[SCEV] Avoid copying ConstantRange just to get the min/max value

[craig.topper]

Summary

This patch changes getRange to getRangeRef and returns a reference to the ConstantRange object stored inside the DenseMap caches. We then take advantage of that to add new helper methods that can return min/max value of a signed or unsigned ConstantRange using that reference without first copying the ConstantRange.

getRangeRef calls itself recursively and I believe the reference return is fine for those calls.

I've left getSignedRange and getUnsignedRange returning a ConstantRange object so they will make a copy now. This is to ensure safety since the reference will be invalidated if the DenseMap changes.

I'm sure there are still more places that can take advantage of the reference and I'll submit future patches as I find them.

[craig.topper]

Ping

[craig.topper]

Ping * 2

[sanjoy]

lgtm

I did not carefully check the getSignedRange(RHS).getSignedMin() -> getSignedRangeMin(RHS) -like transforms, I assumed you got those right.

include/llvm/Analysis/ScalarEvolution.h

const ConstantRange &setRange(const SCEV *S, RangeSignHint Hint,
 
     auto Pair = Cache.try_emplace(S, std::move(CR));
     if (!Pair.second)
       Pair.first->second = std::move(CR);
     return Pair.first->second;
   }
 
   /// Determine the range for a particular SCEV.
-  ConstantRange getRange(const SCEV *S, RangeSignHint Hint);
+  /// NOTE: This returns a reference to an entry in a cache. It must be
+  /// copied if its needed for longer.
+  const ConstantRange &getRangeRef(const SCEV *S, RangeSignHint Hint);
 
   /// Determines the range for the affine SCEVAddRecExpr {\p Start,+,\p Stop}.
   /// Helper for \c getRange.
   ConstantRange getRangeForAffineAR(const SCEV *Start, const SCEV *Stop,
                                     const SCEV *MaxBECount, unsigned BitWidth);
 
   /// Try to compute a range for the affine SCEVAddRecExpr {\p Start,+,\p
   /// Stop} by "factoring out" a ternary expression from the add recurrence.
public:
 
   /// Determine the minimum number of zero bits that S is guaranteed to end in
   /// (at every loop iteration).  It is, at the same time, the minimum number
   /// of times S is divisible by 2.  For example, given {4,+,8} it returns 2.
   /// If S is guaranteed to be 0, it returns the bitwidth of S.
   uint32_t GetMinTrailingZeros(const SCEV *S);
 
   /// Determine the unsigned range for a particular SCEV.
-  ///
+  /// NOTE: This returns a copy of the reference returned by getRangeRef.
   ConstantRange getUnsignedRange(const SCEV *S) {
-    return getRange(S, HINT_RANGE_UNSIGNED);
+    return getRangeRef(S, HINT_RANGE_UNSIGNED);
+  }
+
+  /// Determine the min of the unsigned range for a particular SCEV.
+  APInt getUnsignedRangeMin(const SCEV *S) {
+    return getRangeRef(S, HINT_RANGE_UNSIGNED).getUnsignedMin();
+  }
+
+  /// Determine the max of the unsigned range for a particular SCEV.
+  APInt getUnsignedRangeMax(const SCEV *S) {
+    return getRangeRef(S, HINT_RANGE_UNSIGNED).getUnsignedMax();
   }
 
   /// Determine the signed range for a particular SCEV.
-  ///
+  /// NOTE: This returns a copy of the reference returned by getRangeRef.
   ConstantRange getSignedRange(const SCEV *S) {
-    return getRange(S, HINT_RANGE_SIGNED);
+    return getRangeRef(S, HINT_RANGE_SIGNED);
+  }
+
+  /// Determine the min of the signed range for a particular SCEV.
+  APInt getSignedRangeMin(const SCEV *S) {
+    return getRangeRef(S, HINT_RANGE_SIGNED).getSignedMin();
+  }
+
+  /// Determine the max of the signed range for a particular SCEV.
+  APInt getSignedRangeMax(const SCEV *S) {
+    return getRangeRef(S, HINT_RANGE_SIGNED).getSignedMax();
   }
 
