[ValueTracking] Replace all uses of ComputeSignBit with computeKnownBits.

[craig.topper]

Summary

This patch finishes off the conversion of ComputeSignBit to computeKnownBits.

[RKSimon]

lib/Transforms/InstCombine/InstCombineInternal.h

496 ↗

(On Diff #98908)

Why on earth are we returning a void here?

[craig.topper]

lib/Transforms/InstCombine/InstCombineInternal.h

496 ↗

(On Diff #98908)

Fixed in a pre-commit. r303028

[davide]

LGTM

llvm/trunk/include/llvm/Analysis/ValueTracking.h

void computeKnownBitsFromRangeMetadata(const MDNode &Ranges,
                                          KnownBits &Known);
   /// Return true if LHS and RHS have no common bits set.
   bool haveNoCommonBitsSet(const Value *LHS, const Value *RHS,
                            const DataLayout &DL,
                            AssumptionCache *AC = nullptr,
                            const Instruction *CxtI = nullptr,
                            const DominatorTree *DT = nullptr);
 
-  /// Determine whether the sign bit is known to be zero or one. Convenience
-  /// wrapper around computeKnownBits.
-  void ComputeSignBit(const Value *V, bool &KnownZero, bool &KnownOne,
-                      const DataLayout &DL, unsigned Depth = 0,
-                      AssumptionCache *AC = nullptr,
-                      const Instruction *CxtI = nullptr,
-                      const DominatorTree *DT = nullptr);
-
   /// Return true if the given value is known to have exactly one bit set when
   /// defined. For vectors return true if every element is known to be a power
   /// of two when defined. Supports values with integer or pointer type and
   /// vectors of integers. If 'OrZero' is set, then return true if the given
   /// value is either a power of two or zero.
   bool isKnownToBeAPowerOfTwo(const Value *V, const DataLayout &DL,
                               bool OrZero = false, unsigned Depth = 0,
                               AssumptionCache *AC = nullptr,

llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp

 #include "llvm/IR/GlobalAlias.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Operator.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/KnownBits.h"
 #include <algorithm>
 
 #define DEBUG_TYPE "basicaa"
 
 using namespace llvm;
 
 /// Enable analysis of recursive PHI nodes.
 static cl::opt<bool> EnableRecPhiAnalysis("basicaa-recphi", cl::Hidden,
for (unsigned i = 0, e = DecompGEP1.VarIndices.size(); i != e; ++i) {
       Modulo |= (uint64_t)DecompGEP1.VarIndices[i].Scale;
 
       if (AllPositive) {
         // If the Value could change between cycles, then any reasoning about
         // the Value this cycle may not hold in the next cycle. We'll just
         // give up if we can't determine conditions that hold for every cycle:
         const Value *V = DecompGEP1.VarIndices[i].V;
 
-        bool SignKnownZero, SignKnownOne;
-        ComputeSignBit(V, SignKnownZero, SignKnownOne, DL, 0, &AC, nullptr, DT);
+        KnownBits Known = computeKnownBits(V, DL, 0, &AC, nullptr, DT);
+        bool SignKnownZero = Known.isNonNegative();
+        bool SignKnownOne = Known.isNegative();
 
         // Zero-extension widens the variable, and so forces the sign
         // bit to zero.
         bool IsZExt = DecompGEP1.VarIndices[i].ZExtBits > 0 || isa<ZExtInst>(V);
         SignKnownZero |= IsZExt;
         SignKnownOne &= !IsZExt;
 
         // If the variable begins with a zero then we know it's

llvm/trunk/lib/Analysis/InstructionSimplify.cpp

 
 /// Try hard to fold icmp with zero RHS because this is a common case.
 static Value *simplifyICmpWithZero(CmpInst::Predicate Pred, Value *LHS,
                                    Value *RHS, const SimplifyQuery &Q) {
   if (!match(RHS, m_Zero()))
     return nullptr;
 
