diff options
| -rw-r--r-- | llvm/test/Transforms/InstCombine/logical-select.ll | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/llvm/test/Transforms/InstCombine/logical-select.ll b/llvm/test/Transforms/InstCombine/logical-select.ll index 2d77dd220ef..db8923f5b73 100644 --- a/llvm/test/Transforms/InstCombine/logical-select.ll +++ b/llvm/test/Transforms/InstCombine/logical-select.ll @@ -274,6 +274,46 @@ define i1 @bools(i1 %a, i1 %b, i1 %c) { ret i1 %or } +; Form a select if we know we can get replace 2 simple logic ops. + +define i1 @bools_multi_uses1(i1 %a, i1 %b, i1 %c) { +; CHECK-LABEL: @bools_multi_uses1( +; CHECK-NEXT: [[NOT:%.*]] = xor i1 %c, true +; CHECK-NEXT: [[AND1:%.*]] = and i1 [[NOT]], %a +; CHECK-NEXT: [[TMP1:%.*]] = select i1 %c, i1 %b, i1 %a +; CHECK-NEXT: [[XOR:%.*]] = xor i1 [[TMP1]], [[AND1]] +; CHECK-NEXT: ret i1 [[XOR]] +; + %not = xor i1 %c, -1 + %and1 = and i1 %not, %a + %and2 = and i1 %c, %b + %or = or i1 %and1, %and2 + %xor = xor i1 %or, %and1 + ret i1 %xor +} + +; FIXME: Don't replace a cheap logic op with a potentially expensive select +; unless we can also eliminate one of the other original ops. + +define i1 @bools_multi_uses2(i1 %a, i1 %b, i1 %c) { +; CHECK-LABEL: @bools_multi_uses2( +; CHECK-NEXT: [[NOT:%.*]] = xor i1 %c, true +; CHECK-NEXT: [[AND1:%.*]] = and i1 [[NOT]], %a +; CHECK-NEXT: [[AND2:%.*]] = and i1 %c, %b +; CHECK-NEXT: [[TMP1:%.*]] = select i1 %c, i1 %b, i1 %a +; CHECK-NEXT: [[ADD:%.*]] = xor i1 [[AND1]], [[AND2]] +; CHECK-NEXT: [[XOR:%.*]] = xor i1 [[TMP1]], [[ADD]] +; CHECK-NEXT: ret i1 [[XOR]] +; + %not = xor i1 %c, -1 + %and1 = and i1 %not, %a + %and2 = and i1 %c, %b + %or = or i1 %and1, %and2 + %add = add i1 %and1, %and2 + %xor = xor i1 %or, %add + ret i1 %xor +} + define <4 x i1> @vec_of_bools(<4 x i1> %a, <4 x i1> %b, <4 x i1> %c) { ; CHECK-LABEL: @vec_of_bools( ; CHECK-NEXT: [[TMP1:%.*]] = select <4 x i1> %c, <4 x i1> %b, <4 x i1> %a |
