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-rw-r--r--lib/VMCore/ConstantFold.cpp159
1 files changed, 111 insertions, 48 deletions
diff --git a/lib/VMCore/ConstantFold.cpp b/lib/VMCore/ConstantFold.cpp
index 9a91daf..573efb7 100644
--- a/lib/VMCore/ConstantFold.cpp
+++ b/lib/VMCore/ConstantFold.cpp
@@ -42,6 +42,10 @@ using namespace llvm;
/// input vector constant are all simple integer or FP values.
static Constant *BitCastConstantVector(ConstantVector *CV,
const VectorType *DstTy) {
+
+ if (CV->isAllOnesValue()) return Constant::getAllOnesValue(DstTy);
+ if (CV->isNullValue()) return Constant::getNullValue(DstTy);
+
// If this cast changes element count then we can't handle it here:
// doing so requires endianness information. This should be handled by
// Analysis/ConstantFolding.cpp
@@ -145,7 +149,7 @@ static Constant *FoldBitCast(Constant *V, const Type *DestTy) {
// This allows for other simplifications (although some of them
// can only be handled by Analysis/ConstantFolding.cpp).
if (isa<ConstantInt>(V) || isa<ConstantFP>(V))
- return ConstantExpr::getBitCast(ConstantVector::get(&V, 1), DestPTy);
+ return ConstantExpr::getBitCast(ConstantVector::get(V), DestPTy);
}
// Finally, implement bitcast folding now. The code below doesn't handle
@@ -202,7 +206,7 @@ static Constant *ExtractConstantBytes(Constant *C, unsigned ByteStart,
APInt V = CI->getValue();
if (ByteStart)
V = V.lshr(ByteStart*8);
- V.trunc(ByteSize*8);
+ V = V.trunc(ByteSize*8);
return ConstantInt::get(CI->getContext(), V);
}
@@ -511,10 +515,14 @@ Constant *llvm::ConstantFoldCastInstruction(unsigned opc, Constant *V,
return Constant::getNullValue(DestTy);
return UndefValue::get(DestTy);
}
+
// No compile-time operations on this type yet.
if (V->getType()->isPPC_FP128Ty() || DestTy->isPPC_FP128Ty())
return 0;
+ if (V->isNullValue() && !DestTy->isX86_MMXTy())
+ return Constant::getNullValue(DestTy);
+
// If the cast operand is a constant expression, there's a few things we can
// do to try to simplify it.
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
@@ -637,9 +645,7 @@ Constant *llvm::ConstantFoldCastInstruction(unsigned opc, Constant *V,
case Instruction::SIToFP:
if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
APInt api = CI->getValue();
- const uint64_t zero[] = {0, 0};
- APFloat apf = APFloat(APInt(DestTy->getPrimitiveSizeInBits(),
- 2, zero));
+ APFloat apf(APInt::getNullValue(DestTy->getPrimitiveSizeInBits()), true);
(void)apf.convertFromAPInt(api,
opc==Instruction::SIToFP,
APFloat::rmNearestTiesToEven);
@@ -649,25 +655,22 @@ Constant *llvm::ConstantFoldCastInstruction(unsigned opc, Constant *V,
case Instruction::ZExt:
if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
uint32_t BitWidth = cast<IntegerType>(DestTy)->getBitWidth();
- APInt Result(CI->getValue());
- Result.zext(BitWidth);
- return ConstantInt::get(V->getContext(), Result);
+ return ConstantInt::get(V->getContext(),
+ CI->getValue().zext(BitWidth));
}
return 0;
case Instruction::SExt:
if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
uint32_t BitWidth = cast<IntegerType>(DestTy)->getBitWidth();
- APInt Result(CI->getValue());
- Result.sext(BitWidth);
- return ConstantInt::get(V->getContext(), Result);
+ return ConstantInt::get(V->getContext(),
