[llvm-commits] [llvm] r44849 - /llvm/trunk/lib/VMCore/ConstantFold.cpp
Chris Lattner
sabre at nondot.org
Mon Dec 10 21:55:02 PST 2007
Author: lattner
Date: Mon Dec 10 23:55:02 2007
New Revision: 44849
URL: http://llvm.org/viewvc/llvm-project?rev=44849&view=rev
Log:
refactor some code, no functionality change.
Modified:
llvm/trunk/lib/VMCore/ConstantFold.cpp
Modified: llvm/trunk/lib/VMCore/ConstantFold.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/ConstantFold.cpp?rev=44849&r1=44848&r2=44849&view=diff
==============================================================================
--- llvm/trunk/lib/VMCore/ConstantFold.cpp (original)
+++ llvm/trunk/lib/VMCore/ConstantFold.cpp Mon Dec 10 23:55:02 2007
@@ -138,6 +138,101 @@
Type::Int64Ty);
}
+static Constant *FoldBitCast(Constant *V, const Type *DestTy) {
+ const Type *SrcTy = V->getType();
+ if (SrcTy == DestTy)
+ return V; // no-op cast
+
+ // Check to see if we are casting a pointer to an aggregate to a pointer to
+ // the first element. If so, return the appropriate GEP instruction.
+ if (const PointerType *PTy = dyn_cast<PointerType>(V->getType()))
+ if (const PointerType *DPTy = dyn_cast<PointerType>(DestTy)) {
+ SmallVector<Value*, 8> IdxList;
+ IdxList.push_back(Constant::getNullValue(Type::Int32Ty));
+ const Type *ElTy = PTy->getElementType();
+ while (ElTy != DPTy->getElementType()) {
+ if (const StructType *STy = dyn_cast<StructType>(ElTy)) {
+ if (STy->getNumElements() == 0) break;
+ ElTy = STy->getElementType(0);
+ IdxList.push_back(Constant::getNullValue(Type::Int32Ty));
+ } else if (const SequentialType *STy = dyn_cast<SequentialType>(ElTy)) {
+ if (isa<PointerType>(ElTy)) break; // Can't index into pointers!
+ ElTy = STy->getElementType();
+ IdxList.push_back(IdxList[0]);
+ } else {
+ break;
+ }
+ }
+
+ if (ElTy == DPTy->getElementType())
+ return ConstantExpr::getGetElementPtr(V, &IdxList[0], IdxList.size());
+ }
+
+ // Handle casts from one vector constant to another. We know that the src
+ // and dest type have the same size (otherwise its an illegal cast).
+ if (const VectorType *DestPTy = dyn_cast<VectorType>(DestTy)) {
+ if (const VectorType *SrcTy = dyn_cast<VectorType>(V->getType())) {
+ assert(DestPTy->getBitWidth() == SrcTy->getBitWidth() &&
+ "Not cast between same sized vectors!");
+ // First, check for null. Undef is already handled.
+ if (isa<ConstantAggregateZero>(V))
+ return Constant::getNullValue(DestTy);
+
+ if (const ConstantVector *CV = dyn_cast<ConstantVector>(V)) {
+ // This is a cast from a ConstantVector of one type to a
+ // ConstantVector of another type. Check to see if all elements of
+ // the input are simple.
+ bool AllSimpleConstants = true;
+ for (unsigned i = 0, e = CV->getNumOperands(); i != e; ++i) {
+ if (!isa<ConstantInt>(CV->getOperand(i)) &&
+ !isa<ConstantFP>(CV->getOperand(i))) {
+ AllSimpleConstants = false;
+ break;
+ }
+ }
+
+ // If all of the elements are simple constants, we can fold this.
+ if (AllSimpleConstants)
+ return CastConstantVector(const_cast<ConstantVector*>(CV), DestPTy);
+ }
+ }
+ }
+
+ // Finally, implement bitcast folding now. The code below doesn't handle
+ // bitcast right.
+ if (isa<ConstantPointerNull>(V)) // ptr->ptr cast.
+ return ConstantPointerNull::get(cast<PointerType>(DestTy));
+
+ // Handle integral constant input.
+ if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
+ if (DestTy->isInteger())
+ // Integral -> Integral. This is a no-op because the bit widths must
+ // be the same. Consequently, we just fold to V.
+ return V;
+
+ if (DestTy->isFloatingPoint()) {
+ assert((DestTy == Type::DoubleTy || DestTy == Type::FloatTy) &&
+ "Unknown FP type!");
+ return ConstantFP::get(DestTy, APFloat(CI->getValue()));
+ }
+ // Otherwise, can't fold this (vector?)
+ return 0;
+ }
+
+ // Handle ConstantFP input.
+ if (const ConstantFP *FP = dyn_cast<ConstantFP>(V)) {
+ // FP -> Integral.
