diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index 7d5c71eafed6..f8d23c40e0c9 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -5678,23 +5678,31 @@ ScalarEvolution::getRangeRef(const SCEV *S, ConservativeResult = ConservativeResult.intersectWith( ConstantRange(C->getAPInt(), APInt(BitWidth, 0)), RangeType); - // If there's no signed wrap, and all the operands have the same sign or - // zero, the value won't ever change sign. + // If there's no signed wrap, and all the operands except initial value have + // the same sign or zero, the value won't ever be: + // 1: smaller than initial value if operands are non negative, + // 2: bigger than initial value if operands are non positive. + // For both cases, value can not cross signed min/max boundary. if (AddRec->hasNoSignedWrap()) { bool AllNonNeg = true; bool AllNonPos = true; - for (unsigned i = 0, e = AddRec->getNumOperands(); i != e; ++i) { - if (!isKnownNonNegative(AddRec->getOperand(i))) AllNonNeg = false; - if (!isKnownNonPositive(AddRec->getOperand(i))) AllNonPos = false; + for (unsigned i = 1, e = AddRec->getNumOperands(); i != e; ++i) { + if (!isKnownNonNegative(AddRec->getOperand(i))) + AllNonNeg = false; + if (!isKnownNonPositive(AddRec->getOperand(i))) + AllNonPos = false; } if (AllNonNeg) ConservativeResult = ConservativeResult.intersectWith( - ConstantRange(APInt(BitWidth, 0), - APInt::getSignedMinValue(BitWidth)), RangeType); + ConstantRange::getNonEmpty(getSignedRangeMin(AddRec->getStart()), + APInt::getSignedMinValue(BitWidth)), + RangeType); else if (AllNonPos) ConservativeResult = ConservativeResult.intersectWith( - ConstantRange(APInt::getSignedMinValue(BitWidth), - APInt(BitWidth, 1)), RangeType); + ConstantRange::getNonEmpty( + APInt::getSignedMinValue(BitWidth), + getSignedRangeMax(AddRec->getStart()) + 1), + RangeType); } // TODO: non-affine addrec diff --git a/llvm/test/Analysis/ScalarEvolution/range_nw_flag.ll b/llvm/test/Analysis/ScalarEvolution/range_nw_flag.ll index 336a84472410..ae447dcdfa57 100644 --- a/llvm/test/Analysis/ScalarEvolution/range_nw_flag.ll +++ b/llvm/test/Analysis/ScalarEvolution/range_nw_flag.ll @@ -40,7 +40,7 @@ exit: } ; CHECK-LABEL: @test-addrec-nsw-start-neg-strip-neg -; CHECK: --> {(-1 + (-10 smin %offset)),+,-1}<%loop> U: [-2147483648,1) S: [-2147483648,1) +; CHECK: --> {(-1 + (-10 smin %offset)),+,-1}<%loop> U: [-2147483648,-10) S: [-2147483648,-10) define void @test-addrec-nsw-start-neg-strip-neg(float* %input, i32 %offset, i32 %numIterations) { entry: %cmp = icmp slt i32 %offset, -10 @@ -60,7 +60,7 @@ exit: } ; CHECK-LABEL: @test-addrec-nsw-start-pos-strip-neg -; CHECK: --> {(-1 + (10 smin %offset)),+,-1}<%loop> U: full-set S: full-set +; CHECK: --> {(-1 + (10 smin %offset)),+,-1}<%loop> U: [-2147483648,10) S: [-2147483648,10) define void @test-addrec-nsw-start-pos-strip-neg(float* %input, i32 %offset, i32 %numIterations) { entry: %cmp = icmp slt i32 %offset, 10 @@ -80,7 +80,7 @@ exit: } ; CHECK-LABEL: @test-addrec-nsw-start-pos-strip-pos -; CHECK: --> {(1 + (10 smax %offset)),+,1}<%loop> U: [0,-2147483648) S: [0,-2147483648) +; CHECK: --> {(1 + (10 smax %offset)),+,1}<%loop> U: [11,-2147483648) S: [11,-2147483648) define void @test-addrec-nsw-start-pos-strip-pos(float* %input, i32 %offset, i32 %numIterations) { entry: %cmp = icmp sgt i32 %offset, 10 @@ -100,7 +100,7 @@ exit: } ; CHECK-LABEL: @test-addrec-nsw-start-neg-strip-pos -; CHECK: --> {(1 + (-10 smax %offset)),+,1}<%loop> U: full-set S: full-set +; CHECK: --> {(1 + (-10 smax %offset)),+,1}<%loop> U: [-9,-2147483648) S: [-9,-2147483648) define void @test-addrec-nsw-start-neg-strip-pos(float* %input, i32 %offset, i32 %numIterations) { entry: %cmp = icmp sgt i32 %offset, -10