Refactor code to share stuff

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1127 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2001-11-04 23:24:06 +00:00
parent bacec7bc24
commit 59cd9f1e9f
4 changed files with 148 additions and 603 deletions

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@ -16,61 +16,17 @@
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/CleanupGCCOutput.h"
#include "TransformInternals.h"
#include "llvm/SymbolTable.h"
#include "llvm/DerivedTypes.h"
#include "llvm/iOther.h"
#include "llvm/iMemory.h"
#include "llvm/iTerminators.h"
#include <map>
#include <algorithm>
static const Type *PtrArrSByte = 0; // '[sbyte]*' type
static const Type *PtrSByte = 0; // 'sbyte*' type
// ReplaceInstWithValue - Replace all uses of an instruction (specified by BI)
// with a value, then remove and delete the original instruction.
//
static void ReplaceInstWithValue(BasicBlock::InstListType &BIL,
BasicBlock::iterator &BI, Value *V) {
Instruction *I = *BI;
// Replaces all of the uses of the instruction with uses of the value
I->replaceAllUsesWith(V);
// Remove the unneccesary instruction now...
BIL.remove(BI);
// Make sure to propogate a name if there is one already...
if (I->hasName() && !V->hasName())
V->setName(I->getName(), BIL.getParent()->getSymbolTable());
// Remove the dead instruction now...
delete I;
}
// ReplaceInstWithInst - Replace the instruction specified by BI with the
// instruction specified by I. The original instruction is deleted and BI is
// updated to point to the new instruction.
//
static void ReplaceInstWithInst(BasicBlock::InstListType &BIL,
BasicBlock::iterator &BI, Instruction *I) {
assert(I->getParent() == 0 &&
"ReplaceInstWithInst: Instruction already inserted into basic block!");
// Insert the new instruction into the basic block...
BI = BIL.insert(BI, I)+1;
// Replace all uses of the old instruction, and delete it.
ReplaceInstWithValue(BIL, BI, I);
// Reexamine the instruction just inserted next time around the cleanup pass
// loop.
--BI;
}
// ConvertCallTo - Convert a call to a varargs function with no arg types
// specified to a concrete nonvarargs method.
//

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@ -30,20 +30,19 @@
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/LevelChange.h"
#include "TransformInternals.h"
#include "llvm/Method.h"
#include "llvm/Support/STLExtras.h"
#include "llvm/iOther.h"
#include "llvm/iMemory.h"
#include "llvm/ConstPoolVals.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Optimizations/ConstantHandling.h"
#include "llvm/Optimizations/DCE.h"
#include <map>
#include <algorithm>
#include "llvm/Assembly/Writer.h"
//#define DEBUG_PEEPHOLE_INSTS 1
#define DEBUG_PEEPHOLE_INSTS 1
#ifdef DEBUG_PEEPHOLE_INSTS
#define PRINT_PEEPHOLE(ID, NUM, I) \
@ -60,43 +59,6 @@
PRINT_PEEPHOLE(ID, 2, I3); } while (0)
// TargetData Hack: Eventually we will have annotations given to us by the
// backend so that we know stuff about type size and alignments. For now
// though, just use this, because it happens to match the model that GCC uses.
//
const TargetData TD("LevelRaise: Should be GCC though!");
// losslessCastableTypes - Return true if the types are bitwise equivalent.
// This predicate returns true if it is possible to cast from one type to
// another without gaining or losing precision, or altering the bits in any way.
//
static bool losslessCastableTypes(const Type *T1, const Type *T2) {
if (!T1->isPrimitiveType() && !isa<PointerType>(T1)) return false;
if (!T2->isPrimitiveType() && !isa<PointerType>(T2)) return false;
if (T1->getPrimitiveID() == T2->getPrimitiveID())
return true; // Handles identity cast, and cast of differing pointer types
// Now we know that they are two differing primitive or pointer types
switch (T1->getPrimitiveID()) {
case Type::UByteTyID: return T2 == Type::SByteTy;
case Type::SByteTyID: return T2 == Type::UByteTy;
case Type::UShortTyID: return T2 == Type::ShortTy;
case Type::ShortTyID: return T2 == Type::UShortTy;
case Type::UIntTyID: return T2 == Type::IntTy;
case Type::IntTyID: return T2 == Type::UIntTy;
case Type::ULongTyID:
case Type::LongTyID:
case Type::PointerTyID:
return T2 == Type::ULongTy || T2 == Type::LongTy ||
T2->getPrimitiveID() == Type::PointerTyID;
default:
return false; // Other types have no identity values
}
}
// isReinterpretingCast - Return true if the cast instruction specified will
// cause the operand to be "reinterpreted". A value is reinterpreted if the
// cast instruction would cause the underlying bits to change.
