llvm-6502/test/CodeGen/X86/2012-08-07-CmpISelBug.ll
Evan Cheng b64dd5f2b5 X86 cmp lowering is looking past truncate on the condition node. It should only
do so when the high bits are known zero. This caused a subtle miscompilation.

rdar://12027825 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161451 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-07 22:21:00 +00:00

37 lines
1.1 KiB
LLVM

; RUN: llc < %s -mtriple=x86_64-apple-macosx | FileCheck %s
; Cmp lowering should not look past the truncate unless the high bits are known
; zero.
; rdar://12027825
define void @foo(i8 %arg4, i32 %arg5, i32* %arg14) nounwind {
bb:
; CHECK: foo:
; CHECK-NOT: testl
; CHECK: testb
%tmp48 = zext i8 %arg4 to i32
%tmp49 = and i32 %tmp48, 32
%tmp50 = add i32 %tmp49, 1593371643
%tmp55 = sub i32 %tmp50, 0
%tmp56 = add i32 %tmp55, 7787538
%tmp57 = xor i32 %tmp56, 1601159181
%tmp58 = xor i32 %arg5, 1601159181
%tmp59 = and i32 %tmp57, %tmp58
%tmp60 = add i32 %tmp59, -1263900958
%tmp67 = sub i32 %tmp60, 0
%tmp103 = xor i32 %tmp56, 13
%tmp104 = trunc i32 %tmp103 to i8
%tmp105 = sub i8 0, %tmp104
%tmp106 = add i8 %tmp105, -103
%tmp113 = sub i8 %tmp106, 0
%tmp114 = add i8 %tmp113, -72
%tmp141 = icmp ne i32 %tmp67, -1263900958
%tmp142 = select i1 %tmp141, i8 %tmp114, i8 undef
%tmp143 = xor i8 %tmp142, 81
%tmp144 = zext i8 %tmp143 to i32
%tmp145 = add i32 %tmp144, 2062143348
%tmp152 = sub i32 %tmp145, 0
store i32 %tmp152, i32* %arg14
ret void
}