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[SCEV] Unify getUnsignedRange and getSignedRange
Summary: This removes some duplicated code, and also helps optimization: e.g. in the test case added, `%idx ULT 128` in `@x` is not currently optimized to `true` by `-indvars` but will be, after this change. The only functional change in ths commit is that for add recurrences, ScalarEvolution::getRange will be more aggressive -- computing the unsigned (resp. signed) range for a SCEVAddRecExpr will now look at the NSW (resp. NUW) bits and check for signed (resp. unsigned) overflow. This can be a strict improvement in some cases (such as the attached test case), and should be no worse in other cases. Reviewers: atrick, nlewycky Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D8142 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231709 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Sanjoy Das
parent
afeb9bf44e
commit
cd5029d001
@ -388,31 +388,30 @@ namespace llvm {
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/// computeBlockDisposition - Compute a BlockDisposition value.
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BlockDisposition computeBlockDisposition(const SCEV *S, const BasicBlock *BB);
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/// UnsignedRanges - Memoized results from getUnsignedRange
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/// UnsignedRanges - Memoized results from getRange
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DenseMap<const SCEV *, ConstantRange> UnsignedRanges;
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/// SignedRanges - Memoized results from getSignedRange
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/// SignedRanges - Memoized results from getRange
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DenseMap<const SCEV *, ConstantRange> SignedRanges;
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/// setUnsignedRange - Set the memoized unsigned range for the given SCEV.
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const ConstantRange &setUnsignedRange(const SCEV *S,
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const ConstantRange &CR) {
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/// RangeSignHint - Used to parameterize getRange
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enum RangeSignHint { HINT_RANGE_UNSIGNED, HINT_RANGE_SIGNED };
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/// setRange - Set the memoized range for the given SCEV.
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const ConstantRange &setRange(const SCEV *S, RangeSignHint Hint,
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const ConstantRange &CR) {
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DenseMap<const SCEV *, ConstantRange> &Cache =
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Hint == HINT_RANGE_UNSIGNED ? UnsignedRanges : SignedRanges;
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std::pair<DenseMap<const SCEV *, ConstantRange>::iterator, bool> Pair =
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UnsignedRanges.insert(std::make_pair(S, CR));
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Cache.insert(std::make_pair(S, CR));
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if (!Pair.second)
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Pair.first->second = CR;
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return Pair.first->second;
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}
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/// setUnsignedRange - Set the memoized signed range for the given SCEV.
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const ConstantRange &setSignedRange(const SCEV *S,
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const ConstantRange &CR) {
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std::pair<DenseMap<const SCEV *, ConstantRange>::iterator, bool> Pair =
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SignedRanges.insert(std::make_pair(S, CR));
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if (!Pair.second)
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Pair.first->second = CR;
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return Pair.first->second;
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}
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/// getRange - Determine the range for a particular SCEV.
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ConstantRange getRange(const SCEV *S, RangeSignHint Hint);
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/// createSCEV - We know that there is no SCEV for the specified value.
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/// Analyze the expression.
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@ -843,11 +842,15 @@ namespace llvm {
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/// getUnsignedRange - Determine the unsigned range for a particular SCEV.
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///
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ConstantRange getUnsignedRange(const SCEV *S);
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ConstantRange getUnsignedRange(const SCEV *S) {
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return getRange(S, HINT_RANGE_UNSIGNED);
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}
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/// getSignedRange - Determine the signed range for a particular SCEV.
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///
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ConstantRange getSignedRange(const SCEV *S);
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ConstantRange getSignedRange(const SCEV *S) {
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return getRange(S, HINT_RANGE_SIGNED);
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}
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/// isKnownNegative - Test if the given expression is known to be negative.
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///
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@ -3868,79 +3868,93 @@ static Optional<ConstantRange> GetRangeFromMetadata(Value *V) {
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return None;
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}
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/// getUnsignedRange - Determine the unsigned range for a particular SCEV.
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/// getRange - Determine the range for a particular SCEV. If SignHint is
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/// HINT_RANGE_UNSIGNED (resp. HINT_RANGE_SIGNED) then getRange prefers ranges
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/// with a "cleaner" unsigned (resp. signed) representation.