   /// Test if the given expression is known to be negative.
   ///
   bool isKnownNegative(const SCEV *S);
 
   /// Test if the given expression is known to be positive.
   ///

lib/Analysis/ScalarEvolution.cpp

 // loop does not exceed this limit before incrementing.
 static const SCEV *getSignedOverflowLimitForStep(const SCEV *Step,
                                                  ICmpInst::Predicate *Pred,
                                                  ScalarEvolution *SE) {
   unsigned BitWidth = SE->getTypeSizeInBits(Step->getType());
   if (SE->isKnownPositive(Step)) {
     *Pred = ICmpInst::ICMP_SLT;
     return SE->getConstant(APInt::getSignedMinValue(BitWidth) -
-                           SE->getSignedRange(Step).getSignedMax());
+                           SE->getSignedRangeMax(Step));
   }
   if (SE->isKnownNegative(Step)) {
     *Pred = ICmpInst::ICMP_SGT;
     return SE->getConstant(APInt::getSignedMaxValue(BitWidth) -
-                           SE->getSignedRange(Step).getSignedMin());
+                           SE->getSignedRangeMin(Step));
   }
   return nullptr;
 }
 
 // Get the limit of a recurrence such that incrementing by Step cannot cause
 // unsigned overflow as long as the value of the recurrence within the loop does
 // not exceed this limit before incrementing.
 static const SCEV *getUnsignedOverflowLimitForStep(const SCEV *Step,
                                                    ICmpInst::Predicate *Pred,
                                                    ScalarEvolution *SE) {
   unsigned BitWidth = SE->getTypeSizeInBits(Step->getType());
   *Pred = ICmpInst::ICMP_ULT;
 
   return SE->getConstant(APInt::getMinValue(BitWidth) -
-                         SE->getUnsignedRange(Step).getUnsignedMax());
+                         SE->getUnsignedRangeMax(Step));
 }
 
 namespace {
 
 struct ExtendOpTraitsBase {
   typedef const SCEV *(ScalarEvolution::*GetExtendExprTy)(
       const SCEV *, Type *, ScalarEvolution::ExtendCacheTy &Cache);
 };
if (AR->isAffine()) {
           !AC.assumptions().empty()) {
         // If the backedge is guarded by a comparison with the pre-inc
         // value the addrec is safe. Also, if the entry is guarded by
         // a comparison with the start value and the backedge is
         // guarded by a comparison with the post-inc value, the addrec
         // is safe.
         if (isKnownPositive(Step)) {
           const SCEV *N = getConstant(APInt::getMinValue(BitWidth) -
-                                      getUnsignedRange(Step).getUnsignedMax());
+                                      getUnsignedRangeMax(Step));
           if (isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_ULT, AR, N) ||
               (isLoopEntryGuardedByCond(L, ICmpInst::ICMP_ULT, Start, N) &&
                isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_ULT,
                                            AR->getPostIncExpr(*this), N))) {
             // Cache knowledge of AR NUW, which is propagated to this
             // AddRec.
             const_cast<SCEVAddRecExpr *>(AR)->setNoWrapFlags(SCEV::FlagNUW);
             // Return the expression with the addrec on the outside.
             return getAddRecExpr(
                 getExtendAddRecStart<SCEVZeroExtendExpr>(AR, Ty, this, Cache),
                 getZeroExtendExprCached(Step, Ty, Cache), L,
                 AR->getNoWrapFlags());
           }
         } else if (isKnownNegative(Step)) {
           const SCEV *N = getConstant(APInt::getMaxValue(BitWidth) -
-                                      getSignedRange(Step).getSignedMin());
+                                      getSignedRangeMin(Step));
           if (isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_UGT, AR, N) ||
               (isLoopEntryGuardedByCond(L, ICmpInst::ICMP_UGT, Start, N) &&
                isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_UGT,
                                            AR->getPostIncExpr(*this), N))) {
             // Cache knowledge of AR NW, which is propagated to this
             // AddRec.  Negative step causes unsigned wrap, but it
             // still can't self-wrap.
             const_cast<SCEVAddRecExpr *>(AR)->setNoWrapFlags(SCEV::FlagNW);
const SCEV *ScalarEvolution::getMinusSCEV(const SCEV *LHS, const SCEV *RHS,
   // Fast path: X - X --> 0.
   if (LHS == RHS)
     return getZero(LHS->getType());
 
