1; RUN: llc < %s -mtriple=i686-pc-win32 | FileCheck %s -check-prefix=WIN_X32 2; RUN: llc < %s -mtriple=x86_64-pc-win32 | FileCheck %s -check-prefix=WIN_X64 3; RUN: llc < %s -mtriple=x86_64-pc-win32 -code-model=large | FileCheck %s -check-prefix=WIN64_LARGE 4; RUN: llc < %s -mtriple=i686-pc-mingw32 | FileCheck %s -check-prefix=MINGW_X32 5; RUN: llc < %s -mtriple=x86_64-pc-mingw32 | FileCheck %s -check-prefix=MINGW_X64 6; RUN: llc < %s -mtriple=i386-pc-linux | FileCheck %s -check-prefix=LINUX 7; RUN: llc < %s -mtriple=x86_64-pc-win32-macho | FileCheck %s -check-prefix=LINUX 8 9; Windows and mingw require a prologue helper routine if more than 4096 bytes area 10; allocated on the stack. Windows uses __chkstk and mingw uses __alloca. __alloca 11; and the 32-bit version of __chkstk will probe the stack and adjust the stack pointer. 12; The 64-bit version of __chkstk is only responsible for probing the stack. The 64-bit 13; prologue is responsible for adjusting the stack pointer. 14 15; Stack allocation >= 4096 bytes will require call to __chkstk in the Windows ABI. 16define i32 @main4k() nounwind { 17entry: 18; WIN_X32: calll __chkstk 19; WIN_X64: callq __chkstk 20; WIN64_LARGE: movabsq $__chkstk, %r11 21; WIN64_LARGE: callq *%r11 22; MINGW_X32: calll __alloca 23; MINGW_X64: callq ___chkstk_ms 24; LINUX-NOT: call __chkstk 25 %array4096 = alloca [4096 x i8], align 16 ; <[4096 x i8]*> [#uses=0] 26 ret i32 0 27} 28 29; Make sure we don't call __chkstk or __alloca when we have less than a 4096 stack 30; allocation. 31define i32 @main128() nounwind { 32entry: 33; WIN_X32: # %bb.0: 34; WIN_X32-NOT: calll __chkstk 35; WIN_X32: ret 36 37; WIN_X64: # %bb.0: 38; WIN_X64-NOT: callq __chkstk 39; WIN_X64: ret 40 41; MINGW_X64: # %bb.0: 42; MINGW_X64-NOT: callq ___chkstk_ms 43; MINGW_X64: ret 44 45; LINUX: # %bb.0: 46; LINUX-NOT: call __chkstk 47; LINUX: ret 48 %array128 = alloca [128 x i8], align 16 ; <[128 x i8]*> [#uses=0] 49 ret i32 0 50} 51 52; Make sure we don't call __chkstk or __alloca on non-Windows even if the 53; caller has the Win64 calling convention. 54define win64cc i32 @main4k_win64() nounwind { 55entry: 56; WIN_X32: calll __chkstk 57; WIN_X64: callq __chkstk 58; WIN64_LARGE: movabsq $__chkstk, %r11 59; WIN64_LARGE: callq *%r11 60; MINGW_X32: calll __alloca 61; MINGW_X64: callq ___chkstk_ms 62; LINUX-NOT: call __chkstk 63 %array4096 = alloca [4096 x i8], align 16 ; <[4096 x i8]*> [#uses=0] 64 ret i32 0 65} 66 67; PR30687: Avoid crashing when inserting a __chkstk call at the end of an MBB. 68define void @dont_crash() { 69entry: 70; WIN_X32: calll __chkstk 71; WIN_X64: callq __chkstk 72; WIN64_LARGE: movabsq $__chkstk, %r11 73; WIN64_LARGE: callq *%r11 74; MINGW_X32: calll __alloca 75; MINGW_X64: callq ___chkstk_ms 76; LINUX-NOT: call __chkstk 77 %buffer = alloca [4096 x i8] 78 br label %ret 79 80ret: 81 ret void 82} 83