diff options
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | 23 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/result-of-add-of-negative-or-zero-is-non-zero-and-no-underflow.ll | 47 |
2 files changed, 42 insertions, 28 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index cde4cc1e842..7eb1e980fb7 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -1061,12 +1061,31 @@ static Value *foldUnsignedUnderflowCheck(ICmpInst *ZeroICmp, !ICmpInst::isEquality(EqPred)) return nullptr; + ICmpInst::Predicate UnsignedPred; + + Value *A, *B; + if (match(UnsignedICmp, + m_c_ICmp(UnsignedPred, m_Specific(ZeroCmpOp), m_Value(A))) && + match(ZeroCmpOp, m_c_Add(m_Specific(A), m_Value(B))) && + (ZeroICmp->hasOneUse() || UnsignedICmp->hasOneUse())) { + if (UnsignedICmp->getOperand(0) != ZeroCmpOp) + UnsignedPred = ICmpInst::getSwappedPredicate(UnsignedPred); + + // Given ZeroCmpOp = (A + B) + // ZeroCmpOp <= A && ZeroCmpOp != 0 --> (0-B) < A + // ZeroCmpOp > A || ZeroCmpOp == 0 --> (0-B) >= A + if (UnsignedPred == ICmpInst::ICMP_ULE && EqPred == ICmpInst::ICMP_NE && + IsAnd) + return Builder.CreateICmpULT(Builder.CreateNeg(B), A); + if (UnsignedPred == ICmpInst::ICMP_UGT && EqPred == ICmpInst::ICMP_EQ && + !IsAnd) + return Builder.CreateICmpUGE(Builder.CreateNeg(B), A); + } + Value *Base, *Offset; if (!match(ZeroCmpOp, m_Sub(m_Value(Base), m_Value(Offset)))) return nullptr; - ICmpInst::Predicate UnsignedPred; - // ZeroCmpOp < Base && ZeroCmpOp != 0 --> Base > Offset iff Offset != 0 // ZeroCmpOp >= Base || ZeroCmpOp == 0 --> Base <= Base iff Offset != 0 if (match(UnsignedICmp, diff --git a/llvm/test/Transforms/InstCombine/result-of-add-of-negative-or-zero-is-non-zero-and-no-underflow.ll b/llvm/test/Transforms/InstCombine/result-of-add-of-negative-or-zero-is-non-zero-and-no-underflow.ll index de4fd42b5bf..b8a29e4fab2 100644 --- a/llvm/test/Transforms/InstCombine/result-of-add-of-negative-or-zero-is-non-zero-and-no-underflow.ll +++ b/llvm/test/Transforms/InstCombine/result-of-add-of-negative-or-zero-is-non-zero-and-no-underflow.ll @@ -10,10 +10,9 @@ define i1 @t0(i8 %base, i8 %offset) { ; CHECK-LABEL: @t0( ; 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 ule 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]] ; %adjusted = add i8 %base, %offset call void @use8(i8 %adjusted) @@ -30,9 +29,9 @@ define i1 @t1_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 ule 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]] ; %adjusted = add i8 %base, %offset call void @use8(i8 %adjusted) @@ -46,11 +45,11 @@ define i1 @t2_oneuse1(i8 %base, i8 %offset) { ; CHECK-LABEL: @t2_oneuse1( ; 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 ule 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, [[OFFSET]] +; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i8 [[TMP1]], [[BASE]] +; CHECK-NEXT: ret i1 [[TMP2]] ; %adjusted = add i8 %base, %offset call void @use8(i8 %adjusted) @@ -85,10 +84,9 @@ define i1 @t4_commutativity0(i8 %base, i8 %offset) { ; CHECK-LABEL: @t4_commutativity0( ; 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 ule i8 [[ADJUSTED]], [[BASE]] -; CHECK-NEXT: [[R:%.*]] = and i1 [[NO_UNDERFLOW]], [[NOT_NULL]] -; 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]] ; %adjusted = add i8 %base, %offset call void @use8(i8 %adjusted) @@ -101,10 +99,9 @@ define i1 @t5_commutativity1(i8 %base, i8 %offset) { ; CHECK-LABEL: @t5_commutativity1( ; 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 ule 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]] ; %adjusted = add i8 %base, %offset call void @use8(i8 %adjusted) @@ -117,10 +114,9 @@ define i1 @t6_commutativity3(i8 %base, i8 %offset) { ; CHECK-LABEL: @t6_commutativity3( ; 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 ule i8 [[ADJUSTED]], [[BASE]] -; CHECK-NEXT: [[R:%.*]] = and i1 [[NO_UNDERFLOW]], [[NOT_NULL]] -; 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]] ; %adjusted = add i8 %base, %offset call void @use8(i8 %adjusted) @@ -152,10 +148,9 @@ define i1 @t8(i8 %base, i8 %offset) { ; CHECK-LABEL: @t8( ; 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 ule 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]] ; %adjusted = add i8 %base, %offset call void @use8(i8 %adjusted) |