   Type *ITy = GetCompareTy(LHS); // The return type.
-  bool LHSKnownNonNegative, LHSKnownNegative;
   switch (Pred) {
   default:
     llvm_unreachable("Unknown ICmp predicate!");
   case ICmpInst::ICMP_ULT:
     return getFalse(ITy);
   case ICmpInst::ICMP_UGE:
     return getTrue(ITy);
   case ICmpInst::ICMP_EQ:
   case ICmpInst::ICMP_ULE:
     if (isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
       return getFalse(ITy);
     break;
   case ICmpInst::ICMP_NE:
   case ICmpInst::ICMP_UGT:
     if (isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
       return getTrue(ITy);
     break;
-  case ICmpInst::ICMP_SLT:
-    ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC,
-                   Q.CxtI, Q.DT);
-    if (LHSKnownNegative)
+  case ICmpInst::ICMP_SLT: {
+    KnownBits LHSKnown = computeKnownBits(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
+    if (LHSKnown.isNegative())
       return getTrue(ITy);
-    if (LHSKnownNonNegative)
+    if (LHSKnown.isNonNegative())
       return getFalse(ITy);
     break;
-  case ICmpInst::ICMP_SLE:
-    ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC,
-                   Q.CxtI, Q.DT);
-    if (LHSKnownNegative)
+  }
+  case ICmpInst::ICMP_SLE: {
+    KnownBits LHSKnown = computeKnownBits(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
+    if (LHSKnown.isNegative())
       return getTrue(ITy);
-    if (LHSKnownNonNegative && isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
+    if (LHSKnown.isNonNegative() &&
+        isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
       return getFalse(ITy);
     break;
-  case ICmpInst::ICMP_SGE:
-    ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC,
-                   Q.CxtI, Q.DT);
-    if (LHSKnownNegative)
+  }
+  case ICmpInst::ICMP_SGE: {
+    KnownBits LHSKnown = computeKnownBits(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
+    if (LHSKnown.isNegative())
       return getFalse(ITy);
-    if (LHSKnownNonNegative)
+    if (LHSKnown.isNonNegative())
       return getTrue(ITy);
     break;
-  case ICmpInst::ICMP_SGT:
-    ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC,
-                   Q.CxtI, Q.DT);
-    if (LHSKnownNegative)
+  }
+  case ICmpInst::ICMP_SGT: {
+    KnownBits LHSKnown = computeKnownBits(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
+    if (LHSKnown.isNegative())
       return getFalse(ITy);
-    if (LHSKnownNonNegative && isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
+    if (LHSKnown.isNonNegative() &&
+        isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
       return getTrue(ITy);
     break;
   }
+  }
 
   return nullptr;
 }
 
 /// Many binary operators with a constant operand have an easy-to-compute
 /// range of outputs. This can be used to fold a comparison to always true or
 /// always false.
 static void setLimitsForBinOp(BinaryOperator &BO, APInt &Lower, APInt &Upper) {
if (MaxRecurse && (LBO || RBO)) {
     // icmp pred (or X, Y), X
     if (LBO && match(LBO, m_c_Or(m_Value(Y), m_Specific(RHS)))) {
       if (Pred == ICmpInst::ICMP_ULT)
         return getFalse(ITy);
       if (Pred == ICmpInst::ICMP_UGE)
         return getTrue(ITy);
 
       if (Pred == ICmpInst::ICMP_SLT || Pred == ICmpInst::ICMP_SGE) {
-        bool RHSKnownNonNegative, RHSKnownNegative;
-        bool YKnownNonNegative, YKnownNegative;
-        ComputeSignBit(RHS, RHSKnownNonNegative, RHSKnownNegative, Q.DL, 0,
-                       Q.AC, Q.CxtI, Q.DT);
-        ComputeSignBit(Y, YKnownNonNegative, YKnownNegative, Q.DL, 0, Q.AC,
-                       Q.CxtI, Q.DT);
-        if (RHSKnownNonNegative && YKnownNegative)
+        KnownBits RHSKnown = computeKnownBits(RHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
+        KnownBits YKnown = computeKnownBits(Y, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
+        if (RHSKnown.isNonNegative() && YKnown.isNegative())
           return Pred == ICmpInst::ICMP_SLT ? getTrue(ITy) : getFalse(ITy);
-        if (RHSKnownNegative || YKnownNonNegative)
+        if (RHSKnown.isNegative() || YKnown.isNonNegative())
           return Pred == ICmpInst::ICMP_SLT ? getFalse(ITy) : getTrue(ITy);
       }
     }
     // icmp pred X, (or X, Y)
     if (RBO && match(RBO, m_c_Or(m_Value(Y), m_Specific(LHS)))) {
       if (Pred == ICmpInst::ICMP_ULE)
         return getTrue(ITy);
       if (Pred == ICmpInst::ICMP_UGT)
         return getFalse(ITy);
 