+ if (DestTy == Type::Int32Ty) {
+ return ConstantInt::get(FP->getValueAPF().convertToAPInt());
+ } else {
+ assert(DestTy == Type::Int64Ty && "only support f32/f64 for now!");
+ return ConstantInt::get(FP->getValueAPF().convertToAPInt());
+ }
+ }
+ return 0;
+}
+
+
Constant *llvm::ConstantFoldCastInstruction(unsigned opc, const Constant *V,
const Type *DestTy) {
const Type *SrcTy = V->getType();
@@ -268,100 +363,7 @@
}
return 0;
case Instruction::BitCast:
- if (SrcTy == DestTy)
- return (Constant*)V; // no-op cast
-
- // Check to see if we are casting a pointer to an aggregate to a pointer to
- // the first element. If so, return the appropriate GEP instruction.
- if (const PointerType *PTy = dyn_cast<PointerType>(V->getType()))
- if (const PointerType *DPTy = dyn_cast<PointerType>(DestTy)) {
- SmallVector<Value*, 8> IdxList;
- IdxList.push_back(Constant::getNullValue(Type::Int32Ty));
- const Type *ElTy = PTy->getElementType();
- while (ElTy != DPTy->getElementType()) {
- if (const StructType *STy = dyn_cast<StructType>(ElTy)) {
- if (STy->getNumElements() == 0) break;
- ElTy = STy->getElementType(0);
- IdxList.push_back(Constant::getNullValue(Type::Int32Ty));
- } else if (const SequentialType *STy =
- dyn_cast<SequentialType>(ElTy)) {
- if (isa<PointerType>(ElTy)) break; // Can't index into pointers!
- ElTy = STy->getElementType();
- IdxList.push_back(IdxList[0]);
- } else {
- break;
- }
- }
-
- if (ElTy == DPTy->getElementType())
- return ConstantExpr::getGetElementPtr(
- const_cast<Constant*>(V), &IdxList[0], IdxList.size());
- }
-
- // Handle casts from one vector constant to another. We know that the src
- // and dest type have the same size (otherwise its an illegal cast).
- if (const VectorType *DestPTy = dyn_cast<VectorType>(DestTy)) {
- if (const VectorType *SrcTy = dyn_cast<VectorType>(V->getType())) {
- assert(DestPTy->getBitWidth() == SrcTy->getBitWidth() &&
- "Not cast between same sized vectors!");
- // First, check for null and undef
- if (isa<ConstantAggregateZero>(V))
- return Constant::getNullValue(DestTy);
- if (isa<UndefValue>(V))
- return UndefValue::get(DestTy);
-
- if (const ConstantVector *CV = dyn_cast<ConstantVector>(V)) {
- // This is a cast from a ConstantVector of one type to a
- // ConstantVector of another type. Check to see if all elements of
- // the input are simple.
- bool AllSimpleConstants = true;
- for (unsigned i = 0, e = CV->getNumOperands(); i != e; ++i) {
- if (!isa<ConstantInt>(CV->getOperand(i)) &&
- !isa<ConstantFP>(CV->getOperand(i))) {
- AllSimpleConstants = false;
- break;
- }
- }
-
- // If all of the elements are simple constants, we can fold this.
- if (AllSimpleConstants)
- return CastConstantVector(const_cast<ConstantVector*>(CV), DestPTy);
- }
- }
- }
-
- // Finally, implement bitcast folding now. The code below doesn't handle
- // bitcast right.
- if (isa<ConstantPointerNull>(V)) // ptr->ptr cast.
- return ConstantPointerNull::get(cast<PointerType>(DestTy));
-
- // Handle integral constant input.
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
- if (DestTy->isInteger())
- // Integral -> Integral. This is a no-op because the bit widths must
- // be the same. Consequently, we just fold to V.
- return const_cast<Constant*>(V);
-
- if (DestTy->isFloatingPoint()) {
- assert((DestTy == Type::DoubleTy || DestTy == Type::FloatTy) &&
- "Unknown FP type!");
- return ConstantFP::get(DestTy, APFloat(CI->getValue()));
- }
- // Otherwise, can't fold this (vector?)
- return 0;
- }
-
- // Handle ConstantFP input.
- if (const ConstantFP *FP = dyn_cast<ConstantFP>(V)) {
- // FP -> Integral.
- if (DestTy == Type::Int32Ty) {
- return ConstantInt::get(FP->getValueAPF().convertToAPInt());
- } else {
- assert(DestTy == Type::Int64Ty && "only support f32/f64 for now!");
- return ConstantInt::get(FP->getValueAPF().convertToAPInt());
- }
- }
- return 0;
+ return FoldBitCast(const_cast<Constant*>(V), DestTy);
default:
assert(!"Invalid CE CastInst opcode");
break;
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