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///
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ConstantRange
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ScalarEvolution::getUnsignedRange(const SCEV *S) {
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ScalarEvolution::getRange(const SCEV *S,
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ScalarEvolution::RangeSignHint SignHint) {
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DenseMap<const SCEV *, ConstantRange> &Cache =
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SignHint == ScalarEvolution::HINT_RANGE_UNSIGNED ? UnsignedRanges
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: SignedRanges;
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// See if we've computed this range already.
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DenseMap<const SCEV *, ConstantRange>::iterator I = UnsignedRanges.find(S);
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if (I != UnsignedRanges.end())
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DenseMap<const SCEV *, ConstantRange>::iterator I = Cache.find(S);
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if (I != Cache.end())
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return I->second;
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if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S))
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return setUnsignedRange(C, ConstantRange(C->getValue()->getValue()));
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return setRange(C, SignHint, ConstantRange(C->getValue()->getValue()));
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unsigned BitWidth = getTypeSizeInBits(S->getType());
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ConstantRange ConservativeResult(BitWidth, /*isFullSet=*/true);
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// If the value has known zeros, the maximum unsigned value will have those
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// known zeros as well.
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// If the value has known zeros, the maximum value will have those known zeros
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// as well.
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uint32_t TZ = GetMinTrailingZeros(S);
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if (TZ != 0)
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ConservativeResult =
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ConstantRange(APInt::getMinValue(BitWidth),
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APInt::getMaxValue(BitWidth).lshr(TZ).shl(TZ) + 1);
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if (TZ != 0) {
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if (SignHint == ScalarEvolution::HINT_RANGE_UNSIGNED)
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ConservativeResult =
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ConstantRange(APInt::getMinValue(BitWidth),
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APInt::getMaxValue(BitWidth).lshr(TZ).shl(TZ) + 1);
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else
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ConservativeResult = ConstantRange(
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APInt::getSignedMinValue(BitWidth),
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APInt::getSignedMaxValue(BitWidth).ashr(TZ).shl(TZ) + 1);
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}
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if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(S)) {
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ConstantRange X = getUnsignedRange(Add->getOperand(0));
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ConstantRange X = getRange(Add->getOperand(0), SignHint);
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for (unsigned i = 1, e = Add->getNumOperands(); i != e; ++i)
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X = X.add(getUnsignedRange(Add->getOperand(i)));
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return setUnsignedRange(Add, ConservativeResult.intersectWith(X));
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X = X.add(getRange(Add->getOperand(i), SignHint));
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return setRange(Add, SignHint, ConservativeResult.intersectWith(X));
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}
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if (const SCEVMulExpr *Mul = dyn_cast<SCEVMulExpr>(S)) {
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ConstantRange X = getUnsignedRange(Mul->getOperand(0));
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ConstantRange X = getRange(Mul->getOperand(0), SignHint);
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for (unsigned i = 1, e = Mul->getNumOperands(); i != e; ++i)
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X = X.multiply(getUnsignedRange(Mul->getOperand(i)));
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return setUnsignedRange(Mul, ConservativeResult.intersectWith(X));
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X = X.multiply(getRange(Mul->getOperand(i), SignHint));
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return setRange(Mul, SignHint, ConservativeResult.intersectWith(X));
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}
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if (const SCEVSMaxExpr *SMax = dyn_cast<SCEVSMaxExpr>(S)) {
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ConstantRange X = getUnsignedRange(SMax->getOperand(0));
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ConstantRange X = getRange(SMax->getOperand(0), SignHint);
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for (unsigned i = 1, e = SMax->getNumOperands(); i != e; ++i)
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X = X.smax(getUnsignedRange(SMax->getOperand(i)));
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return setUnsignedRange(SMax, ConservativeResult.intersectWith(X));
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X = X.smax(getRange(SMax->getOperand(i), SignHint));
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return setRange(SMax, SignHint, ConservativeResult.intersectWith(X));
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}