       if (Pred == ICmpInst::ICMP_SGT || Pred == ICmpInst::ICMP_SLE) {
-        bool LHSKnownNonNegative, LHSKnownNegative;
-        bool YKnownNonNegative, YKnownNegative;
-        ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0,
-                       Q.AC, Q.CxtI, Q.DT);
-        ComputeSignBit(Y, YKnownNonNegative, YKnownNegative, Q.DL, 0, Q.AC,
-                       Q.CxtI, Q.DT);
-        if (LHSKnownNonNegative && YKnownNegative)
+        KnownBits LHSKnown = computeKnownBits(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
+        KnownBits YKnown = computeKnownBits(Y, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
+        if (LHSKnown.isNonNegative() && YKnown.isNegative())
           return Pred == ICmpInst::ICMP_SGT ? getTrue(ITy) : getFalse(ITy);
-        if (LHSKnownNegative || YKnownNonNegative)
+        if (LHSKnown.isNegative() || YKnown.isNonNegative())
           return Pred == ICmpInst::ICMP_SGT ? getFalse(ITy) : getTrue(ITy);
       }
     }
   }
 
   // icmp pred (and X, Y), X
   if (LBO && match(LBO, m_CombineOr(m_And(m_Value(), m_Specific(RHS)),
                                     m_And(m_Specific(RHS), m_Value())))) {
if (ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS)) {
         if (Pred == ICmpInst::ICMP_SGT)
           return ConstantInt::getFalse(RHSC->getContext());
       }
     }
   }
 
   // icmp pred (urem X, Y), Y
   if (LBO && match(LBO, m_URem(m_Value(), m_Specific(RHS)))) {
-    bool KnownNonNegative, KnownNegative;
     switch (Pred) {
     default:
       break;
     case ICmpInst::ICMP_SGT:
-    case ICmpInst::ICMP_SGE:
-      ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC,
-                     Q.CxtI, Q.DT);
-      if (!KnownNonNegative)
+    case ICmpInst::ICMP_SGE: {
+      KnownBits Known = computeKnownBits(RHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
+      if (!Known.isNonNegative())
         break;
       LLVM_FALLTHROUGH;
+    }
     case ICmpInst::ICMP_EQ:
     case ICmpInst::ICMP_UGT:
     case ICmpInst::ICMP_UGE:
       return getFalse(ITy);
     case ICmpInst::ICMP_SLT:
-    case ICmpInst::ICMP_SLE:
-      ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC,
-                     Q.CxtI, Q.DT);
-      if (!KnownNonNegative)
+    case ICmpInst::ICMP_SLE: {
+      KnownBits Known = computeKnownBits(RHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
+      if (!Known.isNonNegative())
         break;
       LLVM_FALLTHROUGH;
+    }
     case ICmpInst::ICMP_NE:
     case ICmpInst::ICMP_ULT:
     case ICmpInst::ICMP_ULE:
       return getTrue(ITy);
     }
   }
 
   // icmp pred X, (urem Y, X)
   if (RBO && match(RBO, m_URem(m_Value(), m_Specific(LHS)))) {
-    bool KnownNonNegative, KnownNegative;
     switch (Pred) {
     default:
       break;
     case ICmpInst::ICMP_SGT:
-    case ICmpInst::ICMP_SGE:
-      ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC,
-                     Q.CxtI, Q.DT);
-      if (!KnownNonNegative)
+    case ICmpInst::ICMP_SGE: {
+      KnownBits Known = computeKnownBits(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
+      if (!Known.isNonNegative())
         break;
       LLVM_FALLTHROUGH;
+    }
     case ICmpInst::ICMP_NE:
     case ICmpInst::ICMP_UGT:
     case ICmpInst::ICMP_UGE:
       return getTrue(ITy);
     case ICmpInst::ICMP_SLT:
-    case ICmpInst::ICMP_SLE:
-      ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC,
-                     Q.CxtI, Q.DT);
-      if (!KnownNonNegative)
+    case ICmpInst::ICMP_SLE: {
+      KnownBits Known = computeKnownBits(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
+      if (!Known.isNonNegative())
         break;
       LLVM_FALLTHROUGH;
+    }
     case ICmpInst::ICMP_EQ:
     case ICmpInst::ICMP_ULT:
     case ICmpInst::ICMP_ULE:
       return getFalse(ITy);
     }
   }
 
