| ; RUN: llc < %s -O1 -mtriple=i386-apple-darwin | FileCheck %s | |
| ; | |
| ; Interesting test case where %tmp1220 = xor i32 %tmp862, %tmp592 and | |
| ; %tmp1676 = xor i32 %tmp1634, %tmp1530 have zero demanded bits after | |
| ; DAGCombiner optimization pass. These are changed to undef and in turn | |
| ; the successor shl(s) become shl undef, 1. This pattern then matches | |
| ; shl x, 1 -> add x, x. add undef, undef doesn't guarentee the low | |
| ; order bit is zero and is incorrect. | |
| ; | |
| ; See rdar://9453156 and rdar://9487392. | |
| ; | |
| ; CHECK-NOT: shl | |
| define i32 @foo(i8* %a0, i32* %a2) nounwind { | |
| entry: | |
| %tmp0 = alloca i8 | |
| %tmp1 = alloca i32 | |
| store i8 1, i8* %tmp0 | |
| %tmp921.i7845 = load i8* %a0, align 1 | |
| %tmp309 = xor i8 %tmp921.i7845, 104 | |
| %tmp592 = zext i8 %tmp309 to i32 | |
| %tmp862 = xor i32 1293461297, %tmp592 | |
| %tmp1220 = xor i32 %tmp862, %tmp592 | |
| %tmp1506 = shl i32 %tmp1220, 1 | |
| %tmp1530 = sub i32 %tmp592, %tmp1506 | |
| %tmp1557 = sub i32 %tmp1530, 542767629 | |
| %tmp1607 = and i32 %tmp1557, 1 | |
| store i32 %tmp1607, i32* %tmp1 | |
| %tmp1634 = and i32 %tmp1607, 2080309246 | |
| %tmp1676 = xor i32 %tmp1634, %tmp1530 | |
| %tmp1618 = shl i32 %tmp1676, 1 | |
| %tmp1645 = sub i32 %tmp862, %tmp1618 | |
| %tmp1697 = and i32 %tmp1645, 1 | |
| store i32 %tmp1697, i32* %a2 | |
| ret i32 %tmp1607 | |
| } | |
| ; CHECK-NOT: shl | |
| ; shl undef, 0 -> undef | |
| define i32 @foo2_undef() nounwind { | |
| entry: | |
| %tmp2 = shl i32 undef, 0; | |
| ret i32 %tmp2 | |
| } | |
| ; CHECK-NOT: shl | |
| ; shl undef, x -> 0 | |
| define i32 @foo1_undef(i32* %a0) nounwind { | |
| entry: | |
| %tmp1 = load i32* %a0, align 1 | |
| %tmp2 = shl i32 undef, %tmp1; | |
| ret i32 %tmp2 | |
| } |