diff options
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | 27 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/result-of-add-of-negative-is-non-zero-and-no-underflow.ll | 61 |
2 files changed, 50 insertions, 38 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index 7eb1e980fb7..3eeb2272613 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -1061,6 +1061,10 @@ static Value *foldUnsignedUnderflowCheck(ICmpInst *ZeroICmp, !ICmpInst::isEquality(EqPred)) return nullptr; + auto IsKnownNonZero = [&](Value *V) { + return isKnownNonZero(V, Q.DL, /*Depth=*/0, Q.AC, Q.CxtI, Q.DT); + }; + ICmpInst::Predicate UnsignedPred; Value *A, *B; @@ -1071,15 +1075,32 @@ static Value *foldUnsignedUnderflowCheck(ICmpInst *ZeroICmp, if (UnsignedICmp->getOperand(0) != ZeroCmpOp) UnsignedPred = ICmpInst::getSwappedPredicate(UnsignedPred); + auto GetKnownNonZeroAndOther = [&](Value *&NonZero, Value *&Other) { + if (!IsKnownNonZero(NonZero)) + std::swap(NonZero, Other); + return IsKnownNonZero(NonZero); + }; + // Given ZeroCmpOp = (A + B) // ZeroCmpOp <= A && ZeroCmpOp != 0 --> (0-B) < A // ZeroCmpOp > A || ZeroCmpOp == 0 --> (0-B) >= A + // + // ZeroCmpOp < A && ZeroCmpOp != 0 --> (0-X) < Y iff + // ZeroCmpOp >= A || ZeroCmpOp == 0 --> (0-X) >= Y iff + // with X being the value (A/B) that is known to be non-zero, + // and Y being remaining value. if (UnsignedPred == ICmpInst::ICMP_ULE && EqPred == ICmpInst::ICMP_NE && IsAnd) return Builder.CreateICmpULT(Builder.CreateNeg(B), A); + if (UnsignedPred == ICmpInst::ICMP_ULT && EqPred == ICmpInst::ICMP_NE && + IsAnd && GetKnownNonZeroAndOther(B, A)) + return Builder.CreateICmpULT(Builder.CreateNeg(B), A); if (UnsignedPred == ICmpInst::ICMP_UGT && EqPred == ICmpInst::ICMP_EQ && !IsAnd) return Builder.CreateICmpUGE(Builder.CreateNeg(B), A); + if (UnsignedPred == ICmpInst::ICMP_UGE && EqPred == ICmpInst::ICMP_EQ && + !IsAnd && GetKnownNonZeroAndOther(B, A)) + return Builder.CreateICmpUGE(Builder.CreateNeg(B), A); } Value *Base, *Offset; @@ -1094,12 +1115,10 @@ static Value *foldUnsignedUnderflowCheck(ICmpInst *ZeroICmp, UnsignedPred = ICmpInst::getSwappedPredicate(UnsignedPred); if (UnsignedPred == ICmpInst::ICMP_ULT && IsAnd && - EqPred == ICmpInst::ICMP_NE && - isKnownNonZero(Offset, Q.DL, /*Depth=*/0, Q.AC, Q.CxtI, Q.DT)) + EqPred == ICmpInst::ICMP_NE && IsKnownNonZero(Offset)) return Builder.CreateICmpUGT(Base, Offset); if (UnsignedPred == ICmpInst::ICMP_UGE && !IsAnd && - EqPred == ICmpInst::ICMP_EQ && - isKnownNonZero(Offset, Q.DL, /*Depth=*/0, Q.AC, Q.CxtI, Q.DT)) + EqPred == ICmpInst::ICMP_EQ && IsKnownNonZero(Offset)) return Builder.CreateICmpULE(Base, Offset); } diff --git a/llvm/test/Transforms/InstCombine/result-of-add-of-negative-is-non-zero-and-no-underflow.ll b/llvm/test/Transforms/InstCombine/result-of-add-of-negative-is-non-zero-and-no-underflow.ll index 00a37a5822d..5b48b5e30ff 100644 --- a/llvm/test/Transforms/InstCombine/result-of-add-of-negative-is-non-zero-and-no-underflow.ll +++ b/llvm/test/Transforms/InstCombine/result-of-add-of-negative-is-non-zero-and-no-underflow.ll @@ -31,10 +31,9 @@ define i1 @t1(i8 %base, i8 %offset) { ; CHECK-NEXT: call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[ADJUSTED:%.*]] = add i8 [[BASE]], [[OFFSET:%.*]] ; CHECK-NEXT: call void @use8(i8 [[ADJUSTED]]) -; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0 -; CHECK-NEXT: [[NO_UNDERFLOW:%.*]] = icmp ult i8 [[ADJUSTED]], [[BASE]] -; CHECK-NEXT: [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = sub i8 0, [[BASE]] +; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i8 [[TMP1]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP2]] ; %cmp = icmp slt i8 %base, 0 call void @llvm.assume(i1 %cmp) @@ -54,10 +53,9 @@ define i1 @t2(i8 %base, i8 %offset) { ; CHECK-NEXT: call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[ADJUSTED:%.*]] = add i8 [[BASE:%.*]], [[OFFSET]] ; CHECK-NEXT: call void @use8(i8 [[ADJUSTED]]) -; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0 -; CHECK-NEXT: [[NO_UNDERFLOW:%.*]] = icmp ult i8 [[ADJUSTED]], [[BASE]] -; CHECK-NEXT: [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = sub i8 0, [[OFFSET]] +; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i8 [[TMP1]], [[BASE]] +; CHECK-NEXT: ret i1 [[TMP2]] ; %cmp = icmp slt i8 %offset, 0 call void @llvm.assume(i1 %cmp) @@ -79,9 +77,9 @@ define i1 @t3_oneuse0(i8 %base, i8 %offset) { ; CHECK-NEXT: call void @use8(i8 [[ADJUSTED]]) ; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0 ; CHECK-NEXT: call void @use1(i1 [[NOT_NULL]]) -; CHECK-NEXT: [[NO_UNDERFLOW:%.