const User *U = *UI;
if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(U)) {
GS.HasNonInstructionUser = true;
+
+ // If the result of the constantexpr isn't pointer type, then we won't
+ // know to expect it in various places. Just reject early.
+ if (!isa<PointerType>(CE->getType())) return true;
+
if (AnalyzeGlobal(CE, GS, PHIUsers)) return true;
} else if (const Instruction *I = dyn_cast<Instruction>(U)) {
if (!GS.HasMultipleAccessingFunctions) {
/// isSimpleEnoughPointerToCommit - Return true if this constant is simple
-/// enough for us to understand. In particular, if it is a cast of something,
-/// we punt. We basically just support direct accesses to globals and GEP's of
+/// enough for us to understand. In particular, if it is a cast to anything
+/// other than from one pointer type to another pointer type, we punt.
+/// We basically just support direct accesses to globals and GEP's of
/// globals. This should be kept up to date with CommitValueTo.
static bool isSimpleEnoughPointerToCommit(Constant *C) {
// Conservatively, avoid aggregate types. This is because we don't
// external globals.
return GV->hasUniqueInitializer();
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
// Handle a constantexpr gep.
if (CE->getOpcode() == Instruction::GetElementPtr &&
isa<GlobalVariable>(CE->getOperand(0)) &&
return false;
return ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE);
+
+ // A constantexpr bitcast from a pointer to another pointer is a no-op,
+ // and we know how to evaluate it by moving the bitcast from the pointer
+ // operand to the value operand.
+ } else if (CE->getOpcode() == Instruction::BitCast &&
+ isa<GlobalVariable>(CE->getOperand(0))) {
+ // Do not allow weak/*_odr/linkonce/dllimport/dllexport linkage or
+ // external globals.
+ return cast<GlobalVariable>(CE->getOperand(0))->hasUniqueInitializer();
}
+ }
+
return false;
}
std::vector<Function*> &CallStack,
DenseMap<Constant*, Constant*> &MutatedMemory,
std::vector<GlobalVariable*> &AllocaTmps,
- SmallPtrSet<Constant*, 8> &SimpleConstants) {
+ SmallPtrSet<Constant*, 8> &SimpleConstants,
+ const TargetData *TD) {
// Check to see if this function is already executing (recursion). If so,
// bail out. TODO: we might want to accept limited recursion.
if (std::find(CallStack.begin(), CallStack.end(), F) != CallStack.end())
// of one global variable divided by another) then we can't commit it.
if (!isSimpleEnoughValueToCommit(Val, SimpleConstants))
return false;
+
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
+ if (CE->getOpcode() == Instruction::BitCast) {
+ // If we're evaluating a store through a bitcast, then we need
+ // to pull the bitcast off the pointer type and push it onto the
+ // stored value.
+ Ptr = CE->getOperand(0);
+
+ const Type *NewTy=cast<PointerType>(Ptr->getType())->getElementType();
+
+ // A bitcast'd pointer implicitly points to the first field of a
+ // struct. Insert implicity "gep @x, 0, 0, ..." until we get down
+ // to the first concrete member.
+ // FIXME: This could be extended to work for arrays as well.
+ while (const StructType *STy = dyn_cast<StructType>(NewTy)) {
+ NewTy = STy->getTypeAtIndex(0U);
+
+ const IntegerType *IdxTy =IntegerType::get(NewTy->getContext(), 32);
+ Constant *IdxZero = ConstantInt::get(IdxTy, 0, false);
+ Constant * const IdxList[] = {IdxZero, IdxZero};
+
+ Ptr = ConstantExpr::getGetElementPtr(Ptr, IdxList, 2);
+ }
+
+ if (!isa<PointerType>(NewTy)) return false;
+ Val = ConstantExpr::getBitCast(Val, NewTy);
+ }
+
MutatedMemory[Ptr] = Val;
} else if (BinaryOperator *BO = dyn_cast<BinaryOperator>(CurInst)) {
InstResult = ConstantExpr::get(BO->getOpcode(),
Constant *RetVal;
// Execute the call, if successful, use the return value.
if (!EvaluateFunction(Callee, RetVal, Formals, CallStack,
- MutatedMemory, AllocaTmps, SimpleConstants))
+ MutatedMemory, AllocaTmps, SimpleConstants, TD))
return false;
InstResult = RetVal;
}
return false;
}
- if (!CurInst->use_empty())
+ if (!CurInst->use_empty()) {
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(InstResult))
+ InstResult = ConstantFoldConstantExpression(CE, TD);
+
Values[CurInst] = InstResult;
+ }
// Advance program counter.
++CurInst;
/// EvaluateStaticConstructor - Evaluate static constructors in the function, if
/// we can. Return true if we can, false otherwise.
-static bool EvaluateStaticConstructor(Function *F) {
+static bool EvaluateStaticConstructor(Function *F, const TargetData *TD) {
/// MutatedMemory - For each store we execute, we update this map. Loads
/// check this to get the most up-to-date value. If evaluation is successful,
/// this state is committed to the process.
bool EvalSuccess = EvaluateFunction(F, RetValDummy,
SmallVector<Constant*, 0>(), CallStack,
MutatedMemory, AllocaTmps,
- SimpleConstants);
+ SimpleConstants, TD);
+
if (EvalSuccess) {
// We succeeded at evaluation: commit the result.
DEBUG(dbgs() << "FULLY EVALUATED GLOBAL CTOR FUNCTION '"
bool MadeChange = false;
if (Ctors.empty()) return false;
+ const TargetData *TD = getAnalysisIfAvailable<TargetData>();
// Loop over global ctors, optimizing them when we can.
for (unsigned i = 0; i != Ctors.size(); ++i) {
Function *F = Ctors[i];
if (F->empty()) continue;
// If we can evaluate the ctor at compile time, do.
- if (EvaluateStaticConstructor(F)) {
+ if (EvaluateStaticConstructor(F, TD)) {
Ctors.erase(Ctors.begin()+i);
MadeChange = true;
--i;
projects / oota-llvm.git / blobdiff