[llvm] r278828 - [InstCombine] add helper functions for foldICmpWithConstant; NFCI

Sanjay Patel via llvm-commits llvm-commits at lists.llvm.org
Tue Aug 16 10:54:36 PDT 2016


Author: spatel
Date: Tue Aug 16 12:54:36 2016
New Revision: 278828

URL: http://llvm.org/viewvc/llvm-project?rev=278828&view=rev
Log:
[InstCombine] add helper functions for foldICmpWithConstant; NFCI

Besides breaking up a 700 line function to improve readability,
this sinks the 'FIXME: ConstantInt' check into each helper. So 
now we can independently break that restriction within any of the
helper functions.

As much as possible, the code was only {cut/paste/clang-format}'ed 
to minimize risk (no functional changes intended), so several more
readability improvements are still possible. 


Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
    llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp?rev=278828&r1=278827&r2=278828&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp Tue Aug 16 12:54:36 2016
@@ -1179,8 +1179,9 @@ Instruction *InstCombiner::foldICmpAddOp
 
 /// Fold "icmp pred, ([su]div X, DivRHS), CmpRHS" where DivRHS and CmpRHS are
 /// both known to be integer constants.
-Instruction *InstCombiner::foldICmpDivConst(ICmpInst &ICI, BinaryOperator *DivI,
-                                            ConstantInt *DivRHS) {
+Instruction *InstCombiner::foldICmpDivConstConst(ICmpInst &ICI,
+                                                 BinaryOperator *DivI,
+                                                 ConstantInt *DivRHS) {
   ConstantInt *CmpRHS = cast<ConstantInt>(ICI.getOperand(1));
   const APInt &CmpRHSV = CmpRHS->getValue();
 
@@ -1335,8 +1336,9 @@ Instruction *InstCombiner::foldICmpDivCo
 }
 
 /// Handle "icmp(([al]shr X, cst1), cst2)".
-Instruction *InstCombiner::foldICmpShrConst(ICmpInst &ICI, BinaryOperator *Shr,
-                                            ConstantInt *ShAmt) {
+Instruction *InstCombiner::foldICmpShrConstConst(ICmpInst &ICI,
+                                                 BinaryOperator *Shr,
+                                                 ConstantInt *ShAmt) {
   const APInt &CmpRHSV = cast<ConstantInt>(ICI.getOperand(1))->getValue();
 
   // Check that the shift amount is in range.  If not, don't perform
@@ -1382,7 +1384,8 @@ Instruction *InstCombiner::foldICmpShrCo
     assert(TheDiv->getOpcode() == Instruction::SDiv ||
            TheDiv->getOpcode() == Instruction::UDiv);
 
-    Instruction *Res = foldICmpDivConst(ICI, TheDiv, cast<ConstantInt>(DivCst));
+    Instruction *Res =
+        foldICmpDivConstConst(ICI, TheDiv, cast<ConstantInt>(DivCst));
     assert(Res && "This div/cst should have folded!");
     return Res;
   }
@@ -1530,672 +1533,782 @@ Instruction *InstCombiner::foldICmpCstSh
   return getConstant(false);
 }
 
-/// Try to fold integer comparisons with a constant operand: icmp Pred X, C.
-Instruction *InstCombiner::foldICmpWithConstant(ICmpInst &ICI) {
-  Instruction *LHSI;
-  const APInt *RHSV;
-  if (!match(ICI.getOperand(0), m_Instruction(LHSI)) ||
-      !match(ICI.getOperand(1), m_APInt(RHSV)))
-    return nullptr;
-
+Instruction *InstCombiner::foldICmpTruncConstant(ICmpInst &ICI,
+                                                 Instruction *LHSI,
+                                                 const APInt *RHSV) {
   // FIXME: This check restricts all folds under here to scalar types.
   ConstantInt *RHS = dyn_cast<ConstantInt>(ICI.getOperand(1));
   if (!RHS)
     return nullptr;
 
-  switch (LHSI->getOpcode()) {
-  case Instruction::Trunc:
-    if (RHS->isOne() && RHSV->getBitWidth() > 1) {
-      // icmp slt trunc(signum(V)) 1 --> icmp slt V, 1
-      Value *V = nullptr;
-      if (ICI.getPredicate() == ICmpInst::ICMP_SLT &&
-          match(LHSI->getOperand(0), m_Signum(m_Value(V))))
-        return new ICmpInst(ICmpInst::ICMP_SLT, V,
-                            ConstantInt::get(V->getType(), 1));
-    }
-    if (ICI.isEquality() && LHSI->hasOneUse()) {
-      // Simplify icmp eq (trunc x to i8), 42 -> icmp eq x, 42|highbits if all
-      // of the high bits truncated out of x are known.
-      unsigned DstBits = LHSI->getType()->getPrimitiveSizeInBits(),
+  if (RHS->isOne() && RHSV->getBitWidth() > 1) {
+    // icmp slt trunc(signum(V)) 1 --> icmp slt V, 1
+    Value *V = nullptr;
+    if (ICI.getPredicate() == ICmpInst::ICMP_SLT &&
+        match(LHSI->getOperand(0), m_Signum(m_Value(V))))
+      return new ICmpInst(ICmpInst::ICMP_SLT, V,
+                          ConstantInt::get(V->getType(), 1));
+  }
+  if (ICI.isEquality() && LHSI->hasOneUse()) {
+    // Simplify icmp eq (trunc x to i8), 42 -> icmp eq x, 42|highbits if all
+    // of the high bits truncated out of x are known.
+    unsigned DstBits = LHSI->getType()->getPrimitiveSizeInBits(),
              SrcBits = LHSI->getOperand(0)->getType()->getPrimitiveSizeInBits();
-      APInt KnownZero(SrcBits, 0), KnownOne(SrcBits, 0);
-      computeKnownBits(LHSI->getOperand(0), KnownZero, KnownOne, 0, &ICI);
+    APInt KnownZero(SrcBits, 0), KnownOne(SrcBits, 0);
+    computeKnownBits(LHSI->getOperand(0), KnownZero, KnownOne, 0, &ICI);
 
-      // If all the high bits are known, we can do this xform.
-      if ((KnownZero|KnownOne).countLeadingOnes() >= SrcBits-DstBits) {
-        // Pull in the high bits from known-ones set.
-        APInt NewRHS = RHS->getValue().zext(SrcBits);
-        NewRHS |= KnownOne & APInt::getHighBitsSet(SrcBits, SrcBits-DstBits);
-        return new ICmpInst(ICI.getPredicate(), LHSI->getOperand(0),
-                            Builder->getInt(NewRHS));
-      }
+    // If all the high bits are known, we can do this xform.
+    if ((KnownZero | KnownOne).countLeadingOnes() >= SrcBits - DstBits) {
+      // Pull in the high bits from known-ones set.
+      APInt NewRHS = RHS->getValue().zext(SrcBits);
+      NewRHS |= KnownOne & APInt::getHighBitsSet(SrcBits, SrcBits - DstBits);
+      return new ICmpInst(ICI.getPredicate(), LHSI->getOperand(0),
+                          Builder->getInt(NewRHS));
     }
-    break;
+  }
+  return nullptr;
+}
 
-  case Instruction::Xor:         // (icmp pred (xor X, XorCst), CI)
-    if (ConstantInt *XorCst = dyn_cast<ConstantInt>(LHSI->getOperand(1))) {
-      // If this is a comparison that tests the signbit (X < 0) or (x > -1),
-      // fold the xor.
-      if ((ICI.getPredicate() == ICmpInst::ICMP_SLT && *RHSV == 0) ||
-          (ICI.getPredicate() == ICmpInst::ICMP_SGT && RHSV->isAllOnesValue())) {
-        Value *CompareVal = LHSI->getOperand(0);
-
-        // If the sign bit of the XorCst is not set, there is no change to
-        // the operation, just stop using the Xor.
-        if (!XorCst->isNegative()) {
-          ICI.setOperand(0, CompareVal);
-          Worklist.Add(LHSI);
-          return &ICI;
-        }
+Instruction *InstCombiner::foldICmpXorConstant(ICmpInst &ICI, Instruction *LHSI,
+                                               const APInt *RHSV) {
+  // FIXME: This check restricts all folds under here to scalar types.
+  ConstantInt *RHS = dyn_cast<ConstantInt>(ICI.getOperand(1));
+  if (!RHS)
+    return nullptr;
 
-        // Was the old condition true if the operand is positive?
-        bool isTrueIfPositive = ICI.getPredicate() == ICmpInst::ICMP_SGT;
+  if (ConstantInt *XorCst = dyn_cast<ConstantInt>(LHSI->getOperand(1))) {
+    // If this is a comparison that tests the signbit (X < 0) or (x > -1),
+    // fold the xor.
+    if ((ICI.getPredicate() == ICmpInst::ICMP_SLT && *RHSV == 0) ||
+        (ICI.getPredicate() == ICmpInst::ICMP_SGT && RHSV->isAllOnesValue())) {
+      Value *CompareVal = LHSI->getOperand(0);
+
+      // If the sign bit of the XorCst is not set, there is no change to
+      // the operation, just stop using the Xor.
+      if (!XorCst->isNegative()) {
+        ICI.setOperand(0, CompareVal);
+        Worklist.Add(LHSI);
+        return &ICI;
+      }
 
-        // If so, the new one isn't.
-        isTrueIfPositive ^= true;
+      // Was the old condition true if the operand is positive?
+      bool isTrueIfPositive = ICI.getPredicate() == ICmpInst::ICMP_SGT;
 
-        if (isTrueIfPositive)
-          return new ICmpInst(ICmpInst::ICMP_SGT, CompareVal,
-                              SubOne(RHS));
-        else
-          return new ICmpInst(ICmpInst::ICMP_SLT, CompareVal,
-                              AddOne(RHS));
-      }
+      // If so, the new one isn't.
+      isTrueIfPositive ^= true;
 