@ -153,524 +115,6 @@ static const Type *getStructOffsetType(const Type *Ty, unsigned &Offset,
// ReplaceInstWithValue - Replace all uses of an instruction (specified by BI)
// with a value, then remove and delete the original instruction.
//
static void ReplaceInstWithValue(BasicBlock::InstListType &BIL,
BasicBlock::iterator &BI, Value *V) {
Instruction *I = *BI;
// Replaces all of the uses of the instruction with uses of the value
I->replaceAllUsesWith(V);
// Remove the unneccesary instruction now...
BIL.remove(BI);
// Make sure to propogate a name if there is one already...
if (I->hasName() && !V->hasName())
V->setName(I->getName(), BIL.getParent()->getSymbolTable());
// Remove the dead instruction now...
delete I;
}
// ReplaceInstWithInst - Replace the instruction specified by BI with the
// instruction specified by I. The original instruction is deleted and BI is
// updated to point to the new instruction.
//
static void ReplaceInstWithInst(BasicBlock::InstListType &BIL,
BasicBlock::iterator &BI, Instruction *I) {
assert(I->getParent() == 0 &&
"ReplaceInstWithInst: Instruction already inserted into basic block!");
// Insert the new instruction into the basic block...
BI = BIL.insert(BI, I)+1;
// Replace all uses of the old instruction, and delete it.
ReplaceInstWithValue(BIL, BI, I);
// Reexamine the instruction just inserted next time around the cleanup pass
// loop.
--BI;
}
typedef map<const Value*, const Type*> ValueTypeCache;
typedef map<const Value*, Value*> ValueMapCache;
// ExpressionConvertableToType - Return true if it is possible
static bool ExpressionConvertableToType(Value *V, const Type *Ty) {
Instruction *I = dyn_cast<Instruction>(V);
if (I == 0) {
// It's not an instruction, check to see if it's a constant... all constants
// can be converted to an equivalent value (except pointers, they can't be
// const prop'd in general).
//
if (isa<ConstPoolVal>(V) &&
!isa<PointerType>(V->getType()) && !isa<PointerType>(Ty)) return true;
return false; // Otherwise, we can't convert!
}
if (I->getType() == Ty) return false; // Expression already correct type!
switch (I->getOpcode()) {
case Instruction::Cast:
// We can convert the expr if the cast destination type is losslessly
// convertable to the requested type.
return losslessCastableTypes(Ty, I->getType());
case Instruction::Add:
case Instruction::Sub:
return ExpressionConvertableToType(I->getOperand(0), Ty) &&
ExpressionConvertableToType(I->getOperand(1), Ty);
case Instruction::Shr:
if (Ty->isSigned() != V->getType()->isSigned()) return false;
// FALL THROUGH
case Instruction::Shl:
return ExpressionConvertableToType(I->getOperand(0), Ty);
case Instruction::Load: {
LoadInst *LI = cast<LoadInst>(I);
if (LI->hasIndices()) return false;
return ExpressionConvertableToType(LI->getPtrOperand(),
PointerType::get(Ty));
}
case Instruction::GetElementPtr: {
// GetElementPtr's are directly convertable to a pointer type if they have
// a number of zeros at the end. Because removing these values does not
// change the logical offset of the GEP, it is okay and fair to remove them.
// This can change this:
// %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
// %t2 = cast %List * * %t1 to %List *
// into
// %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
//
GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
const PointerType *PTy = dyn_cast<PointerType>(Ty);
if (!PTy) return false;
// Check to see if there are zero elements that we can remove from the
// index array. If there are, check to see if removing them causes us to
// get to the right type...
//
vector<ConstPoolVal*> Indices = GEP->getIndices();
const Type *BaseType = GEP->getPtrOperand()->getType();
while (Indices.size() &&
cast<ConstPoolUInt>(Indices.back())->getValue() == 0) {
Indices.pop_back();
const Type *ElTy = GetElementPtrInst::getIndexedType(BaseType, Indices,
true);
if (ElTy == PTy->getValueType())
return true; // Found a match!!
}
break; // No match, maybe next time.