   // We represent LHS - RHS as LHS + (-1)*RHS. This transformation
   // makes it so that we cannot make much use of NUW.
   auto AddFlags = SCEV::FlagAnyWrap;
   const bool RHSIsNotMinSigned =
-      !getSignedRange(RHS).getSignedMin().isMinSignedValue();
+      !getSignedRangeMin(RHS).isMinSignedValue();
   if (maskFlags(Flags, SCEV::FlagNSW) == SCEV::FlagNSW) {
     // Let M be the minimum representable signed value. Then (-1)*RHS
     // signed-wraps if and only if RHS is M. That can happen even for
     // a NSW subtraction because e.g. (-1)*M signed-wraps even though
     // -1 - M does not. So to transfer NSW from LHS - RHS to LHS +
     // (-1)*RHS, we need to prove that RHS != M.
     //
     // If LHS is non-negative and we know that LHS - RHS does not
if (MDNode *MD = I->getMetadata(LLVMContext::MD_range))
       return getConstantRangeFromMetadata(*MD);
 
   return None;
 }
 
 /// Determine the range for a particular SCEV.  If SignHint is
 /// HINT_RANGE_UNSIGNED (resp. HINT_RANGE_SIGNED) then getRange prefers ranges
 /// with a "cleaner" unsigned (resp. signed) representation.
-ConstantRange
-ScalarEvolution::getRange(const SCEV *S,
+const ConstantRange &
+ScalarEvolution::getRangeRef(const SCEV *S,
                              ScalarEvolution::RangeSignHint SignHint) {
   DenseMap<const SCEV *, ConstantRange> &Cache =
       SignHint == ScalarEvolution::HINT_RANGE_UNSIGNED ? UnsignedRanges
                                                        : SignedRanges;
 
   // See if we've computed this range already.
   DenseMap<const SCEV *, ConstantRange>::iterator I = Cache.find(S);
   if (I != Cache.end())
     return I->second;
if (SignHint == ScalarEvolution::HINT_RANGE_UNSIGNED)
                         APInt::getMaxValue(BitWidth).lshr(TZ).shl(TZ) + 1);
     else
       ConservativeResult = ConstantRange(
           APInt::getSignedMinValue(BitWidth),
           APInt::getSignedMaxValue(BitWidth).ashr(TZ).shl(TZ) + 1);
   }
 
   if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(S)) {
-    ConstantRange X = getRange(Add->getOperand(0), SignHint);
+    ConstantRange X = getRangeRef(Add->getOperand(0), SignHint);
     for (unsigned i = 1, e = Add->getNumOperands(); i != e; ++i)
-      X = X.add(getRange(Add->getOperand(i), SignHint));
+      X = X.add(getRangeRef(Add->getOperand(i), SignHint));
     return setRange(Add, SignHint, ConservativeResult.intersectWith(X));
   }
 
   if (const SCEVMulExpr *Mul = dyn_cast<SCEVMulExpr>(S)) {
-    ConstantRange X = getRange(Mul->getOperand(0), SignHint);
+    ConstantRange X = getRangeRef(Mul->getOperand(0), SignHint);
     for (unsigned i = 1, e = Mul->getNumOperands(); i != e; ++i)
-      X = X.multiply(getRange(Mul->getOperand(i), SignHint));
+      X = X.multiply(getRangeRef(Mul->getOperand(i), SignHint));
     return setRange(Mul, SignHint, ConservativeResult.intersectWith(X));
   }
 