+ CI->getValue().sext(BitWidth));
}
return 0;
case Instruction::Trunc: {
uint32_t DestBitWidth = cast<IntegerType>(DestTy)->getBitWidth();
if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
- APInt Result(CI->getValue());
- Result.trunc(DestBitWidth);
- return ConstantInt::get(V->getContext(), Result);
+ return ConstantInt::get(V->getContext(),
+ CI->getValue().trunc(DestBitWidth));
}
// The input must be a constantexpr. See if we can simplify this based on
@@ -690,10 +693,58 @@ Constant *llvm::ConstantFoldSelectInstruction(Constant *Cond,
if (ConstantInt *CB = dyn_cast<ConstantInt>(Cond))
return CB->getZExtValue() ? V1 : V2;
+ // Check for zero aggregate and ConstantVector of zeros
+ if (Cond->isNullValue()) return V2;
+
+ if (ConstantVector* CondV = dyn_cast<ConstantVector>(Cond)) {
+
+ if (CondV->isAllOnesValue()) return V1;
+
+ const VectorType *VTy = cast<VectorType>(V1->getType());
+ ConstantVector *CP1 = dyn_cast<ConstantVector>(V1);
+ ConstantVector *CP2 = dyn_cast<ConstantVector>(V2);
+
+ if ((CP1 || isa<ConstantAggregateZero>(V1)) &&
+ (CP2 || isa<ConstantAggregateZero>(V2))) {
+
+ // Find the element type of the returned vector
+ const Type *EltTy = VTy->getElementType();
+ unsigned NumElem = VTy->getNumElements();
+ std::vector<Constant*> Res(NumElem);
+
+ bool Valid = true;
+ for (unsigned i = 0; i < NumElem; ++i) {
+ ConstantInt* c = dyn_cast<ConstantInt>(CondV->getOperand(i));
+ if (!c) {
+ Valid = false;
+ break;
+ }
+ Constant *C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ Constant *C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res[i] = c->getZExtValue() ? C1 : C2;
+ }
+ // If we were able to build the vector, return it
+ if (Valid) return ConstantVector::get(Res);
+ }
+ }
+
+
if (isa<UndefValue>(V1)) return V2;
if (isa<UndefValue>(V2)) return V1;
if (isa<UndefValue>(Cond)) return V1;
if (V1 == V2) return V1;
+
+ if (ConstantExpr *TrueVal = dyn_cast<ConstantExpr>(V1)) {
+ if (TrueVal->getOpcode() == Instruction::Select)
+ if (TrueVal->getOperand(0) == Cond)
+ return ConstantExpr::getSelect(Cond, TrueVal->getOperand(1), V2);
+ }
+ if (ConstantExpr *FalseVal = dyn_cast<ConstantExpr>(V2)) {
+ if (FalseVal->getOpcode() == Instruction::Select)
+ if (FalseVal->getOperand(0) == Cond)
+ return ConstantExpr::getSelect(Cond, V1, FalseVal->getOperand(2));
+ }
+
return 0;
}
@@ -821,7 +872,7 @@ Constant *llvm::ConstantFoldShuffleVectorInstruction(Constant *V1,
Result.push_back(InElt);
}
- return ConstantVector::get(&Result[0], Result.size());
+ return ConstantVector::get(Result);
}
Constant *llvm::ConstantFoldExtractValueInstruction(Constant *Agg,
@@ -982,8 +1033,8 @@ Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode,
return Constant::getNullValue(C1->getType()); // X lshr undef -> 0
// undef lshr X -> 0
case Instruction::AShr:
- if (!isa<UndefValue>(C2))
- return C1; // undef ashr X --> undef
+ if (!isa<UndefValue>(C2)) // undef ashr X --> all ones
+ return Constant::getAllOnesValue(C1->getType());
else if (isa<UndefValue>(C1))
return C1; // undef ashr undef -> undef
else
@@ -1343,8 +1394,7 @@ Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode,
// Given ((a + b) + c), if (b + c) folds to something interesting, return
// (a + (b + c)).