*]] = icmp ult i8 [[ADJUSTED]], [[BASE]] -; CHECK-NEXT: [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = sub i8 0, [[BASE]] +; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i8 [[TMP1]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP2]] ; %cmp = icmp slt i8 %base, 0 call void @llvm.assume(i1 %cmp) @@ -100,11 +98,11 @@ define i1 @t4_oneuse1(i8 %base, i8 %offset) { ; CHECK-NEXT: call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[ADJUSTED:%.*]] = add i8 [[BASE]], [[OFFSET:%.*]] ; CHECK-NEXT: call void @use8(i8 [[ADJUSTED]]) -; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0 ; CHECK-NEXT: [[NO_UNDERFLOW:%.*]] = icmp ult i8 [[ADJUSTED]], [[BASE]] ; CHECK-NEXT: call void @use1(i1 [[NO_UNDERFLOW]]) -; CHECK-NEXT: [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = sub i8 0, [[BASE]] +; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i8 [[TMP1]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP2]] ; %cmp = icmp slt i8 %base, 0 call void @llvm.assume(i1 %cmp) @@ -149,10 +147,9 @@ define i1 @t6_commutativity0(i8 %base, i8 %offset) { ; CHECK-NEXT: call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[ADJUSTED:%.*]] = add i8 [[BASE]], [[OFFSET:%.*]] ; CHECK-NEXT: call void @use8(i8 [[ADJUSTED]]) -; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0 -; CHECK-NEXT: [[NO_UNDERFLOW:%.*]] = icmp ult i8 [[ADJUSTED]], [[BASE]] -; CHECK-NEXT: [[R:%.*]] = and i1 [[NO_UNDERFLOW]], [[NOT_NULL]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = sub i8 0, [[BASE]] +; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i8 [[TMP1]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP2]] ; %cmp = icmp slt i8 %base, 0 call void @llvm.assume(i1 %cmp) @@ -170,10 +167,9 @@ define i1 @t7_commutativity1(i8 %base, i8 %offset) { ; CHECK-NEXT: call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[ADJUSTED:%.*]] = add i8 [[BASE]], [[OFFSET:%.*]] ; CHECK-NEXT: call void @use8(i8 [[ADJUSTED]]) -; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0 -; CHECK-NEXT: [[NO_UNDERFLOW:%.*]] = icmp ult i8 [[ADJUSTED]], [[BASE]] -; CHECK-NEXT: [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = sub i8 0, [[BASE]] +; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i8 [[TMP1]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP2]] ; %cmp = icmp slt i8 %base, 0 call void @llvm.assume(i1 %cmp) @@ -191,10 +187,9 @@ define i1 @t7_commutativity3(i8 %base, i8 %offset) { ; CHECK-NEXT: call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[ADJUSTED:%.*]] = add i8 [[BASE]], [[OFFSET:%.*]] ; CHECK-NEXT: call void @use8(i8 [[ADJUSTED]]) -; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0 -; CHECK-NEXT: [[NO_UNDERFLOW:%.*]] = icmp ult i8 [[ADJUSTED]], [[BASE]] -; CHECK-NEXT: [[R:%.*]] = and i1 [[NO_UNDERFLOW]], [[NOT_NULL]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = sub i8 0, [[BASE]] +; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i8 [[TMP1]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP2]] ; %cmp = icmp slt i8 %base, 0 call void @llvm.assume(i1 %cmp) @@ -214,10 +209,9 @@ define i1 @t8(i8 %base, i8 %offset) { ; CHECK-NEXT: call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[ADJUSTED:%.*]] = add i8 [[BASE]], [[OFFSET:%.*]] ; CHECK-NEXT: call void @use8(i8 [[ADJUSTED]]) -; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp eq i8 [[ADJUSTED]], 0 -; CHECK-NEXT: [[NO_UNDERFLOW:%.*]] = icmp uge i8 [[ADJUSTED]], [[BASE]] -; CHECK-NEXT: [[R:%.*]] = or i1 [[NOT_NULL]], [[NO_UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = sub i8 0, [[BASE]] +; CHECK-NEXT: [[TMP2:%.*]] = icmp uge i8 [[TMP1]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP2]] ; %cmp = icmp slt i8 %base, 0 call void @llvm.assume(i1 %cmp) @@ -237,10 +231,9 @@ define i1 @t9(i8 %base, i8 %offset) { ; CHECK-NEXT: call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[ADJUSTED:%.*]] = add i8 [[BASE]], [[OFFSET:%.*]] ; CHECK-NEXT: call void @use8(i8 [[ADJUSTED]]) -; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0 -; CHECK-NEXT: [[NO_UNDERFLOW:%.*]] = icmp ult i8 [[ADJUSTED]], [[OFFSET]] -; CHECK-NEXT: [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = sub i8 0, [[BASE]] +; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i8 [[TMP1]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP2]] ; %cmp = icmp slt i8 %base, 0 call void @llvm.assume(i1 %cmp) |