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if (const SCEVUMaxExpr *UMax = dyn_cast<SCEVUMaxExpr>(S)) {
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ConstantRange X = getUnsignedRange(UMax->getOperand(0));
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ConstantRange X = getRange(UMax->getOperand(0), SignHint);
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for (unsigned i = 1, e = UMax->getNumOperands(); i != e; ++i)
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X = X.umax(getUnsignedRange(UMax->getOperand(i)));
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return setUnsignedRange(UMax, ConservativeResult.intersectWith(X));
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X = X.umax(getRange(UMax->getOperand(i), SignHint));
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return setRange(UMax, SignHint, ConservativeResult.intersectWith(X));
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}
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if (const SCEVUDivExpr *UDiv = dyn_cast<SCEVUDivExpr>(S)) {
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ConstantRange X = getUnsignedRange(UDiv->getLHS());
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ConstantRange Y = getUnsignedRange(UDiv->getRHS());
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return setUnsignedRange(UDiv, ConservativeResult.intersectWith(X.udiv(Y)));
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ConstantRange X = getRange(UDiv->getLHS(), SignHint);
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ConstantRange Y = getRange(UDiv->getRHS(), SignHint);
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return setRange(UDiv, SignHint,
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ConservativeResult.intersectWith(X.udiv(Y)));
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}
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if (const SCEVZeroExtendExpr *ZExt = dyn_cast<SCEVZeroExtendExpr>(S)) {
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ConstantRange X = getUnsignedRange(ZExt->getOperand());
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return setUnsignedRange(ZExt,
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ConservativeResult.intersectWith(X.zeroExtend(BitWidth)));
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ConstantRange X = getRange(ZExt->getOperand(), SignHint);
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return setRange(ZExt, SignHint,
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ConservativeResult.intersectWith(X.zeroExtend(BitWidth)));
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}
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if (const SCEVSignExtendExpr *SExt = dyn_cast<SCEVSignExtendExpr>(S)) {
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ConstantRange X = getUnsignedRange(SExt->getOperand());
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return setUnsignedRange(SExt,
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ConservativeResult.intersectWith(X.signExtend(BitWidth)));
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ConstantRange X = getRange(SExt->getOperand(), SignHint);
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return setRange(SExt, SignHint,
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ConservativeResult.intersectWith(X.signExtend(BitWidth)));
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}
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if (const SCEVTruncateExpr *Trunc = dyn_cast<SCEVTruncateExpr>(S)) {
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ConstantRange X = getUnsignedRange(Trunc->getOperand());
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return setUnsignedRange(Trunc,
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ConservativeResult.intersectWith(X.truncate(BitWidth)));
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ConstantRange X = getRange(Trunc->getOperand(), SignHint);
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return setRange(Trunc, SignHint,
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ConservativeResult.intersectWith(X.truncate(BitWidth)));
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}
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if (const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(S)) {
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@ -3953,143 +3967,6 @@ ScalarEvolution::getUnsignedRange(const SCEV *S) {
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ConservativeResult.intersectWith(
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ConstantRange(C->getValue()->getValue(), APInt(BitWidth, 0)));
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// TODO: non-affine addrec
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if (AddRec->isAffine()) {
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Type *Ty = AddRec->getType();
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const SCEV *MaxBECount = getMaxBackedgeTakenCount(AddRec->getLoop());
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if (!isa<SCEVCouldNotCompute>(MaxBECount) &&
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getTypeSizeInBits(MaxBECount->getType()) <= BitWidth) {
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MaxBECount = getNoopOrZeroExtend(MaxBECount, Ty);
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const SCEV *Start = AddRec->getStart();
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const SCEV *Step = AddRec->getStepRecurrence(*this);
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ConstantRange StartRange = getUnsignedRange(Start);
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ConstantRange StepRange = getSignedRange(Step);
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ConstantRange MaxBECountRange = getUnsignedRange(MaxBECount);
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ConstantRange EndRange =
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StartRange.add(MaxBECountRange.multiply(StepRange));
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// Check for overflow. This must be done with ConstantRange arithmetic
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// because we could be called from within the ScalarEvolution overflow
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// checking code.