-      if (LHSI->hasOneUse()) {
-        // (icmp u/s (xor A SignBit), C) -> (icmp s/u A, (xor C SignBit))
-        if (!ICI.isEquality() && XorCst->getValue().isSignBit()) {
-          const APInt &SignBit = XorCst->getValue();
-          ICmpInst::Predicate Pred = ICI.isSigned()
-                                         ? ICI.getUnsignedPredicate()
-                                         : ICI.getSignedPredicate();
-          return new ICmpInst(Pred, LHSI->getOperand(0),
-                              Builder->getInt(*RHSV ^ SignBit));
-        }
+      if (isTrueIfPositive)
+        return new ICmpInst(ICmpInst::ICMP_SGT, CompareVal, SubOne(RHS));
+      else
+        return new ICmpInst(ICmpInst::ICMP_SLT, CompareVal, AddOne(RHS));
+    }
 
-        // (icmp u/s (xor A ~SignBit), C) -> (icmp s/u (xor C ~SignBit), A)
-        if (!ICI.isEquality() && XorCst->isMaxValue(true)) {
-          const APInt &NotSignBit = XorCst->getValue();
-          ICmpInst::Predicate Pred = ICI.isSigned()
-                                         ? ICI.getUnsignedPredicate()
-                                         : ICI.getSignedPredicate();
-          Pred = ICI.getSwappedPredicate(Pred);
-          return new ICmpInst(Pred, LHSI->getOperand(0),
-                              Builder->getInt(*RHSV ^ NotSignBit));
-        }
+    if (LHSI->hasOneUse()) {
+      // (icmp u/s (xor A SignBit), C) -> (icmp s/u A, (xor C SignBit))
+      if (!ICI.isEquality() && XorCst->getValue().isSignBit()) {
+        const APInt &SignBit = XorCst->getValue();
+        ICmpInst::Predicate Pred = ICI.isSigned() ? ICI.getUnsignedPredicate()
+                                                  : ICI.getSignedPredicate();
+        return new ICmpInst(Pred, LHSI->getOperand(0),
+                            Builder->getInt(*RHSV ^ SignBit));
       }
 
-      // (icmp ugt (xor X, C), ~C) -> (icmp ult X, C)
-      //   iff -C is a power of 2
-      if (ICI.getPredicate() == ICmpInst::ICMP_UGT &&
-          XorCst->getValue() == ~(*RHSV) && (*RHSV + 1).isPowerOf2())
-        return new ICmpInst(ICmpInst::ICMP_ULT, LHSI->getOperand(0), XorCst);
-
-      // (icmp ult (xor X, C), -C) -> (icmp uge X, C)
-      //   iff -C is a power of 2
-      if (ICI.getPredicate() == ICmpInst::ICMP_ULT &&
-          XorCst->getValue() == -(*RHSV) && RHSV->isPowerOf2())
-        return new ICmpInst(ICmpInst::ICMP_UGE, LHSI->getOperand(0), XorCst);
+      // (icmp u/s (xor A ~SignBit), C) -> (icmp s/u (xor C ~SignBit), A)
+      if (!ICI.isEquality() && XorCst->isMaxValue(true)) {
+        const APInt &NotSignBit = XorCst->getValue();
+        ICmpInst::Predicate Pred = ICI.isSigned() ? ICI.getUnsignedPredicate()
+                                                  : ICI.getSignedPredicate();
+        Pred = ICI.getSwappedPredicate(Pred);
+        return new ICmpInst(Pred, LHSI->getOperand(0),
+                            Builder->getInt(*RHSV ^ NotSignBit));
+      }
     }
-    break;
-  case Instruction::And:         // (icmp pred (and X, AndCst), RHS)
-    if (LHSI->hasOneUse() && isa<ConstantInt>(LHSI->getOperand(1)) &&
-        LHSI->getOperand(0)->hasOneUse()) {
-      ConstantInt *AndCst = cast<ConstantInt>(LHSI->getOperand(1));
-
-      // If the LHS is an AND of a truncating cast, we can widen the
-      // and/compare to be the input width without changing the value
-      // produced, eliminating a cast.
-      if (TruncInst *Cast = dyn_cast<TruncInst>(LHSI->getOperand(0))) {
-        // We can do this transformation if either the AND constant does not
-        // have its sign bit set or if it is an equality comparison.
-        // Extending a relational comparison when we're checking the sign
-        // bit would not work.
-        if (ICI.isEquality() ||
-            (!AndCst->isNegative() && RHSV->isNonNegative())) {
-          Value *NewAnd =
+
+    // (icmp ugt (xor X, C), ~C) -> (icmp ult X, C)
+    //   iff -C is a power of 2
+    if (ICI.getPredicate() == ICmpInst::ICMP_UGT &&
+        XorCst->getValue() == ~(*RHSV) && (*RHSV + 1).isPowerOf2())
+      return new ICmpInst(ICmpInst::ICMP_ULT, LHSI->getOperand(0), XorCst);
+
+    // (icmp ult (xor X, C), -C) -> (icmp uge X, C)
+    //   iff -C is a power of 2
+    if (ICI.getPredicate() == ICmpInst::ICMP_ULT &&
+        XorCst->getValue() == -(*RHSV) && RHSV->isPowerOf2())
+      return new ICmpInst(ICmpInst::ICMP_UGE, LHSI->getOperand(0), XorCst);
+  }
+  return nullptr;
+}
+
+Instruction *InstCombiner::foldICmpAndConstant(ICmpInst &ICI, Instruction *LHSI,
+                                               const APInt *RHSV) {
+  // FIXME: This check restricts all folds under here to scalar types.
+  ConstantInt *RHS = dyn_cast<ConstantInt>(ICI.getOperand(1));
+  if (!RHS)
+    return nullptr;
+
+  if (LHSI->hasOneUse() && isa<ConstantInt>(LHSI->getOperand(1)) &&
+      LHSI->getOperand(0)->hasOneUse()) {
+    ConstantInt *AndCst = cast<ConstantInt>(LHSI->getOperand(1));
+
+    // If the LHS is an AND of a truncating cast, we can widen the
+    // and/compare to be the input width without changing the value
+    // produced, eliminating a cast.
+    if (TruncInst *Cast = dyn_cast<TruncInst>(LHSI->getOperand(0))) {
+      // We can do this transformation if either the AND constant does not
+      // have its sign bit set or if it is an equality comparison.
+      // Extending a relational comparison when we're checking the sign
+      // bit would not work.
+      if (ICI.isEquality() ||
+          (!AndCst->isNegative() && RHSV->isNonNegative())) {
+        Value *NewAnd =
             Builder->CreateAnd(Cast->getOperand(0),
                                ConstantExpr::getZExt(AndCst, Cast->getSrcTy()));
-          NewAnd->takeName(LHSI);
-          return new ICmpInst(ICI.getPredicate(), NewAnd,
-                              ConstantExpr::getZExt(RHS, Cast->getSrcTy()));
-        }
+        NewAnd->takeName(LHSI);
+        return new ICmpInst(ICI.getPredicate(), NewAnd,
+                            ConstantExpr::getZExt(RHS, Cast->getSrcTy()));
       }
+    }
 
-      // If the LHS is an AND of a zext, and we have an equality compare, we can
-      // shrink the and/compare to the smaller type, eliminating the cast.
-      if (ZExtInst *Cast = dyn_cast<ZExtInst>(LHSI->getOperand(0))) {
-        IntegerType *Ty = cast<IntegerType>(Cast->getSrcTy());
-        // Make sure we don't compare the upper bits, SimplifyDemandedBits
-        // should fold the icmp to true/false in that case.
-        if (ICI.isEquality() && RHSV->getActiveBits() <= Ty->getBitWidth()) {
-          Value *NewAnd =
-            Builder->CreateAnd(Cast->getOperand(0),
-                               ConstantExpr::getTrunc(AndCst, Ty));
-          NewAnd->takeName(LHSI);
-          return new ICmpInst(ICI.getPredicate(), NewAnd,
-                              ConstantExpr::getTrunc(RHS, Ty));
-        }
+    // If the LHS is an AND of a zext, and we have an equality compare, we can
+    // shrink the and/compare to the smaller type, eliminating the cast.
+    if (ZExtInst *Cast = dyn_cast<ZExtInst>(LHSI->getOperand(0))) {
+      IntegerType *Ty = cast<IntegerType>(Cast->getSrcTy());
+      // Make sure we don't compare the upper bits, SimplifyDemandedBits
+      // should fold the icmp to true/false in that case.
+      if (ICI.isEquality() && RHSV->getActiveBits() <= Ty->getBitWidth()) {
+        Value *NewAnd = Builder->CreateAnd(Cast->getOperand(0),
+                                           ConstantExpr::getTrunc(AndCst, Ty));
+        NewAnd->takeName(LHSI);
+        return new ICmpInst(ICI.getPredicate(), NewAnd,
+                            ConstantExpr::getTrunc(RHS, Ty));
       }
+    }
 
