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authorSanjay Patel <spatel@rotateright.com>2020-08-03 08:58:41 -0400
committerSanjay Patel <spatel@rotateright.com>2020-08-03 08:58:41 -0400
commitf19a9be385ef782140d1e551e03553daa79d1bc1 (patch)
tree5469e230f4b46600cca62b6a210b179273dc64c8
parentfd63e46941fc48d4cc777ef94e185637898d0adb (diff)
downloadllvm-f19a9be385ef782140d1e551e03553daa79d1bc1.tar.gz
Revert "[InstCombine] reduce xor-of-or's bitwise logic (PR46955)"
This reverts commit 2265d01f2a5bd153959701e22f5be2a40e1674a3. Seeing bot failures after this change like: http://lab.llvm.org:8011/builders/clang-cmake-x86_64-sde-avx512-linux/builds/42586
-rw-r--r--llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp14
-rw-r--r--llvm/test/Transforms/InstCombine/xor.ll24
2 files changed, 12 insertions, 26 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index ef1e8dbe0155..030d2f203ed6 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -3351,20 +3351,6 @@ Instruction *InstCombinerImpl::visitXor(BinaryOperator &I) {
match(Op1, m_Not(m_Specific(A))))
return BinaryOperator::CreateNot(Builder.CreateAnd(A, B));
- // (A | B) ^ (A | C) --> (B ^ C) & ~A -- There are 4 commuted variants.
- // TODO: Loosen one-use restriction if common operand is a constant.
- Value *D;
- if (match(Op0, m_OneUse(m_Or(m_Value(A), m_Value(B)))) &&
- match(Op1, m_OneUse(m_Or(m_Value(C), m_Value(D))))) {
- if (B == C || B == D)
- std::swap(A, B);
- if (A == C)
- std::swap(C, D);
- if (A == D)
- return BinaryOperator::CreateAnd(Builder.CreateXor(B, C),
- Builder.CreateNot(A));
- }
-
if (auto *LHS = dyn_cast<ICmpInst>(I.getOperand(0)))
if (auto *RHS = dyn_cast<ICmpInst>(I.getOperand(1)))
if (Value *V = foldXorOfICmps(LHS, RHS, I))
diff --git a/llvm/test/Transforms/InstCombine/xor.ll b/llvm/test/Transforms/InstCombine/xor.ll
index 2bdb837bff04..a133f2a0e009 100644
--- a/llvm/test/Transforms/InstCombine/xor.ll
+++ b/llvm/test/Transforms/InstCombine/xor.ll
@@ -915,9 +915,9 @@ define <2 x i32> @test51vec(<2 x i32> %x, <2 x i32> %y) {
define i4 @or_or_xor(i4 %x, i4 %y, i4 %z) {
; CHECK-LABEL: @or_or_xor(
-; CHECK-NEXT: [[TMP1:%.*]] = xor i4 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT: [[TMP2:%.*]] = xor i4 [[Z:%.*]], -1
-; CHECK-NEXT: [[R:%.*]] = and i4 [[TMP1]], [[TMP2]]
+; CHECK-NEXT: [[O1:%.*]] = or i4 [[Z:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[O2:%.*]] = or i4 [[Z]], [[Y:%.*]]
+; CHECK-NEXT: [[R:%.*]] = xor i4 [[O1]], [[O2]]
; CHECK-NEXT: ret i4 [[R]]
;
%o1 = or i4 %z, %x
@@ -928,9 +928,9 @@ define i4 @or_or_xor(i4 %x, i4 %y, i4 %z) {
define i4 @or_or_xor_commute1(i4 %x, i4 %y, i4 %z) {
; CHECK-LABEL: @or_or_xor_commute1(
-; CHECK-NEXT: [[TMP1:%.*]] = xor i4 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT: [[TMP2:%.*]] = xor i4 [[Z:%.*]], -1
-; CHECK-NEXT: [[R:%.*]] = and i4 [[TMP1]], [[TMP2]]
+; CHECK-NEXT: [[O1:%.*]] = or i4 [[X:%.*]], [[Z:%.*]]
+; CHECK-NEXT: [[O2:%.*]] = or i4 [[Z]], [[Y:%.*]]
+; CHECK-NEXT: [[R:%.*]] = xor i4 [[O1]], [[O2]]
; CHECK-NEXT: ret i4 [[R]]
;
%o1 = or i4 %x, %z
@@ -941,9 +941,9 @@ define i4 @or_or_xor_commute1(i4 %x, i4 %y, i4 %z) {
define i4 @or_or_xor_commute2(i4 %x, i4 %y, i4 %z) {
; CHECK-LABEL: @or_or_xor_commute2(
-; CHECK-NEXT: [[TMP1:%.*]] = xor i4 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT: [[TMP2:%.*]] = xor i4 [[Z:%.*]], -1
-; CHECK-NEXT: [[R:%.*]] = and i4 [[TMP1]], [[TMP2]]
+; CHECK-NEXT: [[O1:%.*]] = or i4 [[Z:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[O2:%.*]] = or i4 [[Y:%.*]], [[Z]]
+; CHECK-NEXT: [[R:%.*]] = xor i4 [[O1]], [[O2]]
; CHECK-NEXT: ret i4 [[R]]
;
%o1 = or i4 %z, %x
@@ -954,9 +954,9 @@ define i4 @or_or_xor_commute2(i4 %x, i4 %y, i4 %z) {
define <2 x i4> @or_or_xor_commute3(<2 x i4> %x, <2 x i4> %y, <2 x i4> %z) {
; CHECK-LABEL: @or_or_xor_commute3(
-; CHECK-NEXT: [[TMP1:%.*]] = xor <2 x i4> [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT: [[TMP2:%.*]] = xor <2 x i4> [[Z:%.*]], <i4 -1, i4 -1>
-; CHECK-NEXT: [[R:%.*]] = and <2 x i4> [[TMP1]], [[TMP2]]
+; CHECK-NEXT: [[O1:%.*]] = or <2 x i4> [[X:%.*]], [[Z:%.*]]
+; CHECK-NEXT: [[O2:%.*]] = or <2 x i4> [[Y:%.*]], [[Z]]
+; CHECK-NEXT: [[R:%.*]] = xor <2 x i4> [[O1]], [[O2]]
; CHECK-NEXT: ret <2 x i4> [[R]]
;
%o1 = or <2 x i4> %x, %z