1 files changed, 43 insertions, 36 deletions

diff --git a/lib/IR/Constants.cpp b/lib/IR/Constants.cpp
index 027946efd1..2d67c0c943 100644
--- a/lib/IR/Constants.cpp
+++ b/lib/IR/Constants.cpp
@@ -47,6 +47,16 @@ bool Constant::isNegativeZeroValue() const {
   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
     return CFP->isZero() && CFP->isNegative();
 
+  // Equivalent for a vector of -0.0's.
+  if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
+    if (ConstantFP *SplatCFP = dyn_cast_or_null<ConstantFP>(CV->getSplatValue()))
+      if (SplatCFP && SplatCFP->isZero() && SplatCFP->isNegative())
+        return true;
+
+  // We've already handled true FP case; any other FP vectors can't represent -0.0.
+  if (getType()->isFPOrFPVectorTy())
+    return false;
+
   // Otherwise, just use +0.0.
   return isNullValue();
 }
@@ -227,18 +237,21 @@ void Constant::destroyConstantImpl() {
   delete this;
 }
 
-/// canTrap - Return true if evaluation of this constant could trap.  This is
-/// true for things like constant expressions that could divide by zero.
-bool Constant::canTrap() const {
-  assert(getType()->isFirstClassType() && "Cannot evaluate aggregate vals!");
+static bool canTrapImpl(const Constant *C,
+                        SmallPtrSet<const ConstantExpr *, 4> &NonTrappingOps) {
+  assert(C->getType()->isFirstClassType() && "Cannot evaluate aggregate vals!");
   // The only thing that could possibly trap are constant exprs.
-  const ConstantExpr *CE = dyn_cast<ConstantExpr>(this);
-  if (!CE) return false;
+  const ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
+  if (!CE)
+    return false;
 
   // ConstantExpr traps if any operands can trap.
-  for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
-    if (CE->getOperand(i)->canTrap())
-      return true;
+  for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i) {
+    if (ConstantExpr *Op = dyn_cast<ConstantExpr>(CE->getOperand(i))) {
+      if (NonTrappingOps.insert(Op) && canTrapImpl(Op, NonTrappingOps))
+        return true;
+    }
+  }
 
   // Otherwise, only specific operations can trap.
   switch (CE->getOpcode()) {
@@ -257,6 +270,13 @@ bool Constant::canTrap() const {
   }
 }
 
+/// canTrap - Return true if evaluation of this constant could trap.  This is
+/// true for things like constant expressions that could divide by zero.
+bool Constant::canTrap() const {
+  SmallPtrSet<const ConstantExpr *, 4> NonTrappingOps;
+  return canTrapImpl(this, NonTrappingOps);
+}
+
 /// isThreadDependent - Return true if the value can vary between threads.
 bool Constant::isThreadDependent() const {
   SmallPtrSet<const Constant*, 64> Visited;
@@ -1416,9 +1436,8 @@ static inline Constant *getFoldedCast(
 
   LLVMContextImpl *pImpl = Ty->getContext().pImpl;
 
-  // Look up the constant in the table first to ensure uniqueness
-  std::vector<Constant*> argVec(1, C);
-  ExprMapKeyType Key(opc, argVec);
+  // Look up the constant in the table first to ensure uniqueness.
+  ExprMapKeyType Key(opc, C);
 
   return pImpl->ExprConstants.getOrCreate(Ty, Key);
 }
@@ -1715,9 +1734,8 @@ Constant *ConstantExpr::get(unsigned Opcode, Constant *C1, Constant *C2,
   if (Constant *FC = ConstantFoldBinaryInstruction(Opcode, C1, C2))
     return FC;          // Fold a few common cases.
 