-      // If this is: (X >> C1) & C2 != C3 (where any shift and any compare
-      // could exist), turn it into (X & (C2 << C1)) != (C3 << C1).  This
-      // happens a LOT in code produced by the C front-end, for bitfield
-      // access.
-      BinaryOperator *Shift = dyn_cast<BinaryOperator>(LHSI->getOperand(0));
-      if (Shift && !Shift->isShift())
-        Shift = nullptr;
-
-      ConstantInt *ShAmt;
-      ShAmt = Shift ? dyn_cast<ConstantInt>(Shift->getOperand(1)) : nullptr;
-
-      // This seemingly simple opportunity to fold away a shift turns out to
-      // be rather complicated. See PR17827
-      // ( http://llvm.org/bugs/show_bug.cgi?id=17827 ) for details.
-      if (ShAmt) {
-        bool CanFold = false;
-        unsigned ShiftOpcode = Shift->getOpcode();
-        if (ShiftOpcode == Instruction::AShr) {
-          // There may be some constraints that make this possible,
-          // but nothing simple has been discovered yet.
-          CanFold = false;
-        } else if (ShiftOpcode == Instruction::Shl) {
-          // For a left shift, we can fold if the comparison is not signed.
-          // We can also fold a signed comparison if the mask value and
-          // comparison value are not negative. These constraints may not be
-          // obvious, but we can prove that they are correct using an SMT
-          // solver.
-          if (!ICI.isSigned() || (!AndCst->isNegative() && !RHS->isNegative()))
-            CanFold = true;
-        } else if (ShiftOpcode == Instruction::LShr) {
-          // For a logical right shift, we can fold if the comparison is not
-          // signed. We can also fold a signed comparison if the shifted mask
-          // value and the shifted comparison value are not negative.
-          // These constraints may not be obvious, but we can prove that they
-          // are correct using an SMT solver.
-          if (!ICI.isSigned())
-            CanFold = true;
-          else {
-            ConstantInt *ShiftedAndCst =
+    // If this is: (X >> C1) & C2 != C3 (where any shift and any compare
+    // could exist), turn it into (X & (C2 << C1)) != (C3 << C1).  This
+    // happens a LOT in code produced by the C front-end, for bitfield
+    // access.
+    BinaryOperator *Shift = dyn_cast<BinaryOperator>(LHSI->getOperand(0));
+    if (Shift && !Shift->isShift())
+      Shift = nullptr;
+
+    ConstantInt *ShAmt;
+    ShAmt = Shift ? dyn_cast<ConstantInt>(Shift->getOperand(1)) : nullptr;
+
+    // This seemingly simple opportunity to fold away a shift turns out to
+    // be rather complicated. See PR17827
+    // ( http://llvm.org/bugs/show_bug.cgi?id=17827 ) for details.
+    if (ShAmt) {
+      bool CanFold = false;
+      unsigned ShiftOpcode = Shift->getOpcode();
+      if (ShiftOpcode == Instruction::AShr) {
+        // There may be some constraints that make this possible,
+        // but nothing simple has been discovered yet.
+        CanFold = false;
+      } else if (ShiftOpcode == Instruction::Shl) {
+        // For a left shift, we can fold if the comparison is not signed.
+        // We can also fold a signed comparison if the mask value and
+        // comparison value are not negative. These constraints may not be
+        // obvious, but we can prove that they are correct using an SMT
+        // solver.
+        if (!ICI.isSigned() || (!AndCst->isNegative() && !RHS->isNegative()))
+          CanFold = true;
+      } else if (ShiftOpcode == Instruction::LShr) {
+        // For a logical right shift, we can fold if the comparison is not
+        // signed. We can also fold a signed comparison if the shifted mask
+        // value and the shifted comparison value are not negative.
+        // These constraints may not be obvious, but we can prove that they
+        // are correct using an SMT solver.
+        if (!ICI.isSigned())
+          CanFold = true;
+        else {
+          ConstantInt *ShiftedAndCst =
               cast<ConstantInt>(ConstantExpr::getShl(AndCst, ShAmt));
-            ConstantInt *ShiftedRHSCst =
+          ConstantInt *ShiftedRHSCst =
               cast<ConstantInt>(ConstantExpr::getShl(RHS, ShAmt));
 
-            if (!ShiftedAndCst->isNegative() && !ShiftedRHSCst->isNegative())
-              CanFold = true;
-          }
+          if (!ShiftedAndCst->isNegative() && !ShiftedRHSCst->isNegative())
+            CanFold = true;
         }
+      }
+
+      if (CanFold) {
+        Constant *NewCst;
+        if (ShiftOpcode == Instruction::Shl)
+          NewCst = ConstantExpr::getLShr(RHS, ShAmt);
+        else
+          NewCst = ConstantExpr::getShl(RHS, ShAmt);
 
-        if (CanFold) {
-          Constant *NewCst;
+        // Check to see if we are shifting out any of the bits being
+        // compared.
+        if (ConstantExpr::get(ShiftOpcode, NewCst, ShAmt) != RHS) {
+          // If we shifted bits out, the fold is not going to work out.
+          // As a special case, check to see if this means that the
+          // result is always true or false now.
+          if (ICI.getPredicate() == ICmpInst::ICMP_EQ)
+            return replaceInstUsesWith(ICI, Builder->getFalse());
+          if (ICI.getPredicate() == ICmpInst::ICMP_NE)
+            return replaceInstUsesWith(ICI, Builder->getTrue());
+        } else {
+          ICI.setOperand(1, NewCst);
+          Constant *NewAndCst;
           if (ShiftOpcode == Instruction::Shl)
-            NewCst = ConstantExpr::getLShr(RHS, ShAmt);
+            NewAndCst = ConstantExpr::getLShr(AndCst, ShAmt);
           else
-            NewCst = ConstantExpr::getShl(RHS, ShAmt);
-
-          // Check to see if we are shifting out any of the bits being
-          // compared.
-          if (ConstantExpr::get(ShiftOpcode, NewCst, ShAmt) != RHS) {
-            // If we shifted bits out, the fold is not going to work out.
-            // As a special case, check to see if this means that the
-            // result is always true or false now.
-            if (ICI.getPredicate() == ICmpInst::ICMP_EQ)
-              return replaceInstUsesWith(ICI, Builder->getFalse());
-            if (ICI.getPredicate() == ICmpInst::ICMP_NE)
-              return replaceInstUsesWith(ICI, Builder->getTrue());
-          } else {
-            ICI.setOperand(1, NewCst);
-            Constant *NewAndCst;
-            if (ShiftOpcode == Instruction::Shl)
-              NewAndCst = ConstantExpr::getLShr(AndCst, ShAmt);
-            else
-              NewAndCst = ConstantExpr::getShl(AndCst, ShAmt);
-            LHSI->setOperand(1, NewAndCst);
-            LHSI->setOperand(0, Shift->getOperand(0));
-            Worklist.Add(Shift); // Shift is dead.
-            return &ICI;
-          }
+            NewAndCst = ConstantExpr::getShl(AndCst, ShAmt);
+          LHSI->setOperand(1, NewAndCst);
+          LHSI->setOperand(0, Shift->getOperand(0));
+          Worklist.Add(Shift); // Shift is dead.
+          return &ICI;
         }
       }
+    }
 
-      // Turn ((X >> Y) & C) == 0  into  (X & (C << Y)) == 0.  The later is
-      // preferable because it allows the C<<Y expression to be hoisted out
-      // of a loop if Y is invariant and X is not.
-      if (Shift && Shift->hasOneUse() && *RHSV == 0 &&
-          ICI.isEquality() && !Shift->isArithmeticShift() &&
-          !isa<Constant>(Shift->getOperand(0))) {
-        // Compute C << Y.
-        Value *NS;
-        if (Shift->getOpcode() == Instruction::LShr) {
-          NS = Builder->CreateShl(AndCst, Shift->getOperand(1));
-        } else {
-          // Insert a logical shift.
-          NS = Builder->CreateLShr(AndCst, Shift->getOperand(1));
-        }
+    // Turn ((X >> Y) & C) == 0  into  (X & (C << Y)) == 0.  The later is
+    // preferable because it allows the C<<Y expression to be hoisted out
+    // of a loop if Y is invariant and X is not.
+    if (Shift && Shift->hasOneUse() && *RHSV == 0 && ICI.isEquality() &&
+        !Shift->isArithmeticShift() && !isa<Constant>(Shift->getOperand(0))) {
+      // Compute C << Y.
+      Value *NS;
+      if (Shift->getOpcode() == Instruction::LShr) {
+        NS = Builder->CreateShl(AndCst, Shift->getOperand(1));
+      } else {
+        // Insert a logical shift.
+        NS = Builder->CreateLShr(AndCst, Shift->getOperand(1));
+      }
 
-        // Compute X & (C << Y).
-        Value *NewAnd =
+      // Compute X & (C << Y).
+      Value *NewAnd =
           Builder->CreateAnd(Shift->getOperand(0), NS, LHSI->getName());
 
-        ICI.setOperand(0, NewAnd);
-        return &ICI;
-      }
+      ICI.setOperand(0, NewAnd);
+      return &ICI;
+    }
 