}
}
return false;
}
static Value *ConvertExpressionToType(Value *V, const Type *Ty) {
assert(ExpressionConvertableToType(V, Ty) && "Value is not convertable!");
Instruction *I = dyn_cast<Instruction>(V);
if (I == 0)
if (ConstPoolVal *CPV = cast<ConstPoolVal>(V)) {
// Constants are converted by constant folding the cast that is required.
// We assume here that all casts are implemented for constant prop.
Value *Result = opt::ConstantFoldCastInstruction(CPV, Ty);
if (!Result) cerr << "Couldn't fold " << CPV << " to " << Ty << endl;
assert(Result && "ConstantFoldCastInstruction Failed!!!");
return Result;
}
BasicBlock *BB = I->getParent();
BasicBlock::InstListType &BIL = BB->getInstList();
string Name = I->getName(); if (!Name.empty()) I->setName("");
Instruction *Res; // Result of conversion
//cerr << endl << endl << "Type:\t" << Ty << "\nInst: " << I << "BB Before: " << BB << endl;
switch (I->getOpcode()) {
case Instruction::Cast:
Res = new CastInst(I->getOperand(0), Ty, Name);
break;
case Instruction::Add:
case Instruction::Sub:
Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
ConvertExpressionToType(I->getOperand(0), Ty),
ConvertExpressionToType(I->getOperand(1), Ty),
Name);
break;
case Instruction::Shl:
case Instruction::Shr:
Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(),
ConvertExpressionToType(I->getOperand(0), Ty),
I->getOperand(1), Name);
break;
case Instruction::Load: {
LoadInst *LI = cast<LoadInst>(I);
assert(!LI->hasIndices());
Res = new LoadInst(ConvertExpressionToType(LI->getPtrOperand(),
PointerType::get(Ty)), Name);
break;
}
case Instruction::GetElementPtr: {
// GetElementPtr's are directly convertable to a pointer type if they have
// a number of zeros at the end. Because removing these values does not
// change the logical offset of the GEP, it is okay and fair to remove them.
// This can change this:
// %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
// %t2 = cast %List * * %t1 to %List *
// into
// %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
//
GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
// Check to see if there are zero elements that we can remove from the
// index array. If there are, check to see if removing them causes us to
// get to the right type...
//
vector<ConstPoolVal*> Indices = GEP->getIndices();
const Type *BaseType = GEP->getPtrOperand()->getType();
const Type *PVTy = cast<PointerType>(Ty)->getValueType();
Res = 0;
while (Indices.size() &&
cast<ConstPoolUInt>(Indices.back())->getValue() == 0) {
Indices.pop_back();
if (GetElementPtrInst::getIndexedType(BaseType, Indices, true) == PVTy) {
if (Indices.size() == 0) {
Res = new CastInst(GEP->getPtrOperand(), BaseType); // NOOP
} else {
Res = new GetElementPtrInst(GEP->getPtrOperand(), Indices, Name);
}
break;
}
}
assert(Res && "Didn't find match!");
break; // No match, maybe next time.
}
default:
assert(0 && "Expression convertable, but don't know how to convert?");
return 0;
}
BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
assert(It != BIL.end() && "Instruction not in own basic block??");
BIL.insert(It, Res);
//cerr << "RInst: " << Res << "BB After: " << BB << endl << endl;
return Res;
}
static inline const Type *getTy(const Value *V, ValueTypeCache &CT) {
ValueTypeCache::iterator I = CT.find(V);
if (I == CT.end()) return V->getType();
return I->second;
}
static bool OperandConvertableToType(User *U, Value *V, const Type *Ty,
ValueTypeCache &ConvertedTypes);
// RetValConvertableToType - Return true if it is possible
static bool RetValConvertableToType(Value *V, const Type *Ty,
ValueTypeCache &ConvertedTypes) {
ValueTypeCache::iterator I = ConvertedTypes.find(V);
if (I != ConvertedTypes.end()) return I->second == Ty;
ConvertedTypes[V] = Ty;
// It is safe to convert the specified value to the specified type IFF all of
// the uses of the value can be converted to accept the new typed value.
//
for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I)
if (!OperandConvertableToType(*I, V, Ty, ConvertedTypes))
return false;
return true;
}
// OperandConvertableToType - Return true if it is possible to convert operand
// V of User (instruction) U to the specified type. This is true iff it is
// possible to change the specified instruction to accept this. CTMap is a map
// of converted types, so that circular definitions will see the future type of
// the expression, not the static current type.