- if (Instruction::isAssociative(Opcode, C1->getType()) &&
- CE1->getOpcode() == Opcode) {
+ if (Instruction::isAssociative(Opcode) && CE1->getOpcode() == Opcode) {
Constant *T = ConstantExpr::get(Opcode, CE1->getOperand(1), C2);
if (!isa<ConstantExpr>(T) || cast<ConstantExpr>(T)->getOpcode() != Opcode)
return ConstantExpr::get(Opcode, CE1->getOperand(0), T);
@@ -1413,7 +1463,7 @@ static bool isMaybeZeroSizedType(const Type *Ty) {
/// first is less than the second, return -1, if the second is less than the
/// first, return 1. If the constants are not integral, return -2.
///
-static int IdxCompare(Constant *C1, Constant *C2, const Type *ElTy) {
+static int IdxCompare(Constant *C1, Constant *C2, const Type *ElTy) {
if (C1 == C2) return 0;
// Ok, we found a different index. If they are not ConstantInt, we can't do
@@ -1896,11 +1946,11 @@ Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred,
// If we can constant fold the comparison of each element, constant fold
// the whole vector comparison.
SmallVector<Constant*, 4> ResElts;
- for (unsigned i = 0, e = C1Elts.size(); i != e; ++i) {
- // Compare the elements, producing an i1 result or constant expr.
+ // Compare the elements, producing an i1 result or constant expr.
+ for (unsigned i = 0, e = C1Elts.size(); i != e; ++i)
ResElts.push_back(ConstantExpr::getCompare(pred, C1Elts[i], C2Elts[i]));
- }
- return ConstantVector::get(&ResElts[0], ResElts.size());
+
+ return ConstantVector::get(ResElts);
}
if (C1->getType()->isFloatingPointTy()) {
@@ -1948,7 +1998,7 @@ Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred,
else if (pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT)
Result = 1;
break;
- case ICmpInst::ICMP_NE: // We know that C1 != C2
+ case FCmpInst::FCMP_ONE: // We know that C1 != C2
// We can only partially decide this relation.
if (pred == FCmpInst::FCMP_OEQ || pred == FCmpInst::FCMP_UEQ)
Result = 0;
@@ -2073,56 +2123,55 @@ Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred,
/// isInBoundsIndices - Test whether the given sequence of *normalized* indices
/// is "inbounds".
-static bool isInBoundsIndices(Constant *const *Idxs, size_t NumIdx) {
+template<typename IndexTy>
+static bool isInBoundsIndices(IndexTy const *Idxs, size_t NumIdx) {
// No indices means nothing that could be out of bounds.
if (NumIdx == 0) return true;
// If the first index is zero, it's in bounds.
- if (Idxs[0]->isNullValue()) return true;
+ if (cast<Constant>(Idxs[0])->isNullValue()) return true;
// If the first index is one and all the rest are zero, it's in bounds,
// by the one-past-the-end rule.