   if (const SCEVSMaxExpr *SMax = dyn_cast<SCEVSMaxExpr>(S)) {
-    ConstantRange X = getRange(SMax->getOperand(0), SignHint);
+    ConstantRange X = getRangeRef(SMax->getOperand(0), SignHint);
     for (unsigned i = 1, e = SMax->getNumOperands(); i != e; ++i)
-      X = X.smax(getRange(SMax->getOperand(i), SignHint));
+      X = X.smax(getRangeRef(SMax->getOperand(i), SignHint));
     return setRange(SMax, SignHint, ConservativeResult.intersectWith(X));
   }
 
   if (const SCEVUMaxExpr *UMax = dyn_cast<SCEVUMaxExpr>(S)) {
-    ConstantRange X = getRange(UMax->getOperand(0), SignHint);
+    ConstantRange X = getRangeRef(UMax->getOperand(0), SignHint);
     for (unsigned i = 1, e = UMax->getNumOperands(); i != e; ++i)
-      X = X.umax(getRange(UMax->getOperand(i), SignHint));
+      X = X.umax(getRangeRef(UMax->getOperand(i), SignHint));
     return setRange(UMax, SignHint, ConservativeResult.intersectWith(X));
   }
 
   if (const SCEVUDivExpr *UDiv = dyn_cast<SCEVUDivExpr>(S)) {
-    ConstantRange X = getRange(UDiv->getLHS(), SignHint);
-    ConstantRange Y = getRange(UDiv->getRHS(), SignHint);
+    ConstantRange X = getRangeRef(UDiv->getLHS(), SignHint);
+    ConstantRange Y = getRangeRef(UDiv->getRHS(), SignHint);
     return setRange(UDiv, SignHint,
                     ConservativeResult.intersectWith(X.udiv(Y)));
   }
 
   if (const SCEVZeroExtendExpr *ZExt = dyn_cast<SCEVZeroExtendExpr>(S)) {
-    ConstantRange X = getRange(ZExt->getOperand(), SignHint);
+    ConstantRange X = getRangeRef(ZExt->getOperand(), SignHint);
     return setRange(ZExt, SignHint,
                     ConservativeResult.intersectWith(X.zeroExtend(BitWidth)));
   }
 
   if (const SCEVSignExtendExpr *SExt = dyn_cast<SCEVSignExtendExpr>(S)) {
-    ConstantRange X = getRange(SExt->getOperand(), SignHint);
+    ConstantRange X = getRangeRef(SExt->getOperand(), SignHint);
     return setRange(SExt, SignHint,
                     ConservativeResult.intersectWith(X.signExtend(BitWidth)));
   }
 
   if (const SCEVTruncateExpr *Trunc = dyn_cast<SCEVTruncateExpr>(S)) {
-    ConstantRange X = getRange(Trunc->getOperand(), SignHint);
+    ConstantRange X = getRangeRef(Trunc->getOperand(), SignHint);
     return setRange(Trunc, SignHint,
                     ConservativeResult.intersectWith(X.truncate(BitWidth)));
   }
 
   if (const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(S)) {
     // If there's no unsigned wrap, the value will never be less than its
     // initial value.
     if (AddRec->hasNoUnsignedWrap())
ConstantRange ScalarEvolution::getRangeForAffineAR(const SCEV *Start,
                                                    const SCEV *Step,
                                                    const SCEV *MaxBECount,
                                                    unsigned BitWidth) {
   assert(!isa<SCEVCouldNotCompute>(MaxBECount) &&
          getTypeSizeInBits(MaxBECount->getType()) <= BitWidth &&
          "Precondition!");
 
   MaxBECount = getNoopOrZeroExtend(MaxBECount, Start->getType());
-  ConstantRange MaxBECountRange = getUnsignedRange(MaxBECount);
-  APInt MaxBECountValue = MaxBECountRange.getUnsignedMax();
+  APInt MaxBECountValue = getUnsignedRangeMax(MaxBECount);
 
   // First, consider step signed.
   ConstantRange StartSRange = getSignedRange(Start);
   ConstantRange StepSRange = getSignedRange(Step);
 