//
static bool OperandConvertableToType(User *U, Value *V, const Type *Ty,
ValueTypeCache &CTMap) {
assert(V->getType() != Ty &&
"OperandConvertableToType: Operand is already right type!");
Instruction *I = dyn_cast<Instruction>(U);
if (I == 0) return false; // We can't convert!
switch (I->getOpcode()) {
case Instruction::Cast:
assert(I->getOperand(0) == V);
// We can convert the expr if the cast destination type is losslessly
// convertable to the requested type.
return losslessCastableTypes(Ty, I->getOperand(0)->getType());
case Instruction::Add:
case Instruction::Sub: {
Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
return RetValConvertableToType(I, Ty, CTMap) &&
ExpressionConvertableToType(OtherOp, Ty);
}
case Instruction::SetEQ:
case Instruction::SetNE: {
Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
return ExpressionConvertableToType(OtherOp, Ty);
}
case Instruction::Shr:
if (Ty->isSigned() != V->getType()->isSigned()) return false;
// FALL THROUGH
case Instruction::Shl:
assert(I->getOperand(0) == V);
return RetValConvertableToType(I, Ty, CTMap);
case Instruction::Load:
assert(I->getOperand(0) == V);
if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
LoadInst *LI = cast<LoadInst>(I);
if (LI->hasIndices() ||
TD.getTypeSize(PT->getValueType()) != TD.getTypeSize(LI->getType()))
return false;
return RetValConvertableToType(LI, PT->getValueType(), CTMap);
}
return false;
case Instruction::Store: {
StoreInst *SI = cast<StoreInst>(I);
if (SI->hasIndices()) return false;
if (V == I->getOperand(0)) {
// Can convert the store if we can convert the pointer operand to match
// the new value type...
return ExpressionConvertableToType(I->getOperand(1),PointerType::get(Ty));
} else if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
if (isa<ArrayType>(PT->getValueType()))
return false; // Avoid getDataSize on unsized array type!
assert(V == I->getOperand(1));
// Must move the same amount of data...
if (TD.getTypeSize(PT->getValueType()) !=
TD.getTypeSize(I->getOperand(0)->getType())) return false;
// Can convert store if the incoming value is convertable...
return ExpressionConvertableToType(I->getOperand(0), PT->getValueType());
}
return false;
}
#if 0
case Instruction::GetElementPtr: {
// GetElementPtr's are directly convertable to a pointer type if they have
// a number of zeros at the end. Because removing these values does not
// change the logical offset of the GEP, it is okay and fair to remove them.
// This can change this:
// %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
// %t2 = cast %List * * %t1 to %List *
// into
// %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
//
GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
const PointerType *PTy = dyn_cast<PointerType>(Ty);
if (!PTy) return false;
// Check to see if there are zero elements that we can remove from the
// index array. If there are, check to see if removing them causes us to
// get to the right type...
//
vector<ConstPoolVal*> Indices = GEP->getIndices();
const Type *BaseType = GEP->getPtrOperand()->getType();
while (Indices.size() &&
cast<ConstPoolUInt>(Indices.back())->getValue() == 0) {
Indices.pop_back();
const Type *ElTy = GetElementPtrInst::getIndexedType(BaseType, Indices,
true);
if (ElTy == PTy->getValueType())
return true; // Found a match!!
}
break; // No match, maybe next time.
}
#endif
}
return false;
}
static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
ValueMapCache &VMC);
// RetValConvertableToType - Return true if it is possible
static void ConvertUsersType(Value *V, Value *NewVal, ValueMapCache &VMC) {
// It is safe to convert the specified value to the specified type IFF all of
// the uses of the value can be converted to accept the new typed value.
