llvm-6502/test/CodeGen/X86/test-shrink-bug.ll
Dan Gohman 11596ed43c Fix the x86 test-shrink optimization so that it doesn't shrink comparisons
when one of the bits being tested would end up being the sign bit in the
narrower type, and a signed comparison is being performed, since this would
change the result of the signed comparison. This fixes PR5132.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83670 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-09 20:35:19 +00:00

24 lines
915 B
LLVM

; RUN: llc < %s | FileCheck %s
; Codegen shouldn't reduce the comparison down to testb $-1, %al
; because that changes the result of the signed test.
; PR5132
; CHECK: testw $255, %ax
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-f80:128:128"
target triple = "i386-apple-darwin10.0"
@g_14 = global i8 -6, align 1 ; <i8*> [#uses=1]
declare i32 @func_16(i8 signext %p_19, i32 %p_20) nounwind
define i32 @func_35(i64 %p_38) nounwind ssp {
entry:
%tmp = load i8* @g_14 ; <i8> [#uses=2]
%conv = zext i8 %tmp to i32 ; <i32> [#uses=1]
%cmp = icmp sle i32 1, %conv ; <i1> [#uses=1]
%conv2 = zext i1 %cmp to i32 ; <i32> [#uses=1]
%call = call i32 @func_16(i8 signext %tmp, i32 %conv2) ssp ; <i32> [#uses=1]
ret i32 1
}