   // If Step can be both positive and negative, we need to find ranges for the
   // maximum absolute step values in both directions and union them.
   ConstantRange SR =
       getRangeForAffineARHelper(StepSRange.getSignedMin(), StartSRange,
                                 MaxBECountValue, BitWidth, /* Signed = */ true);
   SR = SR.unionWith(getRangeForAffineARHelper(StepSRange.getSignedMax(),
                                               StartSRange, MaxBECountValue,
                                               BitWidth, /* Signed = */ true));
 
   // Next, consider step unsigned.
   ConstantRange UR = getRangeForAffineARHelper(
-      getUnsignedRange(Step).getUnsignedMax(), getUnsignedRange(Start),
+      getUnsignedRangeMax(Step), getUnsignedRange(Start),
       MaxBECountValue, BitWidth, /* Signed = */ false);
 
   // Finally, intersect signed and unsigned ranges.
   return SR.intersectWith(UR);
 }
 
 ConstantRange ScalarEvolution::getRangeViaFactoring(const SCEV *Start,
                                                     const SCEV *Step,
ScalarEvolution::howFarToZero(const SCEV *V, const Loop *L, bool ControlsExit,
   // First compute the unsigned distance from zero in the direction of Step.
   bool CountDown = StepC->getAPInt().isNegative();
   const SCEV *Distance = CountDown ? Start : getNegativeSCEV(Start);
 
   // Handle unitary steps, which cannot wraparound.
   // 1*N = -Start; -1*N = Start (mod 2^BW), so:
   //   N = Distance (as unsigned)
   if (StepC->getValue()->equalsInt(1) || StepC->getValue()->isAllOnesValue()) {
-    APInt MaxBECount = getUnsignedRange(Distance).getUnsignedMax();
+    APInt MaxBECount = getUnsignedRangeMax(Distance);
 
     // When a loop like "for (int i = 0; i != n; ++i) { /* body */ }" is rotated,
     // we end up with a loop whose backedge-taken count is n - 1.  Detect this
     // case, and see if we can improve the bound.
     //
     // Explicitly handling this here is necessary because getUnsignedRange
     // isn't context-sensitive; it doesn't know that we only care about the
     // range inside the loop.
if (HasSameValue(LHS, RHS)) {
     if (ICmpInst::isFalseWhenEqual(Pred))
       goto trivially_false;
   }
 
   // If possible, canonicalize GE/LE comparisons to GT/LT comparisons, by
   // adding or subtracting 1 from one of the operands.
   switch (Pred) {
   case ICmpInst::ICMP_SLE:
-    if (!getSignedRange(RHS).getSignedMax().isMaxSignedValue()) {
+    if (!getSignedRangeMax(RHS).isMaxSignedValue()) {
       RHS = getAddExpr(getConstant(RHS->getType(), 1, true), RHS,
                        SCEV::FlagNSW);
       Pred = ICmpInst::ICMP_SLT;
       Changed = true;
-    } else if (!getSignedRange(LHS).getSignedMin().isMinSignedValue()) {
+    } else if (!getSignedRangeMin(LHS).isMinSignedValue()) {
       LHS = getAddExpr(getConstant(RHS->getType(), (uint64_t)-1, true), LHS,
                        SCEV::FlagNSW);
       Pred = ICmpInst::ICMP_SLT;
       Changed = true;
     }
     break;
   case ICmpInst::ICMP_SGE:
-    if (!getSignedRange(RHS).getSignedMin().isMinSignedValue()) {
+    if (!getSignedRangeMin(RHS).isMinSignedValue()) {
       RHS = getAddExpr(getConstant(RHS->getType(), (uint64_t)-1, true), RHS,
                        SCEV::FlagNSW);
       Pred = ICmpInst::ICMP_SGT;
       Changed = true;
-    } else if (!getSignedRange(LHS).getSignedMax().isMaxSignedValue()) {
+    } else if (!getSignedRangeMax(LHS).isMaxSignedValue()) {
       LHS = getAddExpr(getConstant(RHS->getType(), 1, true), LHS,
                        SCEV::FlagNSW);
       Pred = ICmpInst::ICMP_SGT;
       Changed = true;
     }
     break;
   case ICmpInst::ICMP_ULE:
-    if (!getUnsignedRange(RHS).getUnsignedMax().isMaxValue()) {
+    if (!getUnsignedRangeMax(RHS).isMaxValue()) {
       RHS = getAddExpr(getConstant(RHS->getType(), 1, true), RHS,
                        SCEV::FlagNUW);
       Pred = ICmpInst::ICMP_ULT;
       Changed = true;
-    } else if (!getUnsignedRange(LHS).getUnsignedMin().isMinValue()) {
+    } else if (!getUnsignedRangeMin(LHS).isMinValue()) {
       LHS = getAddExpr(getConstant(RHS->getType(), (uint64_t)-1, true), LHS);
       Pred = ICmpInst::ICMP_ULT;
       Changed = true;
     }
     break;
   case ICmpInst::ICMP_UGE:
-    if (!getUnsignedRange(RHS).getUnsignedMin().isMinValue()) {
+    if (!getUnsignedRangeMin(RHS).isMinValue()) {
       RHS = getAddExpr(getConstant(RHS->getType(), (uint64_t)-1, true), RHS);
       Pred = ICmpInst::ICMP_UGT;
       Changed = true;
-    } else if (!getUnsignedRange(LHS).getUnsignedMax().isMaxValue()) {
+    } else if (!getUnsignedRangeMax(LHS).isMaxValue()) {
       LHS = getAddExpr(getConstant(RHS->getType(), 1, true), LHS,
                        SCEV::FlagNUW);
       Pred = ICmpInst::ICMP_UGT;
       Changed = true;
     }
     break;
   default:
     break;

