when we have less than a 4096 stack
; allocation.
define i32 @main128() nounwind {
entry:
; WIN_X32: # BB#0:
; WIN_X32-NOT: calll __chkstk
; WIN_X32: ret
; WIN_X64: # BB#0:
; WIN_X64-NOT: callq __chkstk
; WIN_X64: ret
; MINGW_X64: # BB#0:
; MINGW_X64-NOT: callq _alloca
; MINGW_X64: ret
; LINUX: # BB#0:
; LINUX-NOT: call __chkstk
; LINUX: ret
%array128 = alloca [128 x i8], align 16 ; <[128 x i8]*> [#uses=0]
ret i32 0
}