-      // (icmp pred (and (or (lshr X, Y), X), 1), 0) -->
-      //    (icmp pred (and X, (or (shl 1, Y), 1), 0))
-      //
-      // iff pred isn't signed
-      {
-        Value *X, *Y, *LShr;
-        if (!ICI.isSigned() && *RHSV == 0) {
-          if (match(LHSI->getOperand(1), m_One())) {
-            Constant *One = cast<Constant>(LHSI->getOperand(1));
-            Value *Or = LHSI->getOperand(0);
-            if (match(Or, m_Or(m_Value(LShr), m_Value(X))) &&
-                match(LShr, m_LShr(m_Specific(X), m_Value(Y)))) {
-              unsigned UsesRemoved = 0;
-              if (LHSI->hasOneUse())
-                ++UsesRemoved;
-              if (Or->hasOneUse())
-                ++UsesRemoved;
-              if (LShr->hasOneUse())
-                ++UsesRemoved;
-              Value *NewOr = nullptr;
-              // Compute X & ((1 << Y) | 1)
-              if (auto *C = dyn_cast<Constant>(Y)) {
-                if (UsesRemoved >= 1)
-                  NewOr =
-                      ConstantExpr::getOr(ConstantExpr::getNUWShl(One, C), One);
-              } else {
-                if (UsesRemoved >= 3)
-                  NewOr = Builder->CreateOr(Builder->CreateShl(One, Y,
-                                                               LShr->getName(),
-                                                               /*HasNUW=*/true),
-                                            One, Or->getName());
-              }
-              if (NewOr) {
-                Value *NewAnd = Builder->CreateAnd(X, NewOr, LHSI->getName());
-                ICI.setOperand(0, NewAnd);
-                return &ICI;
-              }
+    // (icmp pred (and (or (lshr X, Y), X), 1), 0) -->
+    //    (icmp pred (and X, (or (shl 1, Y), 1), 0))
+    //
+    // iff pred isn't signed
+    {
+      Value *X, *Y, *LShr;
+      if (!ICI.isSigned() && *RHSV == 0) {
+        if (match(LHSI->getOperand(1), m_One())) {
+          Constant *One = cast<Constant>(LHSI->getOperand(1));
+          Value *Or = LHSI->getOperand(0);
+          if (match(Or, m_Or(m_Value(LShr), m_Value(X))) &&
+              match(LShr, m_LShr(m_Specific(X), m_Value(Y)))) {
+            unsigned UsesRemoved = 0;
+            if (LHSI->hasOneUse())
+              ++UsesRemoved;
+            if (Or->hasOneUse())
+              ++UsesRemoved;
+            if (LShr->hasOneUse())
+              ++UsesRemoved;
+            Value *NewOr = nullptr;
+            // Compute X & ((1 << Y) | 1)
+            if (auto *C = dyn_cast<Constant>(Y)) {
+              if (UsesRemoved >= 1)
+                NewOr =
+                    ConstantExpr::getOr(ConstantExpr::getNUWShl(One, C), One);
+            } else {
+              if (UsesRemoved >= 3)
+                NewOr = Builder->CreateOr(Builder->CreateShl(One, Y,
+                                                             LShr->getName(),
+                                                             /*HasNUW=*/true),
+                                          One, Or->getName());
+            }
+            if (NewOr) {
+              Value *NewAnd = Builder->CreateAnd(X, NewOr, LHSI->getName());
+              ICI.setOperand(0, NewAnd);
+              return &ICI;
             }
           }
         }
       }
-
-      // Replace ((X & AndCst) > RHSV) with ((X & AndCst) != 0), if any
-      // bit set in (X & AndCst) will produce a result greater than RHSV.
-      if (ICI.getPredicate() == ICmpInst::ICMP_UGT) {
-        unsigned NTZ = AndCst->getValue().countTrailingZeros();
-        if ((NTZ < AndCst->getBitWidth()) &&
-            APInt::getOneBitSet(AndCst->getBitWidth(), NTZ).ugt(*RHSV))
-          return new ICmpInst(ICmpInst::ICMP_NE, LHSI,
-                              Constant::getNullValue(RHS->getType()));
-      }
     }
 
-    // Try to optimize things like "A[i]&42 == 0" to index computations.
-    if (LoadInst *LI = dyn_cast<LoadInst>(LHSI->getOperand(0))) {
-      if (GetElementPtrInst *GEP =
-          dyn_cast<GetElementPtrInst>(LI->getOperand(0)))
-        if (GlobalVariable *GV = dyn_cast<GlobalVariable>(GEP->getOperand(0)))
-          if (GV->isConstant() && GV->hasDefinitiveInitializer() &&
-              !LI->isVolatile() && isa<ConstantInt>(LHSI->getOperand(1))) {
-            ConstantInt *C = cast<ConstantInt>(LHSI->getOperand(1));
-            if (Instruction *Res = foldCmpLoadFromIndexedGlobal(GEP, GV,ICI, C))
-              return Res;
-          }
+    // Replace ((X & AndCst) > RHSV) with ((X & AndCst) != 0), if any
+    // bit set in (X & AndCst) will produce a result greater than RHSV.
+    if (ICI.getPredicate() == ICmpInst::ICMP_UGT) {
+      unsigned NTZ = AndCst->getValue().countTrailingZeros();
+      if ((NTZ < AndCst->getBitWidth()) &&
+          APInt::getOneBitSet(AndCst->getBitWidth(), NTZ).ugt(*RHSV))
+        return new ICmpInst(ICmpInst::ICMP_NE, LHSI,
+                            Constant::getNullValue(RHS->getType()));
     }
+  }
 
-    // X & -C == -C -> X >  u ~C
-    // X & -C != -C -> X <= u ~C
-    //   iff C is a power of 2
-    if (ICI.isEquality() && RHS == LHSI->getOperand(1) && (-(*RHSV)).isPowerOf2())
-      return new ICmpInst(
-          ICI.getPredicate() == ICmpInst::ICMP_EQ ? ICmpInst::ICMP_UGT
-                                                  : ICmpInst::ICMP_ULE,
-          LHSI->getOperand(0), SubOne(RHS));
-
-    // (icmp eq (and %A, C), 0) -> (icmp sgt (trunc %A), -1)
-    //   iff C is a power of 2
-    if (ICI.isEquality() && LHSI->hasOneUse() && match(RHS, m_Zero())) {
-      if (auto *CI = dyn_cast<ConstantInt>(LHSI->getOperand(1))) {
-        const APInt &AI = CI->getValue();
-        int32_t ExactLogBase2 = AI.exactLogBase2();
-        if (ExactLogBase2 != -1 && DL.isLegalInteger(ExactLogBase2 + 1)) {
-          Type *NTy = IntegerType::get(ICI.getContext(), ExactLogBase2 + 1);
-          Value *Trunc = Builder->CreateTrunc(LHSI->getOperand(0), NTy);
-          return new ICmpInst(ICI.getPredicate() == ICmpInst::ICMP_EQ
-                                  ? ICmpInst::ICMP_SGE
-                                  : ICmpInst::ICMP_SLT,
-                              Trunc, Constant::getNullValue(NTy));
+  // Try to optimize things like "A[i]&42 == 0" to index computations.
+  if (LoadInst *LI = dyn_cast<LoadInst>(LHSI->getOperand(0))) {
+    if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(LI->getOperand(0)))
+      if (GlobalVariable *GV = dyn_cast<GlobalVariable>(GEP->getOperand(0)))
+        if (GV->isConstant() && GV->hasDefinitiveInitializer() &&
+            !LI->isVolatile() && isa<ConstantInt>(LHSI->getOperand(1))) {
+          ConstantInt *C = cast<ConstantInt>(LHSI->getOperand(1));
+          if (Instruction *Res = foldCmpLoadFromIndexedGlobal(GEP, GV, ICI, C))
+            return Res;
         }
+  }
+
+  // X & -C == -C -> X >  u ~C
+  // X & -C != -C -> X <= u ~C
+  //   iff C is a power of 2
+  if (ICI.isEquality() && RHS == LHSI->getOperand(1) && (-(*RHSV)).isPowerOf2())
+    return new ICmpInst(ICI.getPredicate() == ICmpInst::ICMP_EQ
+                            ? ICmpInst::ICMP_UGT
+                            : ICmpInst::ICMP_ULE,
+                        LHSI->getOperand(0), SubOne(RHS));
+
+  // (icmp eq (and %A, C), 0) -> (icmp sgt (trunc %A), -1)
+  //   iff C is a power of 2
+  if (ICI.isEquality() && LHSI->hasOneUse() && match(RHS, m_Zero())) {
+    if (auto *CI = dyn_cast<ConstantInt>(LHSI->getOperand(1))) {
+      const APInt &AI = CI->getValue();
+      int32_t ExactLogBase2 = AI.exactLogBase2();
+      if (ExactLogBase2 != -1 && DL.isLegalInteger(ExactLogBase2 + 1)) {
+        Type *NTy = IntegerType::get(ICI.getContext(), ExactLogBase2 + 1);
+        Value *Trunc = Builder->CreateTrunc(LHSI->getOperand(0), NTy);
+        return new ICmpInst(ICI.getPredicate() == ICmpInst::ICMP_EQ
+                                ? ICmpInst::ICMP_SGE
+                                : ICmpInst::ICMP_SLT,
+                            Trunc, Constant::getNullValue(NTy));
       }
     }
-    break;
+  }
+  return nullptr;
+}
 
-  case Instruction::Or: {
-    if (RHS->isOne()) {
-      // icmp slt signum(V) 1 --> icmp slt V, 1
-      Value *V = nullptr;
-      if (ICI.getPredicate() == ICmpInst::ICMP_SLT &&
-          match(LHSI, m_Signum(m_Value(V))))
-        return new ICmpInst(ICmpInst::ICMP_SLT, V,
-                            ConstantInt::get(V->getType(), 1));
-    }
-
-    if (!ICI.isEquality() || !RHS->isNullValue() || !LHSI->hasOneUse())
-      break;
-    Value *P, *Q;
-    if (match(LHSI, m_Or(m_PtrToInt(m_Value(P)), m_PtrToInt(m_Value(Q))))) {
-      // Simplify icmp eq (or (ptrtoint P), (ptrtoint Q)), 0
-      // -> and (icmp eq P, null), (icmp eq Q, null).
-      Value *ICIP = Builder->CreateICmp(ICI.getPredicate(), P,
-                                        Constant::getNullValue(P->getType()));
-      Value *ICIQ = Builder->CreateICmp(ICI.getPredicate(), Q,
-                                        Constant::getNullValue(Q->getType()));
-      Instruction *Op;
-      if (ICI.getPredicate() == ICmpInst::ICMP_EQ)
-        Op = BinaryOperator::CreateAnd(ICIP, ICIQ);
-      else
-        Op = BinaryOperator::CreateOr(ICIP, ICIQ);
-      return Op;
-    }
-    break;
+Instruction *InstCombiner::foldICmpOrConstant(ICmpInst &ICI, Instruction *LHSI,
+                                              const APInt *RHSV) {
+  // FIXME: This check restricts all folds under here to scalar types.
+  ConstantInt *RHS = dyn_cast<ConstantInt>(ICI.getOperand(1));
+  if (!RHS)
+    return nullptr;
+
+  if (RHS->isOne()) {
+    // icmp slt signum(V) 1 --> icmp slt V, 1
+    Value *V = nullptr;
+    if (ICI.getPredicate() == ICmpInst::ICMP_SLT &&
+        match(LHSI, m_Signum(m_Value(V))))
+      return new ICmpInst(ICmpInst::ICMP_SLT, V,
+                          ConstantInt::get(V->getType(), 1));
   }
 