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ConstantRange ExtStartRange = StartRange.zextOrTrunc(BitWidth*2+1);
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ConstantRange ExtStepRange = StepRange.sextOrTrunc(BitWidth*2+1);
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ConstantRange ExtMaxBECountRange =
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MaxBECountRange.zextOrTrunc(BitWidth*2+1);
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ConstantRange ExtEndRange = EndRange.zextOrTrunc(BitWidth*2+1);
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if (ExtStartRange.add(ExtMaxBECountRange.multiply(ExtStepRange)) !=
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ExtEndRange)
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return setUnsignedRange(AddRec, ConservativeResult);
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APInt Min = APIntOps::umin(StartRange.getUnsignedMin(),
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EndRange.getUnsignedMin());
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APInt Max = APIntOps::umax(StartRange.getUnsignedMax(),
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EndRange.getUnsignedMax());
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if (Min.isMinValue() && Max.isMaxValue())
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return setUnsignedRange(AddRec, ConservativeResult);
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return setUnsignedRange(AddRec,
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ConservativeResult.intersectWith(ConstantRange(Min, Max+1)));
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}
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}
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return setUnsignedRange(AddRec, ConservativeResult);
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}
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if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) {
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// Check if the IR explicitly contains !range metadata.
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Optional<ConstantRange> MDRange = GetRangeFromMetadata(U->getValue());
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if (MDRange.hasValue())
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ConservativeResult = ConservativeResult.intersectWith(MDRange.getValue());
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// For a SCEVUnknown, ask ValueTracking.
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APInt Zeros(BitWidth, 0), Ones(BitWidth, 0);
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computeKnownBits(U->getValue(), Zeros, Ones, DL, 0, AC, nullptr, DT);
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if (Ones == ~Zeros + 1)
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return setUnsignedRange(U, ConservativeResult);
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return setUnsignedRange(U,
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ConservativeResult.intersectWith(ConstantRange(Ones, ~Zeros + 1)));
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}
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return setUnsignedRange(S, ConservativeResult);
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}
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/// getSignedRange - Determine the signed range for a particular SCEV.
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///
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ConstantRange
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ScalarEvolution::getSignedRange(const SCEV *S) {
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// See if we've computed this range already.
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DenseMap<const SCEV *, ConstantRange>::iterator I = SignedRanges.find(S);
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if (I != SignedRanges.end())
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return I->second;
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if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S))
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return setSignedRange(C, ConstantRange(C->getValue()->getValue()));
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unsigned BitWidth = getTypeSizeInBits(S->getType());
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ConstantRange ConservativeResult(BitWidth, /*isFullSet=*/true);
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// If the value has known zeros, the maximum signed value will have those
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// known zeros as well.
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uint32_t TZ = GetMinTrailingZeros(S);
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if (TZ != 0)
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ConservativeResult =
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ConstantRange(APInt::getSignedMinValue(BitWidth),
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APInt::getSignedMaxValue(BitWidth).ashr(TZ).shl(TZ) + 1);
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if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(S)) {
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ConstantRange X = getSignedRange(Add->getOperand(0));
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for (unsigned i = 1, e = Add->getNumOperands(); i != e; ++i)
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X = X.add(getSignedRange(Add->getOperand(i)));
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return setSignedRange(Add, ConservativeResult.intersectWith(X));
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}
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if (const SCEVMulExpr *Mul = dyn_cast<SCEVMulExpr>(S)) {
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ConstantRange X = getSignedRange(Mul->getOperand(0));
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for (unsigned i = 1, e = Mul->getNumOperands(); i != e; ++i)
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X = X.multiply(getSignedRange(Mul->getOperand(i)));
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return setSignedRange(Mul, ConservativeResult.intersectWith(X));