 trivially_false:
   // Return 0 != 0.
   LHS = RHS = getConstant(ConstantInt::getFalse(getContext()));
   Pred = ICmpInst::ICMP_NE;
   return true;
 }
 
 bool ScalarEvolution::isKnownNegative(const SCEV *S) {
-  return getSignedRange(S).getSignedMax().isNegative();
+  return getSignedRangeMax(S).isNegative();
 }
 
 bool ScalarEvolution::isKnownPositive(const SCEV *S) {
-  return getSignedRange(S).getSignedMin().isStrictlyPositive();
+  return getSignedRangeMin(S).isStrictlyPositive();
 }
 
 bool ScalarEvolution::isKnownNonNegative(const SCEV *S) {
-  return !getSignedRange(S).getSignedMin().isNegative();
+  return !getSignedRangeMin(S).isNegative();
 }
 
 bool ScalarEvolution::isKnownNonPositive(const SCEV *S) {
-  return !getSignedRange(S).getSignedMax().isStrictlyPositive();
+  return !getSignedRangeMax(S).isStrictlyPositive();
 }
 
 bool ScalarEvolution::isKnownNonZero(const SCEV *S) {
   return isKnownNegative(S) || isKnownPositive(S);
 }
 
 bool ScalarEvolution::isKnownPredicate(ICmpInst::Predicate Pred,
                                        const SCEV *LHS, const SCEV *RHS) {
if (FoundPred == ICmpInst::ICMP_NE &&
     }
 
     // The guarding predicate tells us that C != V. If the known range
     // of V is [C, t), we can sharpen the range to [C + 1, t).  The
     // range we consider has to correspond to same signedness as the
     // predicate we're interested in folding.
 
     APInt Min = ICmpInst::isSigned(Pred) ?
-        getSignedRange(V).getSignedMin() : getUnsignedRange(V).getUnsignedMin();
+        getSignedRangeMin(V) : getUnsignedRangeMin(V);
 
     if (Min == C->getAPInt()) {
       // Given (V >= Min && V != Min) we conclude V >= (Min + 1).
       // This is true even if (Min + 1) wraps around -- in case of
       // wraparound, (Min + 1) < Min, so (V >= Min => V >= (Min + 1)).
 