   // x >> y <=u x

llvm/trunk/lib/Analysis/ScalarEvolution.cpp

ScalarEvolution::ExitLimit ScalarEvolution::computeShiftCompareExitLimit(
   switch (OpCode) {
   default:
     llvm_unreachable("Impossible case!");
 
   case Instruction::AShr: {
     // {K,ashr,<positive-constant>} stabilizes to signum(K) in at most
     // bitwidth(K) iterations.
     Value *FirstValue = PN->getIncomingValueForBlock(Predecessor);
-    bool KnownZero, KnownOne;
-    ComputeSignBit(FirstValue, KnownZero, KnownOne, DL, 0, nullptr,
+    KnownBits Known = computeKnownBits(FirstValue, DL, 0, nullptr,
                                        Predecessor->getTerminator(), &DT);
     auto *Ty = cast<IntegerType>(RHS->getType());
-    if (KnownZero)
+    if (Known.isNonNegative())
       StableValue = ConstantInt::get(Ty, 0);
-    else if (KnownOne)
+    else if (Known.isNegative())
       StableValue = ConstantInt::get(Ty, -1, true);
     else
       return getCouldNotCompute();
 
     break;
   }
   case Instruction::LShr:
   case Instruction::Shl:

llvm/trunk/lib/Analysis/ValueTracking.cpp

bool llvm::haveNoCommonBitsSet(const Value *LHS, const Value *RHS,
   KnownBits LHSKnown(IT->getBitWidth());
   KnownBits RHSKnown(IT->getBitWidth());
   computeKnownBits(LHS, LHSKnown, DL, 0, AC, CxtI, DT);
   computeKnownBits(RHS, RHSKnown, DL, 0, AC, CxtI, DT);
   return (LHSKnown.Zero | RHSKnown.Zero).isAllOnesValue();
 }
 
 
-void llvm::ComputeSignBit(const Value *V, bool &KnownZero, bool &KnownOne,
-                          const DataLayout &DL, unsigned Depth,
-                          AssumptionCache *AC, const Instruction *CxtI,
-                          const DominatorTree *DT) {
-  KnownBits Known = computeKnownBits(V, DL, Depth, AC, CxtI, DT);
-  KnownZero = Known.isNonNegative();
-  KnownOne = Known.isNegative();
-}
-
 static bool isKnownToBeAPowerOfTwo(const Value *V, bool OrZero, unsigned Depth,
                                    const Query &Q);
 
 bool llvm::isKnownToBeAPowerOfTwo(const Value *V, const DataLayout &DL,
                                   bool OrZero,
                                   unsigned Depth, AssumptionCache *AC,
                                   const Instruction *CxtI,
                                   const DominatorTree *DT) {

llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp

bool InstCombiner::WillNotOverflowSignedSub(Value *LHS, Value *RHS,
   return false;
 }
 
 /// \brief Return true if we can prove that:
 ///    (sub LHS, RHS)  === (sub nuw LHS, RHS)
 bool InstCombiner::WillNotOverflowUnsignedSub(Value *LHS, Value *RHS,
                                               Instruction &CxtI) {
   // If the LHS is negative and the RHS is non-negative, no unsigned wrap.
-  bool LHSKnownNonNegative, LHSKnownNegative;
-  bool RHSKnownNonNegative, RHSKnownNegative;
-  ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, /*Depth=*/0,
-                 &CxtI);
-  ComputeSignBit(RHS, RHSKnownNonNegative, RHSKnownNegative, /*Depth=*/0,
-                 &CxtI);
-  if (LHSKnownNegative && RHSKnownNonNegative)
+  KnownBits LHSKnown = computeKnownBits(LHS, /*Depth=*/0, &CxtI);
+  KnownBits RHSKnown = computeKnownBits(RHS, /*Depth=*/0, &CxtI);
+  if (LHSKnown.isNegative() && RHSKnown.isNonNegative())
     return true;
 
   return false;
 }
 
 // Checks if any operand is negative and we can convert add to sub.
 // This function checks for following negative patterns
 //   ADD(XOR(OR(Z, NOT(C)), C)), 1) == NEG(AND(Z, C))

llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp

Value *InstCombiner::simplifyRangeCheck(ICmpInst *Cmp0, ICmpInst *Cmp1,
   ICmpInst::Predicate NewPred;
   switch (Pred1) {
     case ICmpInst::ICMP_SLT: NewPred = ICmpInst::ICMP_ULT; break;
     case ICmpInst::ICMP_SLE: NewPred = ICmpInst::ICMP_ULE; break;
     default: return nullptr;
   }
 