-  case Instruction::Mul: {       // (icmp pred (mul X, Val), CI)
-    ConstantInt *Val = dyn_cast<ConstantInt>(LHSI->getOperand(1));
-    if (!Val) break;
-
-    // If this is a signed comparison to 0 and the mul is sign preserving,
-    // use the mul LHS operand instead.
-    ICmpInst::Predicate pred = ICI.getPredicate();
-    if (isSignTest(pred, RHS) && !Val->isZero() &&
-        cast<BinaryOperator>(LHSI)->hasNoSignedWrap())
-      return new ICmpInst(Val->isNegative() ?
-                          ICmpInst::getSwappedPredicate(pred) : pred,
-                          LHSI->getOperand(0),
-                          Constant::getNullValue(RHS->getType()));
+  if (!ICI.isEquality() || !RHS->isNullValue() || !LHSI->hasOneUse())
+    return nullptr;
 
-    break;
+  Value *P, *Q;
+  if (match(LHSI, m_Or(m_PtrToInt(m_Value(P)), m_PtrToInt(m_Value(Q))))) {
+    // Simplify icmp eq (or (ptrtoint P), (ptrtoint Q)), 0
+    // -> and (icmp eq P, null), (icmp eq Q, null).
+    Value *ICIP = Builder->CreateICmp(ICI.getPredicate(), P,
+                                      Constant::getNullValue(P->getType()));
+    Value *ICIQ = Builder->CreateICmp(ICI.getPredicate(), Q,
+                                      Constant::getNullValue(Q->getType()));
+    Instruction *Op;
+    if (ICI.getPredicate() == ICmpInst::ICMP_EQ)
+      Op = BinaryOperator::CreateAnd(ICIP, ICIQ);
+    else
+      Op = BinaryOperator::CreateOr(ICIP, ICIQ);
+    return Op;
   }
+  return nullptr;
+}
 
-  case Instruction::Shl: {       // (icmp pred (shl X, ShAmt), CI)
-    uint32_t TypeBits = RHSV->getBitWidth();
-    ConstantInt *ShAmt = dyn_cast<ConstantInt>(LHSI->getOperand(1));
-    if (!ShAmt) {
-      Value *X;
-      // (1 << X) pred P2 -> X pred Log2(P2)
-      if (match(LHSI, m_Shl(m_One(), m_Value(X)))) {
-        bool RHSVIsPowerOf2 = RHSV->isPowerOf2();
-        ICmpInst::Predicate Pred = ICI.getPredicate();
-        if (ICI.isUnsigned()) {
-          if (!RHSVIsPowerOf2) {
-            // (1 << X) <  30 -> X <= 4
-            // (1 << X) <= 30 -> X <= 4
-            // (1 << X) >= 30 -> X >  4
-            // (1 << X) >  30 -> X >  4
-            if (Pred == ICmpInst::ICMP_ULT)
-              Pred = ICmpInst::ICMP_ULE;
-            else if (Pred == ICmpInst::ICMP_UGE)
-              Pred = ICmpInst::ICMP_UGT;
-          }
-          unsigned RHSLog2 = RHSV->logBase2();
+Instruction *InstCombiner::foldICmpMulConstant(ICmpInst &ICI, Instruction *LHSI,
+                                               const APInt *RHSV) {
+  // FIXME: This check restricts all folds under here to scalar types.
+  ConstantInt *RHS = dyn_cast<ConstantInt>(ICI.getOperand(1));
+  if (!RHS)
+    return nullptr;
 
-          // (1 << X) >= 2147483648 -> X >= 31 -> X == 31
-          // (1 << X) <  2147483648 -> X <  31 -> X != 31
-          if (RHSLog2 == TypeBits-1) {
-            if (Pred == ICmpInst::ICMP_UGE)
-              Pred = ICmpInst::ICMP_EQ;
-            else if (Pred == ICmpInst::ICMP_ULT)
-              Pred = ICmpInst::ICMP_NE;
-          }
+  ConstantInt *Val = dyn_cast<ConstantInt>(LHSI->getOperand(1));
+  if (!Val)
+    return nullptr;
 
-          return new ICmpInst(Pred, X,
-                              ConstantInt::get(RHS->getType(), RHSLog2));
-        } else if (ICI.isSigned()) {
-          if (RHSV->isAllOnesValue()) {
-            // (1 << X) <= -1 -> X == 31
-            if (Pred == ICmpInst::ICMP_SLE)
-              return new ICmpInst(ICmpInst::ICMP_EQ, X,
-                                  ConstantInt::get(RHS->getType(), TypeBits-1));
-
-            // (1 << X) >  -1 -> X != 31
-            if (Pred == ICmpInst::ICMP_SGT)
-              return new ICmpInst(ICmpInst::ICMP_NE, X,
-                                  ConstantInt::get(RHS->getType(), TypeBits-1));
-          } else if (!(*RHSV)) {
-            // (1 << X) <  0 -> X == 31
-            // (1 << X) <= 0 -> X == 31
-            if (Pred == ICmpInst::ICMP_SLT || Pred == ICmpInst::ICMP_SLE)
-              return new ICmpInst(ICmpInst::ICMP_EQ, X,
-                                  ConstantInt::get(RHS->getType(), TypeBits-1));
-
-            // (1 << X) >= 0 -> X != 31
-            // (1 << X) >  0 -> X != 31
-            if (Pred == ICmpInst::ICMP_SGT || Pred == ICmpInst::ICMP_SGE)
-              return new ICmpInst(ICmpInst::ICMP_NE, X,
-                                  ConstantInt::get(RHS->getType(), TypeBits-1));
-          }
-        } else if (ICI.isEquality()) {
-          if (RHSVIsPowerOf2)
-            return new ICmpInst(
-                Pred, X, ConstantInt::get(RHS->getType(), RHSV->logBase2()));
+  // If this is a signed comparison to 0 and the mul is sign preserving,
+  // use the mul LHS operand instead.
+  ICmpInst::Predicate pred = ICI.getPredicate();
+  if (isSignTest(pred, RHS) && !Val->isZero() &&
+      cast<BinaryOperator>(LHSI)->hasNoSignedWrap())
+    return new ICmpInst(Val->isNegative() ?
+                        ICmpInst::getSwappedPredicate(pred) : pred,
+                        LHSI->getOperand(0),
+                        Constant::getNullValue(RHS->getType()));
+
+  return nullptr;
+}
+
+Instruction *InstCombiner::foldICmpShlConstant(ICmpInst &ICI, Instruction *LHSI,
+                                               const APInt *RHSV) {
+  // FIXME: This check restricts all folds under here to scalar types.
+  ConstantInt *RHS = dyn_cast<ConstantInt>(ICI.getOperand(1));
+  if (!RHS)
+    return nullptr;
+
+  uint32_t TypeBits = RHSV->getBitWidth();
+  ConstantInt *ShAmt = dyn_cast<ConstantInt>(LHSI->getOperand(1));
+  if (!ShAmt) {
+    Value *X;
+    // (1 << X) pred P2 -> X pred Log2(P2)
+    if (match(LHSI, m_Shl(m_One(), m_Value(X)))) {
+      bool RHSVIsPowerOf2 = RHSV->isPowerOf2();
+      ICmpInst::Predicate Pred = ICI.getPredicate();
+      if (ICI.isUnsigned()) {
+        if (!RHSVIsPowerOf2) {
+          // (1 << X) <  30 -> X <= 4
+          // (1 << X) <= 30 -> X <= 4
+          // (1 << X) >= 30 -> X >  4
+          // (1 << X) >  30 -> X >  4
+          if (Pred == ICmpInst::ICMP_ULT)
+            Pred = ICmpInst::ICMP_ULE;
+          else if (Pred == ICmpInst::ICMP_UGE)
+            Pred = ICmpInst::ICMP_UGT;
         }
+        unsigned RHSLog2 = RHSV->logBase2();
+
+        // (1 << X) >= 2147483648 -> X >= 31 -> X == 31
+        // (1 << X) <  2147483648 -> X <  31 -> X != 31
+        if (RHSLog2 == TypeBits - 1) {
+          if (Pred == ICmpInst::ICMP_UGE)
+            Pred = ICmpInst::ICMP_EQ;
+          else if (Pred == ICmpInst::ICMP_ULT)
+            Pred = ICmpInst::ICMP_NE;
+        }
+
+        return new ICmpInst(Pred, X, ConstantInt::get(RHS->getType(), RHSLog2));
+      } else if (ICI.isSigned()) {
+        if (RHSV->isAllOnesValue()) {
+          // (1 << X) <= -1 -> X == 31
+          if (Pred == ICmpInst::ICMP_SLE)
+            return new ICmpInst(ICmpInst::ICMP_EQ, X,
+                                ConstantInt::get(RHS->getType(), TypeBits - 1));
+
+          // (1 << X) >  -1 -> X != 31
+          if (Pred == ICmpInst::ICMP_SGT)
+            return new ICmpInst(ICmpInst::ICMP_NE, X,
+                                ConstantInt::get(RHS->getType(), TypeBits - 1));
+        } else if (!(*RHSV)) {
+          // (1 << X) <  0 -> X == 31
+          // (1 << X) <= 0 -> X == 31
+          if (Pred == ICmpInst::ICMP_SLT || Pred == ICmpInst::ICMP_SLE)
+            return new ICmpInst(ICmpInst::ICMP_EQ, X,
+                                ConstantInt::get(RHS->getType(), TypeBits - 1));
+
+          // (1 << X) >= 0 -> X != 31
+          // (1 << X) >  0 -> X != 31
+          if (Pred == ICmpInst::ICMP_SGT || Pred == ICmpInst::ICMP_SGE)
+            return new ICmpInst(ICmpInst::ICMP_NE, X,
+                                ConstantInt::get(RHS->getType(), TypeBits - 1));
+        }
+      } else if (ICI.isEquality()) {
+        if (RHSVIsPowerOf2)
+          return new ICmpInst(
+              Pred, X, ConstantInt::get(RHS->getType(), RHSV->logBase2()));
       }
-      break;
     }
+    return nullptr;
+  }
+
+  // Check that the shift amount is in range.  If not, don't perform
+  // undefined shifts.  When the shift is visited it will be
+  // simplified.
+  if (ShAmt->uge(TypeBits))
+    return nullptr;
 