//
while (!V->use_empty()) {
unsigned OldSize = V->use_size();
ConvertOperandToType(V->use_back(), V, NewVal, VMC);
assert(V->use_size() != OldSize && "Use didn't detatch from value!");
}
}
static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
ValueMapCache &VMC) {
Instruction *I = cast<Instruction>(U); // Only Instructions convertable
BasicBlock *BB = I->getParent();
BasicBlock::InstListType &BIL = BB->getInstList();
string Name = I->getName(); if (!Name.empty()) I->setName("");
Instruction *Res; // Result of conversion
//cerr << endl << endl << "Type:\t" << Ty << "\nInst: " << I << "BB Before: " << BB << endl;
switch (I->getOpcode()) {
case Instruction::Cast:
assert(I->getOperand(0) == OldVal);
Res = new CastInst(NewVal, I->getType(), Name);
break;
case Instruction::Add:
case Instruction::Sub:
case Instruction::SetEQ:
case Instruction::SetNE: {
unsigned OtherIdx = (OldVal == I->getOperand(0)) ? 1 : 0;
Value *OtherOp = I->getOperand(OtherIdx);
Value *NewOther = ConvertExpressionToType(OtherOp, NewVal->getType());
Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
OtherIdx == 0 ? NewOther : NewVal,
OtherIdx == 1 ? NewOther : NewVal,
Name);
break;
}
case Instruction::Shl:
case Instruction::Shr:
assert(I->getOperand(0) == OldVal);
Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), NewVal,
I->getOperand(1), Name);
break;
case Instruction::Load:
assert(I->getOperand(0) == OldVal);
Res = new LoadInst(NewVal, Name);
break;
case Instruction::Store: {
if (I->getOperand(0) == OldVal) { // Replace the source value
Value *NewPtr =
ConvertExpressionToType(I->getOperand(1),
PointerType::get(NewVal->getType()));
Res = new StoreInst(NewVal, NewPtr);
} else { // Replace the source pointer
const Type *ValType =cast<PointerType>(NewVal->getType())->getValueType();
Value *NewV = ConvertExpressionToType(I->getOperand(0), ValType);
Res = new StoreInst(NewV, NewVal);
}
break;
}
#if 0
case Instruction::GetElementPtr: {
// GetElementPtr's are directly convertable to a pointer type if they have
// a number of zeros at the end. Because removing these values does not
// change the logical offset of the GEP, it is okay and fair to remove them.
// This can change this:
// %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
// %t2 = cast %List * * %t1 to %List *
// into
// %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
//
GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
// Check to see if there are zero elements that we can remove from the
// index array. If there are, check to see if removing them causes us to
// get to the right type...
//
vector<ConstPoolVal*> Indices = GEP->getIndices();
const Type *BaseType = GEP->getPtrOperand()->getType();
const Type *PVTy = cast<PointerType>(Ty)->getValueType();
Res = 0;
while (Indices.size() &&
cast<ConstPoolUInt>(Indices.back())->getValue() == 0) {
Indices.pop_back();
if (GetElementPtrInst::getIndexedType(BaseType, Indices, true) == PVTy) {
if (Indices.size() == 0) {
Res = new CastInst(GEP->getPtrOperand(), BaseType); // NOOP
} else {
Res = new GetElementPtrInst(GEP->getPtrOperand(), Indices, Name);
}
break;
}
}
assert(Res && "Didn't find match!");
break; // No match, maybe next time.
}
#endif
default:
assert(0 && "Expression convertable, but don't know how to convert?");
return;
}
BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
assert(It != BIL.end() && "Instruction not in own basic block??");
BIL.insert(It, Res); // Keep It pointing to old instruction
#if DEBUG_PEEPHOLE_INSTS
cerr << "In: " << I << "Out: " << Res;
#endif
//cerr << "RInst: " << Res << "BB After: " << BB << endl << endl;
if (I->getType() != Res->getType())
ConvertUsersType(I, Res, VMC);
else
I->replaceAllUsesWith(Res);
// Now we just need to remove the old instruction so we don't get infinite
// loops. Note that we cannot use DCE because DCE won't remove a store
// instruction, for example.
assert(I->use_size() == 0 && "Uses of Instruction remain!!!");
It = find(BIL.begin(), BIL.end(), I);
assert(It != BIL.end() && "Instruction no longer in basic block??");
delete BIL.remove(It);
}
// DoInsertArrayCast - If the argument value has a pointer type, and if the

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@ -0,0 +1,89 @@
//===-- TransformInternals.cpp - Implement shared functions for transforms --=//
//
// This file defines shared functions used by the different components of the
// Transforms library.
//
//===----------------------------------------------------------------------===//
#include "TransformInternals.h"
#include "llvm/Method.h"
#include "llvm/Type.h"
// TargetData Hack: Eventually we will have annotations given to us by the
// backend so that we know stuff about type size and alignments. For now
// though, just use this, because it happens to match the model that GCC uses.
//
const TargetData TD("LevelRaise: Should be GCC though!");
// losslessCastableTypes - Return true if the types are bitwise equivalent.
// This predicate returns true if it is possible to cast from one type to
// another without gaining or losing precision, or altering the bits in any way.