   // This simplification is only valid if the upper range is not negative.
-  bool IsNegative, IsNotNegative;
-  ComputeSignBit(RangeEnd, IsNotNegative, IsNegative, /*Depth=*/0, Cmp1);
-  if (!IsNotNegative)
+  KnownBits Known = computeKnownBits(RangeEnd, /*Depth=*/0, Cmp1);
+  if (!Known.isNonNegative())
     return nullptr;
 
   if (Inverted)
     NewPred = ICmpInst::getInversePredicate(NewPred);
 
   return Builder->CreateICmp(NewPred, Input, RangeEnd);
 }
 

llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp

Instruction *InstCombiner::visitSExt(SExtInst &CI) {
   if (Instruction *I = commonCastTransforms(CI))
     return I;
 
   Value *Src = CI.getOperand(0);
   Type *SrcTy = Src->getType(), *DestTy = CI.getType();
 
   // If we know that the value being extended is positive, we can use a zext
   // instead.
-  bool KnownZero, KnownOne;
-  ComputeSignBit(Src, KnownZero, KnownOne, 0, &CI);
-  if (KnownZero) {
+  KnownBits Known = computeKnownBits(Src, 0, &CI);
+  if (Known.isNonNegative()) {
     Value *ZExt = Builder->CreateZExt(Src, DestTy);
     return replaceInstUsesWith(CI, ZExt);
   }
 
   // Attempt to extend the entire input expression tree to the destination
   // type.   Only do this if the dest type is a simple type, don't convert the
   // expression tree to something weird like i93 unless the source is also
   // strange.

llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h

 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/InstVisitor.h"
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Operator.h"
 #include "llvm/IR/PatternMatch.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/Dwarf.h"
+#include "llvm/Support/KnownBits.h"
 #include "llvm/Transforms/InstCombine/InstCombineWorklist.h"
 #include "llvm/Transforms/Utils/Local.h"
 
 #define DEBUG_TYPE "instcombine"
 
 namespace llvm {
 class CallSite;
 class DataLayout;
Instruction *eraseInstFromFunction(Instruction &I) {
     MadeIRChange = true;
     return nullptr; // Don't do anything with FI
   }
 
   void computeKnownBits(Value *V, KnownBits &Known,
                         unsigned Depth, Instruction *CxtI) const {
     llvm::computeKnownBits(V, Known, DL, Depth, &AC, CxtI, &DT);
   }
+  KnownBits computeKnownBits(Value *V, unsigned Depth,
+                             Instruction *CxtI) const {
+    return llvm::computeKnownBits(V, DL, Depth, &AC, CxtI, &DT);
+  }
 
   bool MaskedValueIsZero(Value *V, const APInt &Mask, unsigned Depth = 0,
                          Instruction *CxtI = nullptr) const {
     return llvm::MaskedValueIsZero(V, Mask, DL, Depth, &AC, CxtI, &DT);
   }
   unsigned ComputeNumSignBits(Value *Op, unsigned Depth = 0,
                               Instruction *CxtI = nullptr) const {
     return llvm::ComputeNumSignBits(Op, DL, Depth, &AC, CxtI, &DT);
   }
-  void ComputeSignBit(Value *V, bool &KnownZero, bool &KnownOne,
-                      unsigned Depth = 0, Instruction *CxtI = nullptr) const {
-    llvm::ComputeSignBit(V, KnownZero, KnownOne, DL, Depth, &AC, CxtI, &DT);
-  }
   OverflowResult computeOverflowForUnsignedMul(Value *LHS, Value *RHS,
                                                const Instruction *CxtI) {
     return llvm::computeOverflowForUnsignedMul(LHS, RHS, DL, &AC, CxtI, &DT);
   }
   OverflowResult computeOverflowForUnsignedAdd(Value *LHS, Value *RHS,
                                                const Instruction *CxtI) {
     return llvm::computeOverflowForUnsignedAdd(LHS, RHS, DL, &AC, CxtI, &DT);
   }

llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp

static bool canReplaceGEPIdxWithZero(InstCombiner &IC, GetElementPtrInst *GEPI,
   uint64_t TyAllocSize = DL.getTypeAllocSize(AllocTy);
 
