llvm-project/llvm/test/Transforms/InstCombine/dont-distribute-phi.ll

34 lines
852 B
LLVM

; RUN: opt < %s -instcombine -S | FileCheck %s
;
; This test ensures that InstCombine does not distribute And over Xor
; using simplifications involving undef.
define zeroext i1 @foo(i32 %arg) {
; CHECK-LABEL: @foo(
entry:
%cmp1 = icmp eq i32 %arg, 37
br i1 %cmp1, label %bb_then, label %bb_else
bb_then:
call void @bar()
br label %bb_exit
bb_else:
%cmp2 = icmp slt i32 %arg, 17
br label %bb_exit
; CHECK: bb_exit:
; CHECK-NEXT: [[PHI1:%.*]] = phi i1 [ [[CMP2:%.*]], [[BB_ELSE:%.*]] ], [ undef, [[BB_THEN:%.*]] ]
; CHECK-NEXT: [[XOR1:%.*]] = xor i1 [[CMP1:%.*]], true
; CHECK-NEXT: [[AND1:%.*]] = and i1 [[PHI1]], [[XOR1]]
; CHECK-NEXT: ret i1 [[AND1]]
bb_exit:
%phi1 = phi i1 [ %cmp2, %bb_else ], [ undef, %bb_then ]
%xor1 = xor i1 %cmp1, true
%and1 = and i1 %phi1, %xor1
ret i1 %and1
}
declare void @bar()