-  std::vector<Constant*> argVec(1, C1);
-  argVec.push_back(C2);
-  ExprMapKeyType Key(Opcode, argVec, 0, Flags);
+  Constant *ArgVec[] = { C1, C2 };
+  ExprMapKeyType Key(Opcode, ArgVec, 0, Flags);
 
   LLVMContextImpl *pImpl = C1->getContext().pImpl;
   return pImpl->ExprConstants.getOrCreate(C1->getType(), Key);
@@ -1793,10 +1811,8 @@ Constant *ConstantExpr::getSelect(Constant *C, Constant *V1, Constant *V2) {
   if (Constant *SC = ConstantFoldSelectInstruction(C, V1, V2))
     return SC;        // Fold common cases
 
-  std::vector<Constant*> argVec(3, C);
-  argVec[1] = V1;
-  argVec[2] = V2;
-  ExprMapKeyType Key(Instruction::Select, argVec);
+  Constant *ArgVec[] = { C, V1, V2 };
+  ExprMapKeyType Key(Instruction::Select, ArgVec);
 
   LLVMContextImpl *pImpl = C->getContext().pImpl;
   return pImpl->ExprConstants.getOrCreate(V1->getType(), Key);
@@ -1848,9 +1864,7 @@ ConstantExpr::getICmp(unsigned short pred, Constant *LHS, Constant *RHS) {
     return FC;          // Fold a few common cases...
 
   // Look up the constant in the table first to ensure uniqueness
-  std::vector<Constant*> ArgVec;
-  ArgVec.push_back(LHS);
-  ArgVec.push_back(RHS);
+  Constant *ArgVec[] = { LHS, RHS };
   // Get the key type with both the opcode and predicate
   const ExprMapKeyType Key(Instruction::ICmp, ArgVec, pred);
 
@@ -1871,9 +1885,7 @@ ConstantExpr::getFCmp(unsigned short pred, Constant *LHS, Constant *RHS) {
     return FC;          // Fold a few common cases...
 
   // Look up the constant in the table first to ensure uniqueness
-  std::vector<Constant*> ArgVec;
-  ArgVec.push_back(LHS);
-  ArgVec.push_back(RHS);
+  Constant *ArgVec[] = { LHS, RHS };
   // Get the key type with both the opcode and predicate
   const ExprMapKeyType Key(Instruction::FCmp, ArgVec, pred);
 
@@ -1895,9 +1907,8 @@ Constant *ConstantExpr::getExtractElement(Constant *Val, Constant *Idx) {
     return FC;          // Fold a few common cases.
 
   // Look up the constant in the table first to ensure uniqueness
-  std::vector<Constant*> ArgVec(1, Val);
-  ArgVec.push_back(Idx);
-  const ExprMapKeyType Key(Instruction::ExtractElement,ArgVec);
+  Constant *ArgVec[] = { Val, Idx };
+  const ExprMapKeyType Key(Instruction::ExtractElement, ArgVec);
 
   LLVMContextImpl *pImpl = Val->getContext().pImpl;
   Type *ReqTy = Val->getType()->getVectorElementType();
@@ -1916,10 +1927,8 @@ Constant *ConstantExpr::getInsertElement(Constant *Val, Constant *Elt,
   if (Constant *FC = ConstantFoldInsertElementInstruction(Val, Elt, Idx))
     return FC;          // Fold a few common cases.
   // Look up the constant in the table first to ensure uniqueness
-  std::vector<Constant*> ArgVec(1, Val);
-  ArgVec.push_back(Elt);
-  ArgVec.push_back(Idx);
-  const ExprMapKeyType Key(Instruction::InsertElement,ArgVec);
+  Constant *ArgVec[] = { Val, Elt, Idx };
+  const ExprMapKeyType Key(Instruction::InsertElement, ArgVec);
 
   LLVMContextImpl *pImpl = Val->getContext().pImpl;
   return pImpl->ExprConstants.getOrCreate(Val->getType(), Key);
@@ -1938,10 +1947,8 @@ Constant *ConstantExpr::getShuffleVector(Constant *V1, Constant *V2,
   Type *ShufTy = VectorType::get(EltTy, NElts);
 
   // Look up the constant in the table first to ensure uniqueness
-  std::vector<Constant*> ArgVec(1, V1);
-  ArgVec.push_back(V2);
-  ArgVec.push_back(Mask);
-  const ExprMapKeyType Key(Instruction::ShuffleVector,ArgVec);
+  Constant *ArgVec[] = { V1, V2, Mask };
+  const ExprMapKeyType Key(Instruction::ShuffleVector, ArgVec);
 
   LLVMContextImpl *pImpl = ShufTy->getContext().pImpl;
   return pImpl->ExprConstants.getOrCreate(ShufTy, Key);