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}
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if (const SCEVSMaxExpr *SMax = dyn_cast<SCEVSMaxExpr>(S)) {
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ConstantRange X = getSignedRange(SMax->getOperand(0));
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for (unsigned i = 1, e = SMax->getNumOperands(); i != e; ++i)
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X = X.smax(getSignedRange(SMax->getOperand(i)));
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return setSignedRange(SMax, ConservativeResult.intersectWith(X));
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}
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if (const SCEVUMaxExpr *UMax = dyn_cast<SCEVUMaxExpr>(S)) {
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ConstantRange X = getSignedRange(UMax->getOperand(0));
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for (unsigned i = 1, e = UMax->getNumOperands(); i != e; ++i)
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X = X.umax(getSignedRange(UMax->getOperand(i)));
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return setSignedRange(UMax, ConservativeResult.intersectWith(X));
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}
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if (const SCEVUDivExpr *UDiv = dyn_cast<SCEVUDivExpr>(S)) {
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ConstantRange X = getSignedRange(UDiv->getLHS());
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ConstantRange Y = getSignedRange(UDiv->getRHS());
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return setSignedRange(UDiv, ConservativeResult.intersectWith(X.udiv(Y)));
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}
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if (const SCEVZeroExtendExpr *ZExt = dyn_cast<SCEVZeroExtendExpr>(S)) {
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ConstantRange X = getSignedRange(ZExt->getOperand());
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return setSignedRange(ZExt,
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ConservativeResult.intersectWith(X.zeroExtend(BitWidth)));
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}
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if (const SCEVSignExtendExpr *SExt = dyn_cast<SCEVSignExtendExpr>(S)) {
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ConstantRange X = getSignedRange(SExt->getOperand());
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return setSignedRange(SExt,
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ConservativeResult.intersectWith(X.signExtend(BitWidth)));
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}
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if (const SCEVTruncateExpr *Trunc = dyn_cast<SCEVTruncateExpr>(S)) {
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ConstantRange X = getSignedRange(Trunc->getOperand());
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return setSignedRange(Trunc,
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ConservativeResult.intersectWith(X.truncate(BitWidth)));
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}
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if (const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(S)) {
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// If there's no signed wrap, and all the operands have the same sign or
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// zero, the value won't ever change sign.
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if (AddRec->getNoWrapFlags(SCEV::FlagNSW)) {
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@ -4115,41 +3992,66 @@ ScalarEvolution::getSignedRange(const SCEV *S) {
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const SCEV *MaxBECount = getMaxBackedgeTakenCount(AddRec->getLoop());
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if (!isa<SCEVCouldNotCompute>(MaxBECount) &&
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getTypeSizeInBits(MaxBECount->getType()) <= BitWidth) {
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// Check for overflow. This must be done with ConstantRange arithmetic
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// because we could be called from within the ScalarEvolution overflow
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// checking code.
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MaxBECount = getNoopOrZeroExtend(MaxBECount, Ty);
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ConstantRange MaxBECountRange = getUnsignedRange(MaxBECount);
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ConstantRange ZExtMaxBECountRange =
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MaxBECountRange.zextOrTrunc(BitWidth * 2 + 1);
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const SCEV *Start = AddRec->getStart();
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const SCEV *Step = AddRec->getStepRecurrence(*this);
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ConstantRange StepSRange = getSignedRange(Step);
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ConstantRange SExtStepSRange = StepSRange.sextOrTrunc(BitWidth * 2 + 1);
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ConstantRange StartRange = getSignedRange(Start);
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ConstantRange StepRange = getSignedRange(Step);
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ConstantRange MaxBECountRange = getUnsignedRange(MaxBECount);
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ConstantRange EndRange =
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StartRange.add(MaxBECountRange.multiply(StepRange));
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ConstantRange StartURange = getUnsignedRange(Start);
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ConstantRange EndURange =
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StartURange.add(MaxBECountRange.multiply(StepSRange));
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// Check for overflow. This must be done with ConstantRange arithmetic
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// because we could be called from within the ScalarEvolution overflow
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// checking code.
