#include "TransformInternals.h"
#include "llvm/Constants.h"
#include "llvm/Instructions.h"
-#include "llvm/Analysis/Expressions.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Debug.h"
#include <algorithm>
+#include <iostream>
using namespace llvm;
static bool OperandConvertibleToType(User *U, Value *V, const Type *Ty,
static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
ValueMapCache &VMC, const TargetData &TD);
-// Peephole Malloc instructions: we take a look at the use chain of the
-// malloc instruction, and try to find out if the following conditions hold:
-// 1. The malloc is of the form: 'malloc [sbyte], uint <constant>'
-// 2. The only users of the malloc are cast & add instructions
-// 3. Of the cast instructions, there is only one destination pointer type
-// [RTy] where the size of the pointed to object is equal to the number
-// of bytes allocated.
-//
-// If these conditions hold, we convert the malloc to allocate an [RTy]
-// element. TODO: This comment is out of date WRT arrays
-//
-static bool MallocConvertibleToType(MallocInst *MI, const Type *Ty,
- ValueTypeCache &CTMap,
- const TargetData &TD) {
- if (!isa<PointerType>(Ty)) return false; // Malloc always returns pointers
-
- // Deal with the type to allocate, not the pointer type...
- Ty = cast<PointerType>(Ty)->getElementType();
- if (!Ty->isSized() || !MI->getType()->getElementType()->isSized())
- return false; // Can only alloc something with a size
-
- // Analyze the number of bytes allocated...
- ExprType Expr = ClassifyExpr(MI->getArraySize());
-
- // Get information about the base datatype being allocated, before & after
- uint64_t ReqTypeSize = TD.getTypeSize(Ty);
- if (ReqTypeSize == 0) return false;
- uint64_t OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
-
- // Must have a scale or offset to analyze it...
- if (!Expr.Offset && !Expr.Scale && OldTypeSize == 1) return false;
-
- // Get the offset and scale of the allocation...
- int64_t OffsetVal = Expr.Offset ? getConstantValue(Expr.Offset) : 0;
- int64_t ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) :(Expr.Var != 0);
-
- // The old type might not be of unit size, take old size into consideration
- // here...
- uint64_t Offset = OffsetVal * OldTypeSize;
- uint64_t Scale = ScaleVal * OldTypeSize;
-
- // In order to be successful, both the scale and the offset must be a multiple
- // of the requested data type's size.
- //
- if (Offset/ReqTypeSize*ReqTypeSize != Offset ||
- Scale/ReqTypeSize*ReqTypeSize != Scale)
- return false; // Nope.
-
- return true;
-}
-
-static Instruction *ConvertMallocToType(MallocInst *MI, const Type *Ty,
- const std::string &Name,
- ValueMapCache &VMC,
- const TargetData &TD){
- BasicBlock *BB = MI->getParent();
- BasicBlock::iterator It = BB->end();
-
- // Analyze the number of bytes allocated...
- ExprType Expr = ClassifyExpr(MI->getArraySize());
-
- const PointerType *AllocTy = cast<PointerType>(Ty);
- const Type *ElType = AllocTy->getElementType();
-
- uint64_t DataSize = TD.getTypeSize(ElType);
- uint64_t OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
-
- // Get the offset and scale coefficients that we are allocating...
- int64_t OffsetVal = (Expr.Offset ? getConstantValue(Expr.Offset) : 0);
- int64_t ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) : (Expr.Var !=0);
-
- // The old type might not be of unit size, take old size into consideration
- // here...
- unsigned Offset = OffsetVal * OldTypeSize / DataSize;
- unsigned Scale = ScaleVal * OldTypeSize / DataSize;
-
- // Locate the malloc instruction, because we may be inserting instructions
- It = MI;
-
- // If we have a scale, apply it first...
- if (Expr.Var) {
- // Expr.Var is not necessarily unsigned right now, insert a cast now.
- if (Expr.Var->getType() != Type::UIntTy)
- Expr.Var = new CastInst(Expr.Var, Type::UIntTy,
- Expr.Var->getName()+"-uint", It);
-
- if (Scale != 1)
- Expr.Var = BinaryOperator::create(Instruction::Mul, Expr.Var,
- ConstantUInt::get(Type::UIntTy, Scale),
- Expr.Var->getName()+"-scl", It);
-
- } else {
- // If we are not scaling anything, just make the offset be the "var"...
- Expr.Var = ConstantUInt::get(Type::UIntTy, Offset);
- Offset = 0; Scale = 1;
- }
-
- // If we have an offset now, add it in...
- if (Offset != 0) {
- assert(Expr.Var && "Var must be nonnull by now!");
- Expr.Var = BinaryOperator::create(Instruction::Add, Expr.Var,
- ConstantUInt::get(Type::UIntTy, Offset),
- Expr.Var->getName()+"-off", It);
- }
-
- assert(AllocTy == Ty);
- return new MallocInst(AllocTy->getElementType(), Expr.Var, Name);
-}
-
// ExpressionConvertibleToType - Return true if it is possible
bool llvm::ExpressionConvertibleToType(Value *V, const Type *Ty,
break;
}
- case Instruction::Malloc:
- if (!MallocConvertibleToType(cast<MallocInst>(I), Ty, CTMap, TD))
- return false;
- break;
-
case Instruction::GetElementPtr: {
// GetElementPtr's are directly convertible to a pointer type if they have
// a number of zeros at the end. Because removing these values does not
ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(V);
if (VMCI != VMC.ExprMap.end()) {
- const Value *GV = VMCI->second;
- const Type *GTy = VMCI->second->getType();
assert(VMCI->second->getType() == Ty);
if (Instruction *I = dyn_cast<Instruction>(V))
break;
}
- case Instruction::Malloc: {
- Res = ConvertMallocToType(cast<MallocInst>(I), Ty, Name, VMC, TD);
- break;
- }
-
case Instruction::GetElementPtr: {
// GetElementPtr's are directly convertible to a pointer type if they have
// a number of zeros at the end. Because removing these values does not
return false;
case Instruction::Store: {
- StoreInst *SI = cast<StoreInst>(I);
-
if (V == I->getOperand(0)) {
ValueTypeCache::iterator CTMI = CTMap.find(I->getOperand(1));
if (CTMI != CTMap.end()) { // Operand #1 is in the table already?
projects / oota-llvm.git / blobdiff