       APInt SharperMin = Min + 1;
 
bool ScalarEvolution::doesIVOverflowOnLT(const SCEV *RHS, const SCEV *Stride,
   assert(isKnownPositive(Stride) && "Positive stride expected!");
 
   if (NoWrap) return false;
 
   unsigned BitWidth = getTypeSizeInBits(RHS->getType());
   const SCEV *One = getOne(Stride->getType());
 
   if (IsSigned) {
-    APInt MaxRHS = getSignedRange(RHS).getSignedMax();
+    APInt MaxRHS = getSignedRangeMax(RHS);
     APInt MaxValue = APInt::getSignedMaxValue(BitWidth);
-    APInt MaxStrideMinusOne = getSignedRange(getMinusSCEV(Stride, One))
-                                .getSignedMax();
+    APInt MaxStrideMinusOne = getSignedRangeMax(getMinusSCEV(Stride, One));
 
     // SMaxRHS + SMaxStrideMinusOne > SMaxValue => overflow!
     return (std::move(MaxValue) - MaxStrideMinusOne).slt(MaxRHS);
   }
 
-  APInt MaxRHS = getUnsignedRange(RHS).getUnsignedMax();
+  APInt MaxRHS = getUnsignedRangeMax(RHS);
   APInt MaxValue = APInt::getMaxValue(BitWidth);
-  APInt MaxStrideMinusOne = getUnsignedRange(getMinusSCEV(Stride, One))
-                              .getUnsignedMax();
+  APInt MaxStrideMinusOne = getUnsignedRangeMax(getMinusSCEV(Stride, One));
 
   // UMaxRHS + UMaxStrideMinusOne > UMaxValue => overflow!
   return (std::move(MaxValue) - MaxStrideMinusOne).ult(MaxRHS);
 }
 
 bool ScalarEvolution::doesIVOverflowOnGT(const SCEV *RHS, const SCEV *Stride,
                                          bool IsSigned, bool NoWrap) {
   if (NoWrap) return false;
 
   unsigned BitWidth = getTypeSizeInBits(RHS->getType());
   const SCEV *One = getOne(Stride->getType());
 
   if (IsSigned) {
-    APInt MinRHS = getSignedRange(RHS).getSignedMin();
+    APInt MinRHS = getSignedRangeMin(RHS);
     APInt MinValue = APInt::getSignedMinValue(BitWidth);
-    APInt MaxStrideMinusOne = getSignedRange(getMinusSCEV(Stride, One))
-                               .getSignedMax();
+    APInt MaxStrideMinusOne = getSignedRangeMax(getMinusSCEV(Stride, One));
 
     // SMinRHS - SMaxStrideMinusOne < SMinValue => overflow!
     return (std::move(MinValue) + MaxStrideMinusOne).sgt(MinRHS);
   }
 
-  APInt MinRHS = getUnsignedRange(RHS).getUnsignedMin();
+  APInt MinRHS = getUnsignedRangeMin(RHS);
   APInt MinValue = APInt::getMinValue(BitWidth);
-  APInt MaxStrideMinusOne = getUnsignedRange(getMinusSCEV(Stride, One))
-                            .getUnsignedMax();
+  APInt MaxStrideMinusOne = getUnsignedRangeMax(getMinusSCEV(Stride, One));
 
   // UMinRHS - UMaxStrideMinusOne < UMinValue => overflow!
   return (std::move(MinValue) + MaxStrideMinusOne).ugt(MinRHS);
 }
 
 const SCEV *ScalarEvolution::computeBECount(const SCEV *Delta, const SCEV *Step,
                                             bool Equality) {
   const SCEV *One = getOne(Step->getType());
else if (isa<SCEVConstant>(BECountIfBackedgeTaken)) {
     // If we know exactly how many times the backedge will be taken if it's
     // taken at least once, then the backedge count will either be that or
     // zero.
     MaxBECount = BECountIfBackedgeTaken;
     MaxOrZero = true;
   } else {
     // Calculate the maximum backedge count based on the range of values
     // permitted by Start, End, and Stride.
-    APInt MinStart = IsSigned ? getSignedRange(Start).getSignedMin()
-                              : getUnsignedRange(Start).getUnsignedMin();
+    APInt MinStart = IsSigned ? getSignedRangeMin(Start)
+                              : getUnsignedRangeMin(Start);
 
     unsigned BitWidth = getTypeSizeInBits(LHS->getType());
 