-    // Check that the shift amount is in range.  If not, don't perform
-    // undefined shifts.  When the shift is visited it will be
-    // simplified.
-    if (ShAmt->uge(TypeBits))
-      break;
-
-    if (ICI.isEquality()) {
-      // If we are comparing against bits always shifted out, the
-      // comparison cannot succeed.
-      Constant *Comp =
-        ConstantExpr::getShl(ConstantExpr::getLShr(RHS, ShAmt),
-                                                                 ShAmt);
-      if (Comp != RHS) {// Comparing against a bit that we know is zero.
-        bool IsICMP_NE = ICI.getPredicate() == ICmpInst::ICMP_NE;
-        Constant *Cst = Builder->getInt1(IsICMP_NE);
-        return replaceInstUsesWith(ICI, Cst);
-      }
-
-      // If the shift is NUW, then it is just shifting out zeros, no need for an
-      // AND.
-      if (cast<BinaryOperator>(LHSI)->hasNoUnsignedWrap())
-        return new ICmpInst(ICI.getPredicate(), LHSI->getOperand(0),
-                            ConstantExpr::getLShr(RHS, ShAmt));
-
-      // If the shift is NSW and we compare to 0, then it is just shifting out
-      // sign bits, no need for an AND either.
-      if (cast<BinaryOperator>(LHSI)->hasNoSignedWrap() && *RHSV == 0)
-        return new ICmpInst(ICI.getPredicate(), LHSI->getOperand(0),
-                            ConstantExpr::getLShr(RHS, ShAmt));
-
-      if (LHSI->hasOneUse()) {
-        // Otherwise strength reduce the shift into an and.
-        uint32_t ShAmtVal = (uint32_t)ShAmt->getLimitedValue(TypeBits);
-        Constant *Mask = Builder->getInt(APInt::getLowBitsSet(TypeBits,
-                                                          TypeBits - ShAmtVal));
-
-        Value *And =
-          Builder->CreateAnd(LHSI->getOperand(0),Mask, LHSI->getName()+".mask");
-        return new ICmpInst(ICI.getPredicate(), And,
-                            ConstantExpr::getLShr(RHS, ShAmt));
-      }
-    }
-
-    // If this is a signed comparison to 0 and the shift is sign preserving,
-    // use the shift LHS operand instead.
-    ICmpInst::Predicate pred = ICI.getPredicate();
-    if (isSignTest(pred, RHS) &&
-        cast<BinaryOperator>(LHSI)->hasNoSignedWrap())
-      return new ICmpInst(pred,
-                          LHSI->getOperand(0),
-                          Constant::getNullValue(RHS->getType()));
-
-    // Otherwise, if this is a comparison of the sign bit, simplify to and/test.
-    bool TrueIfSigned = false;
-    if (LHSI->hasOneUse() &&
-        isSignBitCheck(ICI.getPredicate(), RHS, TrueIfSigned)) {
-      // (X << 31) <s 0  --> (X&1) != 0
-      Constant *Mask = ConstantInt::get(LHSI->getOperand(0)->getType(),
-                                        APInt::getOneBitSet(TypeBits,
-                                            TypeBits-ShAmt->getZExtValue()-1));
-      Value *And =
-        Builder->CreateAnd(LHSI->getOperand(0), Mask, LHSI->getName()+".mask");
-      return new ICmpInst(TrueIfSigned ? ICmpInst::ICMP_NE : ICmpInst::ICMP_EQ,
-                          And, Constant::getNullValue(And->getType()));
-    }
-
-    // Transform (icmp pred iM (shl iM %v, N), CI)
-    // -> (icmp pred i(M-N) (trunc %v iM to i(M-N)), (trunc (CI>>N))
-    // Transform the shl to a trunc if (trunc (CI>>N)) has no loss and M-N.
-    // This enables to get rid of the shift in favor of a trunc which can be
-    // free on the target. It has the additional benefit of comparing to a
-    // smaller constant, which will be target friendly.
-    unsigned Amt = ShAmt->getLimitedValue(TypeBits-1);
-    if (LHSI->hasOneUse() &&
-        Amt != 0 && RHSV->countTrailingZeros() >= Amt) {
-      Type *NTy = IntegerType::get(ICI.getContext(), TypeBits - Amt);
-      Constant *NCI = ConstantExpr::getTrunc(
-                        ConstantExpr::getAShr(RHS,
-                          ConstantInt::get(RHS->getType(), Amt)),
-                        NTy);
-      return new ICmpInst(ICI.getPredicate(),
-                          Builder->CreateTrunc(LHSI->getOperand(0), NTy),
-                          NCI);
+  if (ICI.isEquality()) {
+    // If we are comparing against bits always shifted out, the
+    // comparison cannot succeed.
+    Constant *Comp =
+        ConstantExpr::getShl(ConstantExpr::getLShr(RHS, ShAmt), ShAmt);
+    if (Comp != RHS) { // Comparing against a bit that we know is zero.
+      bool IsICMP_NE = ICI.getPredicate() == ICmpInst::ICMP_NE;
+      Constant *Cst = Builder->getInt1(IsICMP_NE);
+      return replaceInstUsesWith(ICI, Cst);
     }
 
-    break;
+    // If the shift is NUW, then it is just shifting out zeros, no need for an
+    // AND.
+    if (cast<BinaryOperator>(LHSI)->hasNoUnsignedWrap())
+      return new ICmpInst(ICI.getPredicate(), LHSI->getOperand(0),
+                          ConstantExpr::getLShr(RHS, ShAmt));
+
+    // If the shift is NSW and we compare to 0, then it is just shifting out
+    // sign bits, no need for an AND either.
+    if (cast<BinaryOperator>(LHSI)->hasNoSignedWrap() && *RHSV == 0)
+      return new ICmpInst(ICI.getPredicate(), LHSI->getOperand(0),
+                          ConstantExpr::getLShr(RHS, ShAmt));
+
+    if (LHSI->hasOneUse()) {
+      // Otherwise strength reduce the shift into an and.
+      uint32_t ShAmtVal = (uint32_t)ShAmt->getLimitedValue(TypeBits);
+      Constant *Mask =
+          Builder->getInt(APInt::getLowBitsSet(TypeBits, TypeBits - ShAmtVal));
+
+      Value *And = Builder->CreateAnd(LHSI->getOperand(0), Mask,
+                                      LHSI->getName() + ".mask");
+      return new ICmpInst(ICI.getPredicate(), And,
+                          ConstantExpr::getLShr(RHS, ShAmt));
+    }
   }
 
-  case Instruction::LShr:         // (icmp pred (shr X, ShAmt), CI)
-  case Instruction::AShr: {
-    // Handle equality comparisons of shift-by-constant.
-    BinaryOperator *BO = cast<BinaryOperator>(LHSI);
-    if (ConstantInt *ShAmt = dyn_cast<ConstantInt>(LHSI->getOperand(1))) {
-      if (Instruction *Res = foldICmpShrConst(ICI, BO, ShAmt))
-        return Res;
-    }
+  // If this is a signed comparison to 0 and the shift is sign preserving,
+  // use the shift LHS operand instead.
+  ICmpInst::Predicate pred = ICI.getPredicate();
+  if (isSignTest(pred, RHS) && cast<BinaryOperator>(LHSI)->hasNoSignedWrap())
+    return new ICmpInst(pred, LHSI->getOperand(0),
+                        Constant::getNullValue(RHS->getType()));
+
+  // Otherwise, if this is a comparison of the sign bit, simplify to and/test.
+  bool TrueIfSigned = false;
+  if (LHSI->hasOneUse() &&
+      isSignBitCheck(ICI.getPredicate(), RHS, TrueIfSigned)) {
+    // (X << 31) <s 0  --> (X&1) != 0
+    Constant *Mask = ConstantInt::get(
+        LHSI->getOperand(0)->getType(),
+        APInt::getOneBitSet(TypeBits, TypeBits - ShAmt->getZExtValue() - 1));
+    Value *And = Builder->CreateAnd(LHSI->getOperand(0), Mask,
+                                    LHSI->getName() + ".mask");
+    return new ICmpInst(TrueIfSigned ? ICmpInst::ICMP_NE : ICmpInst::ICMP_EQ,
+                        And, Constant::getNullValue(And->getType()));
+  }
 