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ConstantRange ExtStartRange = StartRange.sextOrTrunc(BitWidth*2+1);
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||||
ConstantRange ExtStepRange = StepRange.sextOrTrunc(BitWidth*2+1);
|
||||
ConstantRange ExtMaxBECountRange =
|
||||
MaxBECountRange.zextOrTrunc(BitWidth*2+1);
|
||||
ConstantRange ExtEndRange = EndRange.sextOrTrunc(BitWidth*2+1);
|
||||
if (ExtStartRange.add(ExtMaxBECountRange.multiply(ExtStepRange)) !=
|
||||
ExtEndRange)
|
||||
return setSignedRange(AddRec, ConservativeResult);
|
||||
// Check for unsigned overflow.
|
||||
ConstantRange ZExtStartURange =
|
||||
StartURange.zextOrTrunc(BitWidth * 2 + 1);
|
||||
ConstantRange ZExtEndURange = EndURange.zextOrTrunc(BitWidth * 2 + 1);
|
||||
if (ZExtStartURange.add(ZExtMaxBECountRange.multiply(SExtStepSRange)) ==
|
||||
ZExtEndURange) {
|
||||
APInt Min = APIntOps::umin(StartURange.getUnsignedMin(),
|
||||
EndURange.getUnsignedMin());
|
||||
APInt Max = APIntOps::umax(StartURange.getUnsignedMax(),
|
||||
EndURange.getUnsignedMax());
|
||||
bool IsFullRange = Min.isMinValue() && Max.isMaxValue();
|
||||
if (!IsFullRange)
|
||||
ConservativeResult =
|
||||
ConservativeResult.intersectWith(ConstantRange(Min, Max + 1));
|
||||
}
|
||||
|
||||
APInt Min = APIntOps::smin(StartRange.getSignedMin(),
|
||||
EndRange.getSignedMin());
|
||||
APInt Max = APIntOps::smax(StartRange.getSignedMax(),
|
||||
EndRange.getSignedMax());
|
||||
if (Min.isMinSignedValue() && Max.isMaxSignedValue())
|
||||
return setSignedRange(AddRec, ConservativeResult);
|
||||
return setSignedRange(AddRec,
|
||||
ConservativeResult.intersectWith(ConstantRange(Min, Max+1)));
|
||||
ConstantRange StartSRange = getSignedRange(Start);
|
||||
ConstantRange EndSRange =
|
||||
StartSRange.add(MaxBECountRange.multiply(StepSRange));
|
||||
|
||||
// Check for signed overflow. This must be done with ConstantRange
|
||||
// arithmetic because we could be called from within the ScalarEvolution
|
||||
// overflow checking code.
|
||||
ConstantRange SExtStartSRange =
|
||||
StartSRange.sextOrTrunc(BitWidth * 2 + 1);
|
||||
ConstantRange SExtEndSRange = EndSRange.sextOrTrunc(BitWidth * 2 + 1);
|
||||
if (SExtStartSRange.add(ZExtMaxBECountRange.multiply(SExtStepSRange)) ==
|
||||
SExtEndSRange) {
|
||||
APInt Min = APIntOps::smin(StartSRange.getSignedMin(),
|
||||
EndSRange.getSignedMin());
|
||||
APInt Max = APIntOps::smax(StartSRange.getSignedMax(),
|
||||
EndSRange.getSignedMax());
|
||||
bool IsFullRange = Min.isMinSignedValue() && Max.isMaxSignedValue();
|
||||
if (!IsFullRange)
|
||||
ConservativeResult =
|
||||
ConservativeResult.intersectWith(ConstantRange(Min, Max + 1));
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return setSignedRange(AddRec, ConservativeResult);
|
||||
return setRange(AddRec, SignHint, ConservativeResult);
|
||||
}
|
||||
|
||||
if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) {
|
||||
@ -4158,18 +4060,33 @@ ScalarEvolution::getSignedRange(const SCEV *S) {
|
||||
if (MDRange.hasValue())
|
||||
ConservativeResult = ConservativeResult.intersectWith(MDRange.getValue());
|
||||
|
||||
// For a SCEVUnknown, ask ValueTracking.