     APInt StrideForMaxBECount;
 
     if (PositiveStride)
       StrideForMaxBECount =
-        IsSigned ? getSignedRange(Stride).getSignedMin()
-                 : getUnsignedRange(Stride).getUnsignedMin();
+        IsSigned ? getSignedRangeMin(Stride)
+                 : getUnsignedRangeMin(Stride);
     else
       // Using a stride of 1 is safe when computing max backedge taken count for
       // a loop with unknown stride.
       StrideForMaxBECount = APInt(BitWidth, 1, IsSigned);
 
     APInt Limit =
       IsSigned ? APInt::getSignedMaxValue(BitWidth) - (StrideForMaxBECount - 1)
                : APInt::getMaxValue(BitWidth) - (StrideForMaxBECount - 1);
 
     // Although End can be a MAX expression we estimate MaxEnd considering only
     // the case End = RHS. This is safe because in the other case (End - Start)
     // is zero, leading to a zero maximum backedge taken count.
     APInt MaxEnd =
-      IsSigned ? APIntOps::smin(getSignedRange(RHS).getSignedMax(), Limit)
-               : APIntOps::umin(getUnsignedRange(RHS).getUnsignedMax(), Limit);
+      IsSigned ? APIntOps::smin(getSignedRangeMax(RHS), Limit)
+               : APIntOps::umin(getUnsignedRangeMax(RHS), Limit);
 
     MaxBECount = computeBECount(getConstant(MaxEnd - MinStart),
                                 getConstant(StrideForMaxBECount), false);
   }
 
   if (isa<SCEVCouldNotCompute>(MaxBECount))
     MaxBECount = BECount;
 
ScalarEvolution::howManyGreaterThans(const SCEV *LHS, const SCEV *RHS,
 
   const SCEV *Start = IV->getStart();
   const SCEV *End = RHS;
   if (!isLoopEntryGuardedByCond(L, Cond, getAddExpr(Start, Stride), RHS))
     End = IsSigned ? getSMinExpr(RHS, Start) : getUMinExpr(RHS, Start);
 
   const SCEV *BECount = computeBECount(getMinusSCEV(Start, End), Stride, false);
 
-  APInt MaxStart = IsSigned ? getSignedRange(Start).getSignedMax()
-                            : getUnsignedRange(Start).getUnsignedMax();
+  APInt MaxStart = IsSigned ? getSignedRangeMax(Start)
+                            : getUnsignedRangeMax(Start);
 
-  APInt MinStride = IsSigned ? getSignedRange(Stride).getSignedMin()
-                             : getUnsignedRange(Stride).getUnsignedMin();
+  APInt MinStride = IsSigned ? getSignedRangeMin(Stride)
+                             : getUnsignedRangeMin(Stride);
 
   unsigned BitWidth = getTypeSizeInBits(LHS->getType());
   APInt Limit = IsSigned ? APInt::getSignedMinValue(BitWidth) + (MinStride - 1)
                          : APInt::getMinValue(BitWidth) + (MinStride - 1);
 
   // Although End can be a MIN expression we estimate MinEnd considering only
   // the case End = RHS. This is safe because in the other case (Start - End)
   // is zero, leading to a zero maximum backedge taken count.
   APInt MinEnd =
-    IsSigned ? APIntOps::smax(getSignedRange(RHS).getSignedMin(), Limit)
-             : APIntOps::umax(getUnsignedRange(RHS).getUnsignedMin(), Limit);
+    IsSigned ? APIntOps::smax(getSignedRangeMin(RHS), Limit)
+             : APIntOps::umax(getUnsignedRangeMin(RHS), Limit);
 
 
   const SCEV *MaxBECount = getCouldNotCompute();
   if (isa<SCEVConstant>(BECount))
     MaxBECount = BECount;
   else
     MaxBECount = computeBECount(getConstant(MaxStart - MinEnd),
                                 getConstant(MinStride), false);