-    // Handle exact shr's.
-    if (ICI.isEquality() && BO->isExact() && BO->hasOneUse()) {
-      if (RHSV->isMinValue())
-        return new ICmpInst(ICI.getPredicate(), BO->getOperand(0), RHS);
-    }
-    break;
+  // Transform (icmp pred iM (shl iM %v, N), CI)
+  // -> (icmp pred i(M-N) (trunc %v iM to i(M-N)), (trunc (CI>>N))
+  // Transform the shl to a trunc if (trunc (CI>>N)) has no loss and M-N.
+  // This enables to get rid of the shift in favor of a trunc which can be
+  // free on the target. It has the additional benefit of comparing to a
+  // smaller constant, which will be target friendly.
+  unsigned Amt = ShAmt->getLimitedValue(TypeBits - 1);
+  if (LHSI->hasOneUse() && Amt != 0 && RHSV->countTrailingZeros() >= Amt) {
+    Type *NTy = IntegerType::get(ICI.getContext(), TypeBits - Amt);
+    Constant *NCI = ConstantExpr::getTrunc(
+        ConstantExpr::getAShr(RHS, ConstantInt::get(RHS->getType(), Amt)), NTy);
+    return new ICmpInst(ICI.getPredicate(),
+                        Builder->CreateTrunc(LHSI->getOperand(0), NTy), NCI);
   }
 
-  case Instruction::UDiv:
-    if (ConstantInt *DivLHS = dyn_cast<ConstantInt>(LHSI->getOperand(0))) {
-      Value *X = LHSI->getOperand(1);
-      const APInt &C1 = RHS->getValue();
-      const APInt &C2 = DivLHS->getValue();
-      assert(C2 != 0 && "udiv 0, X should have been simplified already.");
-      // (icmp ugt (udiv C2, X), C1) -> (icmp ule X, C2/(C1+1))
-      if (ICI.getPredicate() == ICmpInst::ICMP_UGT) {
-        assert(!C1.isMaxValue() &&
-               "icmp ugt X, UINT_MAX should have been simplified already.");
-        return new ICmpInst(ICmpInst::ICMP_ULE, X,
-                            ConstantInt::get(X->getType(), C2.udiv(C1 + 1)));
-      }
-      // (icmp ult (udiv C2, X), C1) -> (icmp ugt X, C2/C1)
-      if (ICI.getPredicate() == ICmpInst::ICMP_ULT) {
-        assert(C1 != 0 && "icmp ult X, 0 should have been simplified already.");
-        return new ICmpInst(ICmpInst::ICMP_UGT, X,
-                            ConstantInt::get(X->getType(), C2.udiv(C1)));
-      }
+  return nullptr;
+}
+
+Instruction *InstCombiner::foldICmpShrConstant(ICmpInst &ICI, Instruction *LHSI,
+                                               const APInt *RHSV) {
+  // FIXME: This check restricts all folds under here to scalar types.
+  ConstantInt *RHS = dyn_cast<ConstantInt>(ICI.getOperand(1));
+  if (!RHS)
+    return nullptr;
+
+  // Handle equality comparisons of shift-by-constant.
+  BinaryOperator *BO = cast<BinaryOperator>(LHSI);
+  if (ConstantInt *ShAmt = dyn_cast<ConstantInt>(LHSI->getOperand(1))) {
+    if (Instruction *Res = foldICmpShrConstConst(ICI, BO, ShAmt))
+      return Res;
+  }
+
+  // Handle exact shr's.
+  if (ICI.isEquality() && BO->isExact() && BO->hasOneUse()) {
+    if (RHSV->isMinValue())
+      return new ICmpInst(ICI.getPredicate(), BO->getOperand(0), RHS);
+  }
+
+  return nullptr;
+}
+
+Instruction *InstCombiner::foldICmpUDivConstant(ICmpInst &ICI,
+                                                Instruction *LHSI,
+                                                const APInt *RHSV) {
+  // FIXME: This check restricts all folds under here to scalar types.
+  ConstantInt *RHS = dyn_cast<ConstantInt>(ICI.getOperand(1));
+  if (!RHS)
+    return nullptr;
+
+  if (ConstantInt *DivLHS = dyn_cast<ConstantInt>(LHSI->getOperand(0))) {
+    Value *X = LHSI->getOperand(1);
+    const APInt &C1 = RHS->getValue();
+    const APInt &C2 = DivLHS->getValue();
+    assert(C2 != 0 && "udiv 0, X should have been simplified already.");
+    // (icmp ugt (udiv C2, X), C1) -> (icmp ule X, C2/(C1+1))
+    if (ICI.getPredicate() == ICmpInst::ICMP_UGT) {
+      assert(!C1.isMaxValue() &&
+             "icmp ugt X, UINT_MAX should have been simplified already.");
+      return new ICmpInst(ICmpInst::ICMP_ULE, X,
+                          ConstantInt::get(X->getType(), C2.udiv(C1 + 1)));
     }
-  // fall-through
-  case Instruction::SDiv:
-    // Fold: icmp pred ([us]div X, C1), C2 -> range test
-    // Fold this div into the comparison, producing a range check.
-    // Determine, based on the divide type, what the range is being
-    // checked.  If there is an overflow on the low or high side, remember
-    // it, otherwise compute the range [low, hi) bounding the new value.
-    // See: InsertRangeTest above for the kinds of replacements possible.
-    if (ConstantInt *DivRHS = dyn_cast<ConstantInt>(LHSI->getOperand(1)))
-      if (Instruction *R = foldICmpDivConst(ICI, cast<BinaryOperator>(LHSI),
-                                          DivRHS))
-        return R;
-    break;
+    // (icmp ult (udiv C2, X), C1) -> (icmp ugt X, C2/C1)
+    if (ICI.getPredicate() == ICmpInst::ICMP_ULT) {
+      assert(C1 != 0 && "icmp ult X, 0 should have been simplified already.");
+      return new ICmpInst(ICmpInst::ICMP_UGT, X,
+                          ConstantInt::get(X->getType(), C2.udiv(C1)));
+    }
+  }
+
+  return nullptr;
+}
+
+Instruction *InstCombiner::foldICmpDivConstant(ICmpInst &ICI, Instruction *LHSI,
+                                               const APInt *RHSV) {
+  // FIXME: This check restricts all folds under here to scalar types.
+  ConstantInt *RHS = dyn_cast<ConstantInt>(ICI.getOperand(1));
+  if (!RHS)
+    return nullptr;
+
+  // Fold: icmp pred ([us]div X, C1), C2 -> range test
+  // Fold this div into the comparison, producing a range check.
+  // Determine, based on the divide type, what the range is being
+  // checked.  If there is an overflow on the low or high side, remember
+  // it, otherwise compute the range [low, hi) bounding the new value.
+  // See: InsertRangeTest above for the kinds of replacements possible.
+  if (ConstantInt *DivRHS = dyn_cast<ConstantInt>(LHSI->getOperand(1)))
+    if (Instruction *R =
+            foldICmpDivConstConst(ICI, cast<BinaryOperator>(LHSI), DivRHS))
+      return R;
+
+  return nullptr;
+}
+
+Instruction *InstCombiner::foldICmpSubConstant(ICmpInst &ICI, Instruction *LHSI,
+                                               const APInt *RHSV) {
+  // FIXME: This check restricts all folds under here to scalar types.
+  ConstantInt *RHS = dyn_cast<ConstantInt>(ICI.getOperand(1));
+  if (!RHS)
+    return nullptr;
+
+  ConstantInt *LHSC = dyn_cast<ConstantInt>(LHSI->getOperand(0));
+  if (!LHSC)
+    return nullptr;
+
+  const APInt &LHSV = LHSC->getValue();
+
+  // C1-X <u C2 -> (X|(C2-1)) == C1
+  //   iff C1 & (C2-1) == C2-1
+  //       C2 is a power of 2
+  if (ICI.getPredicate() == ICmpInst::ICMP_ULT && LHSI->hasOneUse() &&
+      RHSV->isPowerOf2() && (LHSV & (*RHSV - 1)) == (*RHSV - 1))
+    return new ICmpInst(ICmpInst::ICMP_EQ,
+                        Builder->CreateOr(LHSI->getOperand(1), *RHSV - 1),
+                        LHSC);
+
+  // C1-X >u C2 -> (X|C2) != C1
+  //   iff C1 & C2 == C2
+  //       C2+1 is a power of 2
+  if (ICI.getPredicate() == ICmpInst::ICMP_UGT && LHSI->hasOneUse() &&
+      (*RHSV + 1).isPowerOf2() && (LHSV & *RHSV) == *RHSV)
+    return new ICmpInst(ICmpInst::ICMP_NE,
+                        Builder->CreateOr(LHSI->getOperand(1), *RHSV), LHSC);
+
+  return nullptr;
+}
+
+Instruction *InstCombiner::foldICmpAddConstant(ICmpInst &ICI, Instruction *LHSI,
+                                               const APInt *RHSV) {
+  // FIXME: This check restricts all folds under here to scalar types.
+  ConstantInt *RHS = dyn_cast<ConstantInt>(ICI.getOperand(1));
+  if (!RHS)
+    return nullptr;
+
+  // Fold: icmp pred (add X, C1), C2
+  if (!ICI.isEquality()) {
+    ConstantInt *LHSC = dyn_cast<ConstantInt>(LHSI->getOperand(1));
+    if (!LHSC)
+      return nullptr;
 
-  case Instruction::Sub: {
-    ConstantInt *LHSC = dyn_cast<ConstantInt>(LHSI->getOperand(0));
-    if (!LHSC) break;
     const APInt &LHSV = LHSC->getValue();
+    ConstantRange CR =
+        ICI.makeConstantRange(ICI.getPredicate(), *RHSV).subtract(LHSV);
 
