llvm/test/CodeGen/X86/2010-11-18-SelectOfExtload.ll
Duncan Sands dcfd3a798f The DAGCombiner was threading select over pairs of extending loads even
if the extension types were not the same.  The result was that if you
fed a select with sext and zext loads, as in the testcase, then it
would get turned into a zext (or sext) of the select, which is wrong
in the cases when it should have been an sext (resp. zext).  Reported
and diagnosed by Sebastien Deldon.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119728 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-18 20:05:18 +00:00

16 lines
386 B
LLVM

; RUN: llc < %s -march=x86 | FileCheck %s
; Both values were being zero extended.
@u = external global i8
@s = external global i8
define i32 @foo(i1 %cond) {
; CHECK: @foo
%u_base = load i8* @u
%u_val = zext i8 %u_base to i32
; CHECK: movzbl
; CHECK: movsbl
%s_base = load i8* @s
%s_val = sext i8 %s_base to i32
%val = select i1 %cond, i32 %u_val, i32 %s_val
ret i32 %val
}