   // If there are more indices after the one we might replace with a zero, make
   // sure they're all non-negative. If any of them are negative, the overall
   // address being computed might be before the base address determined by the
   // first non-zero index.
   auto IsAllNonNegative = [&]() {
     for (unsigned i = Idx+1, e = GEPI->getNumOperands(); i != e; ++i) {
-      bool KnownNonNegative, KnownNegative;
-      IC.ComputeSignBit(GEPI->getOperand(i), KnownNonNegative,
-                        KnownNegative, 0, MemI);
-      if (KnownNonNegative)
+      KnownBits Known = IC.computeKnownBits(GEPI->getOperand(i), 0, MemI);
+      if (Known.isNonNegative())
         continue;
       return false;
     }
 
     return true;
   };
 
   // FIXME: If the GEP is not inbounds, and there are extra indices after the

llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp

bool InstCombiner::WillNotOverflowSignedMul(Value *LHS, Value *RHS,
   //   SignBits == BitWidth
   // The second case is difficult to check, therefore we only handle the
   // first case.
   if (SignBits == BitWidth + 1) {
     // It overflows only when both arguments are negative and the true
     // product is exactly the minimum negative number.
     // E.g. mul i16 with 17 sign bits: 0xff00 * 0xff80 = 0x8000
     // For simplicity we just check if at least one side is not negative.
-    bool LHSNonNegative, LHSNegative;
-    bool RHSNonNegative, RHSNegative;
-    ComputeSignBit(LHS, LHSNonNegative, LHSNegative, /*Depth=*/0, &CxtI);
-    ComputeSignBit(RHS, RHSNonNegative, RHSNegative, /*Depth=*/0, &CxtI);
-    if (LHSNonNegative || RHSNonNegative)
+    KnownBits LHSKnown = computeKnownBits(LHS, /*Depth=*/0, &CxtI);
+    KnownBits RHSKnown = computeKnownBits(RHS, /*Depth=*/0, &CxtI);
+    if (LHSKnown.isNonNegative() || RHSKnown.isNonNegative())
       return true;
   }
   return false;
 }
 
 Instruction *InstCombiner::visitMul(BinaryOperator &I) {
   bool Changed = SimplifyAssociativeOrCommutative(I);
   Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);

llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp

 #include "llvm/IR/NoFolder.h"
 #include "llvm/IR/Type.h"
 #include "llvm/IR/Value.h"
 #include "llvm/IR/Verifier.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/GraphWriter.h"
+#include "llvm/Support/KnownBits.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Utils/LoopUtils.h"
 #include "llvm/Transforms/Vectorize.h"
 #include <algorithm>
 #include <memory>
 
 using namespace llvm;
 using namespace slpvectorizer;
void BoUpSLP::computeMinimumValueSizes() {
   // maximum bit width required to store the scalar by using ValueTracking to
   // compute the number of high-order bits we can truncate.
   if (MaxBitWidth == DL->getTypeSizeInBits(TreeRoot[0]->getType())) {
     MaxBitWidth = 8u;
 
     // Determine if the sign bit of all the roots is known to be zero. If not,
     // IsKnownPositive is set to False.
     IsKnownPositive = all_of(TreeRoot, [&](Value *R) {
-      bool KnownZero = false;
-      bool KnownOne = false;
-      ComputeSignBit(R, KnownZero, KnownOne, *DL);
-      return KnownZero;
+      KnownBits Known = computeKnownBits(R, *DL);
+      return Known.isNonNegative();
     });
 
     // Determine the maximum number of bits required to store the scalar
     // values.
     for (auto *Scalar : ToDemote) {
       auto NumSignBits = ComputeNumSignBits(Scalar, *DL, 0, AC, 0, DT);
       auto NumTypeBits = DL->getTypeSizeInBits(Scalar->getType());
       MaxBitWidth = std::max<unsigned>(NumTypeBits - NumSignBits, MaxBitWidth);