-    // C1-X <u C2 -> (X|(C2-1)) == C1
-    //   iff C1 & (C2-1) == C2-1
+    if (ICI.isSigned()) {
+      if (CR.getLower().isSignBit()) {
+        return new ICmpInst(ICmpInst::ICMP_SLT, LHSI->getOperand(0),
+                            Builder->getInt(CR.getUpper()));
+      } else if (CR.getUpper().isSignBit()) {
+        return new ICmpInst(ICmpInst::ICMP_SGE, LHSI->getOperand(0),
+                            Builder->getInt(CR.getLower()));
+      }
+    } else {
+      if (CR.getLower().isMinValue()) {
+        return new ICmpInst(ICmpInst::ICMP_ULT, LHSI->getOperand(0),
+                            Builder->getInt(CR.getUpper()));
+      } else if (CR.getUpper().isMinValue()) {
+        return new ICmpInst(ICmpInst::ICMP_UGE, LHSI->getOperand(0),
+                            Builder->getInt(CR.getLower()));
+      }
+    }
+
+    // X-C1 <u C2 -> (X & -C2) == C1
+    //   iff C1 & (C2-1) == 0
     //       C2 is a power of 2
     if (ICI.getPredicate() == ICmpInst::ICMP_ULT && LHSI->hasOneUse() &&
-        RHSV->isPowerOf2() && (LHSV & (*RHSV - 1)) == (*RHSV - 1))
+        RHSV->isPowerOf2() && (LHSV & (*RHSV - 1)) == 0)
       return new ICmpInst(ICmpInst::ICMP_EQ,
-                          Builder->CreateOr(LHSI->getOperand(1), *RHSV - 1),
-                          LHSC);
+                          Builder->CreateAnd(LHSI->getOperand(0), -(*RHSV)),
+                          ConstantExpr::getNeg(LHSC));
 
-    // C1-X >u C2 -> (X|C2) != C1
-    //   iff C1 & C2 == C2
+    // X-C1 >u C2 -> (X & ~C2) != C1
+    //   iff C1 & C2 == 0
     //       C2+1 is a power of 2
     if (ICI.getPredicate() == ICmpInst::ICMP_UGT && LHSI->hasOneUse() &&
-        (*RHSV + 1).isPowerOf2() && (LHSV & *RHSV) == *RHSV)
+        (*RHSV + 1).isPowerOf2() && (LHSV & *RHSV) == 0)
       return new ICmpInst(ICmpInst::ICMP_NE,
-                          Builder->CreateOr(LHSI->getOperand(1), *RHSV), LHSC);
-    break;
+                          Builder->CreateAnd(LHSI->getOperand(0), ~(*RHSV)),
+                          ConstantExpr::getNeg(LHSC));
   }
+  return nullptr;
+}
 
-  case Instruction::Add:
-    // Fold: icmp pred (add X, C1), C2
-    if (!ICI.isEquality()) {
-      ConstantInt *LHSC = dyn_cast<ConstantInt>(LHSI->getOperand(1));
-      if (!LHSC) break;
-      const APInt &LHSV = LHSC->getValue();
-
-      ConstantRange CR = ICI.makeConstantRange(ICI.getPredicate(), *RHSV)
-                            .subtract(LHSV);
-
-      if (ICI.isSigned()) {
-        if (CR.getLower().isSignBit()) {
-          return new ICmpInst(ICmpInst::ICMP_SLT, LHSI->getOperand(0),
-                              Builder->getInt(CR.getUpper()));
-        } else if (CR.getUpper().isSignBit()) {
-          return new ICmpInst(ICmpInst::ICMP_SGE, LHSI->getOperand(0),
-                              Builder->getInt(CR.getLower()));
-        }
-      } else {
-        if (CR.getLower().isMinValue()) {
-          return new ICmpInst(ICmpInst::ICMP_ULT, LHSI->getOperand(0),
-                              Builder->getInt(CR.getUpper()));
-        } else if (CR.getUpper().isMinValue()) {
-          return new ICmpInst(ICmpInst::ICMP_UGE, LHSI->getOperand(0),
-                              Builder->getInt(CR.getLower()));
-        }
-      }
+/// Try to fold integer comparisons with a constant operand: icmp Pred X, C.
+Instruction *InstCombiner::foldICmpWithConstant(ICmpInst &ICI) {
+  Instruction *LHSI;
+  const APInt *RHSV;
+  if (!match(ICI.getOperand(0), m_Instruction(LHSI)) ||
+      !match(ICI.getOperand(1), m_APInt(RHSV)))
+    return nullptr;
 
-      // X-C1 <u C2 -> (X & -C2) == C1
-      //   iff C1 & (C2-1) == 0
-      //       C2 is a power of 2
-      if (ICI.getPredicate() == ICmpInst::ICMP_ULT && LHSI->hasOneUse() &&
-          RHSV->isPowerOf2() && (LHSV & (*RHSV - 1)) == 0)
-        return new ICmpInst(ICmpInst::ICMP_EQ,
-                            Builder->CreateAnd(LHSI->getOperand(0), -(*RHSV)),
-                            ConstantExpr::getNeg(LHSC));
-
-      // X-C1 >u C2 -> (X & ~C2) != C1
-      //   iff C1 & C2 == 0
-      //       C2+1 is a power of 2
-      if (ICI.getPredicate() == ICmpInst::ICMP_UGT && LHSI->hasOneUse() &&
-          (*RHSV + 1).isPowerOf2() && (LHSV & *RHSV) == 0)
-        return new ICmpInst(ICmpInst::ICMP_NE,
-                            Builder->CreateAnd(LHSI->getOperand(0), ~(*RHSV)),
-                            ConstantExpr::getNeg(LHSC));
-    }
+  switch (LHSI->getOpcode()) {
+  case Instruction::Trunc:
+    if (Instruction *I = foldICmpTruncConstant(ICI, LHSI, RHSV))
+      return I;
+    break;
+  case Instruction::Xor:
+    if (Instruction *I = foldICmpXorConstant(ICI, LHSI, RHSV))
+      return I;
+    break;
+  case Instruction::And:
+    if (Instruction *I = foldICmpAndConstant(ICI, LHSI, RHSV))
+      return I;
+    break;
+  case Instruction::Or:
+    if (Instruction *I = foldICmpOrConstant(ICI, LHSI, RHSV))
+      return I;
+    break;
+  case Instruction::Mul:
+    if (Instruction *I = foldICmpMulConstant(ICI, LHSI, RHSV))
+      return I;
+    break;
+  case Instruction::Shl:
+    if (Instruction *I = foldICmpShlConstant(ICI, LHSI, RHSV))
+      return I;
+    break;
+  case Instruction::LShr:
+  case Instruction::AShr:
+    if (Instruction *I = foldICmpShrConstant(ICI, LHSI, RHSV))
+      return I;
+    break;
+  case Instruction::UDiv:
+    if (Instruction *I = foldICmpUDivConstant(ICI, LHSI, RHSV))
+      return I;
+    // fall-through
+  case Instruction::SDiv:
+    if (Instruction *I = foldICmpDivConstant(ICI, LHSI, RHSV))
+      return I;
+    break;
+  case Instruction::Sub:
+    if (Instruction *I = foldICmpSubConstant(ICI, LHSI, RHSV))
+      return I;
+    break;
+  case Instruction::Add:
+    if (Instruction *I = foldICmpAddConstant(ICI, LHSI, RHSV))
+      return I;
     break;
   }
 

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h?rev=278828&r1=278827&r2=278828&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h Tue Aug 16 12:54:36 2016
@@ -548,10 +548,10 @@ private:
                                             ConstantInt *AndCst = nullptr);
   Instruction *foldFCmpIntToFPConst(FCmpInst &I, Instruction *LHSI,
                                     Constant *RHSC);
-  Instruction *foldICmpDivConst(ICmpInst &ICI, BinaryOperator *DivI,
-                                ConstantInt *DivRHS);
-  Instruction *foldICmpShrConst(ICmpInst &ICI, BinaryOperator *DivI,
-                                ConstantInt *DivRHS);
+  Instruction *foldICmpDivConstConst(ICmpInst &ICI, BinaryOperator *DivI,
+                                     ConstantInt *DivRHS);
+  Instruction *foldICmpShrConstConst(ICmpInst &ICI, BinaryOperator *DivI,
+                                     ConstantInt *DivRHS);
   Instruction *foldICmpCstShrConst(ICmpInst &I, Value *Op, Value *A,
                                    ConstantInt *CI1, ConstantInt *CI2);
   Instruction *foldICmpCstShlConst(ICmpInst &I, Value *Op, Value *A,
@@ -560,6 +560,30 @@ private:
                                   ICmpInst::Predicate Pred);
   Instruction *foldICmpWithCastAndCast(ICmpInst &ICI);
   Instruction *foldICmpWithConstant(ICmpInst &ICI);
+
+  Instruction *foldICmpTruncConstant(ICmpInst &ICI, Instruction *LHSI,
+                                     const APInt *RHSV);
+  Instruction *foldICmpAndConstant(ICmpInst &ICI, Instruction *LHSI,
+                                   const APInt *RHSV);
+  Instruction *foldICmpXorConstant(ICmpInst &ICI, Instruction *LHSI,
+                                   const APInt *RHSV);
+  Instruction *foldICmpOrConstant(ICmpInst &ICI, Instruction *LHSI,
+                                  const APInt *RHSV);
+  Instruction *foldICmpMulConstant(ICmpInst &ICI, Instruction *LHSI,
+                                   const APInt *RHSV);
+  Instruction *foldICmpShlConstant(ICmpInst &ICI, Instruction *LHSI,
+                                   const APInt *RHSV);
+  Instruction *foldICmpShrConstant(ICmpInst &ICI, Instruction *LHSI,
+                                   const APInt *RHSV);
+  Instruction *foldICmpUDivConstant(ICmpInst &ICI, Instruction *LHSI,
+                                    const APInt *RHSV);
+  Instruction *foldICmpDivConstant(ICmpInst &ICI, Instruction *LHSI,
+                                   const APInt *RHSV);
+  Instruction *foldICmpSubConstant(ICmpInst &ICI, Instruction *LHSI,
+                                   const APInt *RHSV);
+  Instruction *foldICmpAddConstant(ICmpInst &ICI, Instruction *LHSI,
+                                   const APInt *RHSV);
+
   Instruction *foldICmpEqualityWithConstant(ICmpInst &ICI);
   Instruction *foldICmpIntrinsicWithConstant(ICmpInst &ICI);
 




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