Index: llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp =================================================================== --- llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -1084,6 +1084,27 @@ return Builder.CreateICmpULE(Base, Offset); } + if (!match(UnsignedICmp, + m_c_ICmp(UnsignedPred, m_Specific(Base), m_Specific(Offset))) || + !ICmpInst::isUnsigned(UnsignedPred)) + return nullptr; + if (UnsignedICmp->getOperand(0) != Base) + UnsignedPred = ICmpInst::getSwappedPredicate(UnsignedPred); + + // Base >=/> Offset && (Base - Offset) != 0 <--> Base > Offset + // (no overflow and not null) + if ((UnsignedPred == ICmpInst::ICMP_UGE || + UnsignedPred == ICmpInst::ICMP_UGT) && + EqPred == ICmpInst::ICMP_NE && IsAnd) + return Builder.CreateICmpUGT(Base, Offset); + + // Base <=/< Offset || (Base - Offset) == 0 <--> Base <= Offset + // (overflow or null) + if ((UnsignedPred == ICmpInst::ICMP_ULE || + UnsignedPred == ICmpInst::ICMP_ULT) && + EqPred == ICmpInst::ICMP_EQ && !IsAnd) + return Builder.CreateICmpULE(Base, Offset); + return nullptr; } Index: llvm/trunk/test/Transforms/InstCombine/result-of-usub-is-non-zero-and-no-overflow.ll =================================================================== --- llvm/trunk/test/Transforms/InstCombine/result-of-usub-is-non-zero-and-no-overflow.ll +++ llvm/trunk/test/Transforms/InstCombine/result-of-usub-is-non-zero-and-no-overflow.ll @@ -24,8 +24,8 @@ ; CHECK-NEXT: call void @use1(i1 [[NO_UNDERFLOW]]) ; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0 ; CHECK-NEXT: call void @use1(i1 [[NOT_NULL]]) -; CHECK-NEXT: [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i8 [[BASE]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP1]] ; %adjusted = sub i8 %base, %offset call void @use8(i8 %adjusted) @@ -45,8 +45,8 @@ ; CHECK-NEXT: call void @use1(i1 [[NO_UNDERFLOW]]) ; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0 ; CHECK-NEXT: call void @use1(i1 [[NOT_NULL]]) -; CHECK-NEXT: [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i8 [[BASE]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP1]] ; %adjusted = sub i8 %base, %offset call void @use8(i8 %adjusted) @@ -65,8 +65,8 @@ ; CHECK-NEXT: call void @use1(i1 [[NO_UNDERFLOW]]) ; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0 ; CHECK-NEXT: call void @use1(i1 [[NOT_NULL]]) -; CHECK-NEXT: [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i8 [[BASE]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP1]] ; %adjusted = sub i8 %base, %offset call void @use8(i8 %adjusted) @@ -115,8 +115,8 @@ ; CHECK-NEXT: call void @use1(i1 [[NO_UNDERFLOW]]) ; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0 ; CHECK-NEXT: call void @use1(i1 [[NOT_NULL]]) -; CHECK-NEXT: [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i8 [[BASE]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP1]] ; %adjusted = sub i8 %base, %offset call void @use8(i8 %adjusted) @@ -135,8 +135,8 @@ ; CHECK-NEXT: call void @use1(i1 [[NO_UNDERFLOW]]) ; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0 ; CHECK-NEXT: call void @use1(i1 [[NOT_NULL]]) -; CHECK-NEXT: [[R:%.*]] = and i1 [[NO_UNDERFLOW]], [[NOT_NULL]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i8 [[BASE]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP1]] ; %adjusted = sub i8 %base, %offset call void @use8(i8 %adjusted) @@ -155,8 +155,8 @@ ; CHECK-NEXT: call void @use1(i1 [[NO_UNDERFLOW]]) ; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0 ; CHECK-NEXT: call void @use1(i1 [[NOT_NULL]]) -; CHECK-NEXT: [[R:%.*]] = and i1 [[NO_UNDERFLOW]], [[NOT_NULL]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i8 [[BASE]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP1]] ; %adjusted = sub i8 %base, %offset call void @use8(i8 %adjusted) @@ -206,8 +206,8 @@ ; CHECK-NEXT: call void @use1(i1 [[UNDERFLOW]]) ; CHECK-NEXT: [[NULL:%.*]] = icmp eq i8 [[ADJUSTED]], 0 ; CHECK-NEXT: call void @use1(i1 [[NULL]]) -; CHECK-NEXT: [[R:%.*]] = or i1 [[NULL]], [[UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ule i8 [[BASE]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP1]] ; %adjusted = sub i8 %base, %offset call void @use8(i8 %adjusted) @@ -226,8 +226,8 @@ ; CHECK-NEXT: call void @use1(i1 [[UNDERFLOW]]) ; CHECK-NEXT: [[NULL:%.*]] = icmp eq i8 [[ADJUSTED]], 0 ; CHECK-NEXT: call void @use1(i1 [[NULL]]) -; CHECK-NEXT: [[R:%.*]] = or i1 [[NULL]], [[UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ule i8 [[BASE]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP1]] ; %adjusted = sub i8 %base, %offset call void @use8(i8 %adjusted) @@ -272,8 +272,8 @@ ; CHECK-NEXT: call void @use1(i1 [[UNDERFLOW]]) ; CHECK-NEXT: [[NULL:%.*]] = icmp eq i8 [[ADJUSTED]], 0 ; CHECK-NEXT: call void @use1(i1 [[NULL]]) -; CHECK-NEXT: [[R:%.*]] = or i1 [[NULL]], [[UNDERFLOW]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ule i8 [[BASE]], [[OFFSET]] +; CHECK-NEXT: ret i1 [[TMP1]] ; %adjusted = sub i8 %base, %offset call void @use8(i8 %adjusted)