llvm/test/Transforms/InstCombine/phi-select-constexpr.ll
Duncan P. N. Exon Smith 42883d0ac4 Don't use isNullValue to evaluate ConstantExpr
ConstantExpr can evaluate to false even when isNullValue gives false.

Fixes PR18143.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196611 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-06 21:48:36 +00:00

20 lines
490 B
LLVM

; RUN: opt < %s -S -instcombine | FileCheck %s
@A = extern_weak global i32, align 4
@B = extern_weak global i32, align 4
define i32 @foo(i1 %which) {
entry:
br i1 %which, label %final, label %delay
delay:
br label %final
; CHECK-LABEL: final:
; CHECK: phi i32 [ 1, %entry ], [ select (i1 icmp eq (i32* @A, i32* @B), i32 2, i32 1), %delay ]
final:
%use2 = phi i1 [ false, %entry ], [ icmp eq (i32* @A, i32* @B), %delay ]
%value = select i1 %use2, i32 2, i32 1
ret i32 %value
}