diff options
| -rw-r--r-- | llvm/lib/Analysis/InstructionSimplify.cpp | 20 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstSimplify/result-of-usub-by-nonzero-is-non-zero-and-no-overflow.ll | 16 |
2 files changed, 24 insertions, 12 deletions
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp index 5e3a22aba96..defa3c3ea56 100644 --- a/llvm/lib/Analysis/InstructionSimplify.cpp +++ b/llvm/lib/Analysis/InstructionSimplify.cpp @@ -1381,6 +1381,26 @@ static Value *simplifyUnsignedRangeCheck(ICmpInst *ZeroICmp, return nullptr; ICmpInst::Predicate UnsignedPred; + + // Y = (A - B); Y >= A && Y != 0 --> Y >= A iff B != 0 + // Y = (A - B); Y < A || Y == 0 --> Y < A iff B != 0 + Value *A, *B; + if (match(Y, m_Sub(m_Value(A), m_Value(B))) && + match(UnsignedICmp, + m_c_ICmp(UnsignedPred, m_Specific(Y), m_Specific(A)))) { + if (UnsignedICmp->getOperand(0) != Y) + UnsignedPred = ICmpInst::getSwappedPredicate(UnsignedPred); + + if (UnsignedPred == ICmpInst::ICMP_UGE && IsAnd && + EqPred == ICmpInst::ICMP_NE && + isKnownNonZero(B, Q.DL, /*Depth=*/0, Q.AC, Q.CxtI, Q.DT)) + return UnsignedICmp; + if (UnsignedPred == ICmpInst::ICMP_ULT && !IsAnd && + EqPred == ICmpInst::ICMP_EQ && + isKnownNonZero(B, Q.DL, /*Depth=*/0, Q.AC, Q.CxtI, Q.DT)) + return UnsignedICmp; + } + if (match(UnsignedICmp, m_ICmp(UnsignedPred, m_Value(X), m_Specific(Y))) && ICmpInst::isUnsigned(UnsignedPred)) ; diff --git a/llvm/test/Transforms/InstSimplify/result-of-usub-by-nonzero-is-non-zero-and-no-overflow.ll b/llvm/test/Transforms/InstSimplify/result-of-usub-by-nonzero-is-non-zero-and-no-overflow.ll index 38538ff3736..f52f5e55dd0 100644 --- a/llvm/test/Transforms/InstSimplify/result-of-usub-by-nonzero-is-non-zero-and-no-overflow.ll +++ b/llvm/test/Transforms/InstSimplify/result-of-usub-by-nonzero-is-non-zero-and-no-overflow.ll @@ -10,9 +10,7 @@ define i1 @t0(i64 %base, i64* nonnull %offsetptr) { ; CHECK-NEXT: [[OFFSET:%.*]] = ptrtoint i64* [[OFFSETPTR:%.*]] to i64 ; CHECK-NEXT: [[ADJUSTED:%.*]] = sub i64 [[BASE:%.*]], [[OFFSET]] ; CHECK-NEXT: [[NO_UNDERFLOW:%.*]] = icmp uge i64 [[ADJUSTED]], [[BASE]] -; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i64 [[ADJUSTED]], 0 -; CHECK-NEXT: [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: ret i1 [[NO_UNDERFLOW]] ; %offset = ptrtoint i64* %offsetptr to i64 @@ -28,9 +26,7 @@ define i1 @t1(i64 %base, i64* nonnull %offsetptr) { ; CHECK-NEXT: [[OFFSET:%.*]] = ptrtoint i64* [[OFFSETPTR:%.*]] to i64 ; CHECK-NEXT: [[ADJUSTED:%.*]] = sub i64 [[BASE:%.*]], [[OFFSET]] ; CHECK-NEXT: [[NO_UNDERFLOW:%.*]] = icmp ult i64 [[ADJUSTED]], [[BASE]] -; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp eq i64 [[ADJUSTED]], 0 -; CHECK-NEXT: [[R:%.*]] = or i1 [[NOT_NULL]], [[NO_UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: ret i1 [[NO_UNDERFLOW]] ; %offset = ptrtoint i64* %offsetptr to i64 @@ -46,9 +42,7 @@ define i1 @t2_commutative(i64 %base, i64* nonnull %offsetptr) { ; CHECK-NEXT: [[OFFSET:%.*]] = ptrtoint i64* [[OFFSETPTR:%.*]] to i64 ; CHECK-NEXT: [[ADJUSTED:%.*]] = sub i64 [[BASE:%.*]], [[OFFSET]] ; CHECK-NEXT: [[NO_UNDERFLOW:%.*]] = icmp ule i64 [[BASE]], [[ADJUSTED]] -; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i64 [[ADJUSTED]], 0 -; CHECK-NEXT: [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: ret i1 [[NO_UNDERFLOW]] ; %offset = ptrtoint i64* %offsetptr to i64 @@ -64,9 +58,7 @@ define i1 @t3_commutative(i64 %base, i64* nonnull %offsetptr) { ; CHECK-NEXT: [[OFFSET:%.*]] = ptrtoint i64* [[OFFSETPTR:%.*]] to i64 ; CHECK-NEXT: [[ADJUSTED:%.*]] = sub i64 [[BASE:%.*]], [[OFFSET]] ; CHECK-NEXT: [[NO_UNDERFLOW:%.*]] = icmp ugt i64 [[BASE]], [[ADJUSTED]] -; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp eq i64 [[ADJUSTED]], 0 -; CHECK-NEXT: [[R:%.*]] = or i1 [[NOT_NULL]], [[NO_UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: ret i1 [[NO_UNDERFLOW]] ; %offset = ptrtoint i64* %offsetptr to i64 |