//
bool losslessCastableTypes(const Type *T1, const Type *T2) {
if (!T1->isPrimitiveType() && !T1->isPointerType()) return false;
if (!T2->isPrimitiveType() && !T2->isPointerType()) return false;
if (T1->getPrimitiveID() == T2->getPrimitiveID())
return true; // Handles identity cast, and cast of differing pointer types
// Now we know that they are two differing primitive or pointer types
switch (T1->getPrimitiveID()) {
case Type::UByteTyID: return T2 == Type::SByteTy;
case Type::SByteTyID: return T2 == Type::UByteTy;
case Type::UShortTyID: return T2 == Type::ShortTy;
case Type::ShortTyID: return T2 == Type::UShortTy;
case Type::UIntTyID: return T2 == Type::IntTy;
case Type::IntTyID: return T2 == Type::UIntTy;
case Type::ULongTyID:
case Type::LongTyID:
case Type::PointerTyID:
return T2 == Type::ULongTy || T2 == Type::LongTy ||
T2->getPrimitiveID() == Type::PointerTyID;
default:
return false; // Other types have no identity values
}
}
// ReplaceInstWithValue - Replace all uses of an instruction (specified by BI)
// with a value, then remove and delete the original instruction.
//
void ReplaceInstWithValue(BasicBlock::InstListType &BIL,
BasicBlock::iterator &BI, Value *V) {
Instruction *I = *BI;
// Replaces all of the uses of the instruction with uses of the value
I->replaceAllUsesWith(V);
// Remove the unneccesary instruction now...
BIL.remove(BI);
// Make sure to propogate a name if there is one already...
if (I->hasName() && !V->hasName())
V->setName(I->getName(), BIL.getParent()->getSymbolTable());
// Remove the dead instruction now...
delete I;
}
// ReplaceInstWithInst - Replace the instruction specified by BI with the
// instruction specified by I. The original instruction is deleted and BI is
// updated to point to the new instruction.
//
void ReplaceInstWithInst(BasicBlock::InstListType &BIL,
BasicBlock::iterator &BI, Instruction *I) {
assert(I->getParent() == 0 &&
"ReplaceInstWithInst: Instruction already inserted into basic block!");
// Insert the new instruction into the basic block...
BI = BIL.insert(BI, I)+1;
// Replace all uses of the old instruction, and delete it.
ReplaceInstWithValue(BIL, BI, I);
// Reexamine the instruction just inserted next time around the cleanup pass
// loop.
--BI;
}

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@ -0,0 +1,56 @@
//===-- TransformInternals.h - Shared functions for Transforms ---*- C++ -*--=//
//
// This header file declares shared functions used by the different components
// of the Transforms library.
//
//===----------------------------------------------------------------------===//
#ifndef TRANSFORM_INTERNALS_H
#define TRANSFORM_INTERNALS_H
#include "llvm/BasicBlock.h"
#include "llvm/Target/TargetData.h"
#include <map>
// TargetData Hack: Eventually we will have annotations given to us by the
// backend so that we know stuff about type size and alignments. For now
// though, just use this, because it happens to match the model that GCC uses.
//
// FIXME: This should use annotations
//
extern const TargetData TD;
// losslessCastableTypes - Return true if the types are bitwise equivalent.
// This predicate returns true if it is possible to cast from one type to
// another without gaining or losing precision, or altering the bits in any way.
//
bool losslessCastableTypes(const Type *T1, const Type *T2);
// ReplaceInstWithValue - Replace all uses of an instruction (specified by BI)
// with a value, then remove and delete the original instruction.
//
void ReplaceInstWithValue(BasicBlock::InstListType &BIL,
BasicBlock::iterator &BI, Value *V);
// ReplaceInstWithInst - Replace the instruction specified by BI with the
// instruction specified by I. The original instruction is deleted and BI is
// updated to point to the new instruction.
//
void ReplaceInstWithInst(BasicBlock::InstListType &BIL,
BasicBlock::iterator &BI, Instruction *I);
// ------------- Expression Conversion ---------------------
typedef map<const Value*, const Type*> ValueTypeCache;
typedef map<const Value*, Value*> ValueMapCache;
// RetValConvertableToType - Return true if it is possible
bool RetValConvertableToType(Value *V, const Type *Ty,
ValueTypeCache &ConvertedTypes);
void ConvertUsersType(Value *V, Value *NewVal, ValueMapCache &VMC);
#endif