|
||||
if (!U->getValue()->getType()->isIntegerTy() && !DL)
|
||||
return setSignedRange(U, ConservativeResult);
|
||||
unsigned NS = ComputeNumSignBits(U->getValue(), DL, 0, AC, nullptr, DT);
|
||||
if (NS <= 1)
|
||||
return setSignedRange(U, ConservativeResult);
|
||||
return setSignedRange(U, ConservativeResult.intersectWith(
|
||||
ConstantRange(APInt::getSignedMinValue(BitWidth).ashr(NS - 1),
|
||||
APInt::getSignedMaxValue(BitWidth).ashr(NS - 1)+1)));
|
||||
// Split here to avoid paying the compile-time cost of calling both
|
||||
// computeKnownBits and ComputeNumSignBits. This restriction can be lifted
|
||||
// if needed.
|
||||
|
||||
if (SignHint == ScalarEvolution::HINT_RANGE_UNSIGNED) {
|
||||
// For a SCEVUnknown, ask ValueTracking.
|
||||
APInt Zeros(BitWidth, 0), Ones(BitWidth, 0);
|
||||
computeKnownBits(U->getValue(), Zeros, Ones, DL, 0, AC, nullptr, DT);
|
||||
if (Ones != ~Zeros + 1)
|
||||
ConservativeResult =
|
||||
ConservativeResult.intersectWith(ConstantRange(Ones, ~Zeros + 1));
|
||||
} else {
|
||||
assert(SignHint == ScalarEvolution::HINT_RANGE_SIGNED &&
|
||||
"generalize as needed!");
|
||||
if (U->getValue()->getType()->isIntegerTy() || DL) {
|
||||
unsigned NS = ComputeNumSignBits(U->getValue(), DL, 0, AC, nullptr, DT);
|
||||
if (NS > 1)
|
||||
ConservativeResult = ConservativeResult.intersectWith(ConstantRange(
|
||||
APInt::getSignedMinValue(BitWidth).ashr(NS - 1),
|
||||
APInt::getSignedMaxValue(BitWidth).ashr(NS - 1) + 1));
|
||||
}
|
||||
}
|
||||
|
||||
return setRange(U, SignHint, ConservativeResult);
|
||||
}
|
||||
|
||||
return setSignedRange(S, ConservativeResult);
|
||||
return setRange(S, SignHint, ConservativeResult);
|
||||
}
|
||||
|
||||
/// createSCEV - We know that there is no SCEV for the specified value.
|
||||
|
||||
39
test/Analysis/ScalarEvolution/range-signedness.ll
Normal file
39
test/Analysis/ScalarEvolution/range-signedness.ll
Normal file
@ -0,0 +1,39 @@
|
||||
; RUN: opt -analyze -scalar-evolution < %s | FileCheck %s
|
||||
|
||||
define void @x(i1* %cond) {
|
||||
; CHECK-LABEL: Classifying expressions for: @x
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop:
|
||||
%idx = phi i8 [ 0, %entry ], [ %idx.inc, %loop ]
|
||||
; CHECK: %idx = phi i8 [ 0, %entry ], [ %idx.inc, %loop ]
|
||||
; CHECK-NEXT: --> {0,+,1}<nuw><nsw><%loop> U: [0,-128) S: [0,-128)
|
||||
|
||||
%idx.inc = add nsw i8 %idx, 1
|
||||
|
||||
%c = load volatile i1, i1* %cond
|
||||
br i1 %c, label %loop, label %exit
|
||||
|
||||
exit:
|
||||
ret void
|
||||
}
|
||||
|
||||
define void @y(i8* %addr) {
|
||||
; CHECK-LABEL: Classifying expressions for: @y
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop:
|
||||
%idx = phi i8 [-5, %entry ], [ %idx.inc, %loop ]
|
||||
; CHECK: %idx = phi i8 [ -5, %entry ], [ %idx.inc, %loop ]
|
||||
; CHECK-NEXT: --> {-5,+,1}<%loop> U: [-5,6) S: [-5,6)
|
||||
|
||||
%idx.inc = add i8 %idx, 1
|
||||
|
||||
%continue = icmp slt i8 %idx.inc, 6
|
||||
br i1 %continue, label %loop, label %exit
|
||||
|
||||
exit:
|
||||
ret void
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user