if (!cast<ConstantInt>(Idxs[0])->isOne())
return false;
for (unsigned i = 1, e = NumIdx; i != e; ++i)
- if (!Idxs[i]->isNullValue())
+ if (!cast<Constant>(Idxs[i])->isNullValue())
return false;
return true;
}
-Constant *llvm::ConstantFoldGetElementPtr(Constant *C,
- bool inBounds,
- Constant* const *Idxs,
- unsigned NumIdx) {
+template<typename IndexTy>
+static Constant *ConstantFoldGetElementPtrImpl(Constant *C,
+ bool inBounds,
+ IndexTy const *Idxs,
+ unsigned NumIdx) {
+ Constant *Idx0 = cast<Constant>(Idxs[0]);
if (NumIdx == 0 ||
- (NumIdx == 1 && Idxs[0]->isNullValue()))
+ (NumIdx == 1 && Idx0->isNullValue()))
return C;
if (isa<UndefValue>(C)) {
const PointerType *Ptr = cast<PointerType>(C->getType());
- const Type *Ty = GetElementPtrInst::getIndexedType(Ptr,
- (Value **)Idxs,
- (Value **)Idxs+NumIdx);
+ const Type *Ty = GetElementPtrInst::getIndexedType(Ptr, Idxs, Idxs+NumIdx);
assert(Ty != 0 && "Invalid indices for GEP!");
return UndefValue::get(PointerType::get(Ty, Ptr->getAddressSpace()));
}
- Constant *Idx0 = Idxs[0];
if (C->isNullValue()) {
bool isNull = true;
for (unsigned i = 0, e = NumIdx; i != e; ++i)
- if (!Idxs[i]->isNullValue()) {
+ if (!cast<Constant>(Idxs[i])->isNullValue()) {
isNull = false;
break;
}
if (isNull) {
const PointerType *Ptr = cast<PointerType>(C->getType());
- const Type *Ty = GetElementPtrInst::getIndexedType(Ptr,
- (Value**)Idxs,
- (Value**)Idxs+NumIdx);
+ const Type *Ty = GetElementPtrInst::getIndexedType(Ptr, Idxs,
+ Idxs+NumIdx);
assert(Ty != 0 && "Invalid indices for GEP!");
- return ConstantPointerNull::get(
- PointerType::get(Ty,Ptr->getAddressSpace()));
+ return ConstantPointerNull::get(PointerType::get(Ty,
+ Ptr->getAddressSpace()));
}
}
@@ -2173,9 +2222,9 @@ Constant *llvm::ConstantFoldGetElementPtr(Constant *C,
}
// Implement folding of:
- // int* getelementptr ([2 x int]* bitcast ([3 x int]* %X to [2 x int]*),
- // long 0, long 0)
- // To: int* getelementptr ([3 x int]* %X, long 0, long 0)
+ // i32* getelementptr ([2 x i32]* bitcast ([3 x i32]* %X to [2 x i32]*),
+ // i64 0, i64 0)
+ // To: i32* getelementptr ([3 x i32]* %X, i64 0, i64 0)
//
if (CE->isCast() && NumIdx > 1 && Idx0->isNullValue()) {
if (const PointerType *SPT =
@@ -2214,7 +2263,7 @@ Constant *llvm::ConstantFoldGetElementPtr(Constant *C,
ATy->getNumElements());
NewIdxs[i] = ConstantExpr::getSRem(CI, Factor);
- Constant *PrevIdx = Idxs[i-1];
+ Constant *PrevIdx = cast<Constant>(Idxs[i-1]);
Constant *Div = ConstantExpr::getSDiv(CI, Factor);
// Before adding, extend both operands to i64 to avoid
@@ -2242,7 +2291,7 @@ Constant *llvm::ConstantFoldGetElementPtr(Constant *C,
// If we did any factoring, start over with the adjusted indices.
if (!NewIdxs.empty()) {
for (unsigned i = 0; i != NumIdx; ++i)
- if (!NewIdxs[i]) NewIdxs[i] = Idxs[i];
+ if (!NewIdxs[i]) NewIdxs[i] = cast<Constant>(Idxs[i]);
return inBounds ?
ConstantExpr::getInBoundsGetElementPtr(C, NewIdxs.data(),
NewIdxs.size()) :
@@ -2257,3 +2306,17 @@ Constant *llvm::ConstantFoldGetElementPtr(Constant *C,
return 0;
}
+
+Constant *llvm::ConstantFoldGetElementPtr(Constant *C,
+ bool inBounds,
+ Constant* const *Idxs,
+ unsigned NumIdx) {
+ return ConstantFoldGetElementPtrImpl(C, inBounds, Idxs, NumIdx);
+}
+
+Constant *llvm::ConstantFoldGetElementPtr(Constant *C,
+ bool inBounds,
+ Value* const *Idxs,
+ unsigned NumIdx) {
+ return ConstantFoldGetElementPtrImpl(C, inBounds, Idxs, NumIdx);
+}
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