54 lines
1.5 KiB
LLVM
54 lines
1.5 KiB
LLVM
; 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
|
|
}
|