6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-03-03 14:31:10 +00:00
Code Issues Projects Releases Wiki Activity

Code cleanups

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2391 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2002-04-29 01:22:55 +00:00
parent 18b24ea4b6
commit 2f6f03bddd
1 changed files with 114 additions and 130 deletions

244
lib/Transforms/Scalar/DecomposeMultiDimRefs.cpp

@ -1,4 +1,4 @@
//===- llvm/Transforms/DecomposeMultiDimRefs.cpp - Lower array refs to 1D ---=//
//===- llvm/Transforms/DecomposeMultiDimRefs.cpp - Lower array refs to 1D -===//
//
// DecomposeMultiDimRefs -
// Convert multi-dimensional references consisting of any combination
@ -17,6 +17,41 @@
#include "llvm/Function.h"
#include "llvm/Pass.h"
namespace {
struct DecomposePass : public BasicBlockPass {
virtual bool runOnBasicBlock(BasicBlock *BB);
private:
static void decomposeArrayRef(BasicBlock::iterator &BBI);
};
}
Pass *createDecomposeMultiDimRefsPass() {
return new DecomposePass();
}
// runOnBasicBlock - Entry point for array or structure references with multiple
// indices.
//
bool DecomposePass::runOnBasicBlock(BasicBlock *BB) {
bool Changed = false;
for (BasicBlock::iterator II = BB->begin(); II != BB->end(); ) {
if (MemAccessInst *MAI = dyn_cast<MemAccessInst>(*II)) {
if (MAI->getNumOperands() > MAI->getFirstIndexOperandNumber()+1) {
decomposeArrayRef(II);
Changed = true;
} else {
++II;
}
} else {
++II;
}
}
return Changed;
}
//
// For any combination of 2 or more array and structure indices,
@ -28,160 +63,109 @@
// uses the last ptr2 generated in the loop and a single index.
// If any index is (uint) 0, we omit the getElementPtr instruction.
//
static BasicBlock::iterator
decomposeArrayRef(BasicBlock::iterator& BBI)
{
void DecomposePass::decomposeArrayRef(BasicBlock::iterator &BBI){
MemAccessInst *memI = cast<MemAccessInst>(*BBI);
BasicBlock* BB = memI->getParent();
Value* lastPtr = memI->getPointerOperand();
// Remove the instruction from the stream
BB->getInstList().remove(BBI);
vector<Instruction*> newIvec;
// Process each index except the last one.
//
MemAccessInst::const_op_iterator OI = memI->idx_begin();
MemAccessInst::const_op_iterator OE = memI->idx_end();
for ( ; OI != OE; ++OI)
{
assert(isa<PointerType>(lastPtr->getType()));
User::const_op_iterator OI = memI->idx_begin(), OE = memI->idx_end();
for (; OI != OE && OI+1 != OE; ++OI) {
assert(isa<PointerType>(lastPtr->getType()));
if (OI+1 == OE) // stop before the last operand
break;
// Check for a zero index. This will need a cast instead of
// a getElementPtr, or it may need neither.
bool indexIsZero = isa<ConstantUInt>(*OI) &&
cast<Constant>(*OI)->isNullValue();
// Check for a zero index. This will need a cast instead of
// a getElementPtr, or it may need neither.
bool indexIsZero = bool(isa<ConstantUInt>(*OI) &&
cast<ConstantUInt>(*OI)->getValue() == 0);
// Extract the first index. If the ptr is a pointer to a structure
// and the next index is a structure offset (i.e., not an array offset),
// we need to include an initial [0] to index into the pointer.
vector<Value*> idxVec(1, *OI);
PointerType* ptrType = cast<PointerType>(lastPtr->getType());
if (isa<StructType>(ptrType->getElementType())
&& ! ptrType->indexValid(*OI))
idxVec.insert(idxVec.begin(), ConstantUInt::get(Type::UIntTy, 0));
// Get the type obtained by applying the first index.
// It must be a structure or array.
const Type* nextType = MemAccessInst::getIndexedType(lastPtr->getType(),
idxVec, true);
assert(isa<StructType>(nextType) || isa<ArrayType>(nextType));
// Get a pointer to the structure or to the elements of the array.
const Type* nextPtrType =
PointerType::get(isa<StructType>(nextType) ? nextType
: cast<ArrayType>(nextType)->getElementType());
// Extract the first index. If the ptr is a pointer to a structure
// and the next index is a structure offset (i.e., not an array offset),
// we need to include an initial [0] to index into the pointer.
vector<Value*> idxVec(1, *OI);
PointerType* ptrType = cast<PointerType>(lastPtr->getType());
if (isa<StructType>(ptrType->getElementType())
&& ! ptrType->indexValid(*OI))
idxVec.insert(idxVec.begin(), ConstantUInt::get(Type::UIntTy, 0));
// Get the type obtained by applying the first index.
// It must be a structure or array.
const Type* nextType = MemAccessInst::getIndexedType(lastPtr->getType(),
idxVec, true);
assert(isa<StructType>(nextType) || isa<ArrayType>(nextType));
// Get a pointer to the structure or to the elements of the array.
const Type* nextPtrType =
PointerType::get(isa<StructType>(nextType)? nextType
: cast<ArrayType>(nextType)->getElementType());
// Instruction 1: nextPtr1 = GetElementPtr lastPtr, idxVec
// This is not needed if the index is zero.
Value* gepValue;
if (indexIsZero)
gepValue = lastPtr;
else
{
gepValue = new GetElementPtrInst(lastPtr, idxVec,"ptr1");
newIvec.push_back(cast<Instruction>(gepValue));
}
// Instruction 2: nextPtr2 = cast nextPtr1 to nextPtrType
// This is not needed if the two types are identical.
Value* castInst;
if (gepValue->getType() == nextPtrType)
castInst = gepValue;
else
{
castInst = new CastInst(gepValue, nextPtrType, "ptr2");
newIvec.push_back(cast<Instruction>(castInst));
}
lastPtr = castInst;
// Instruction 1: nextPtr1 = GetElementPtr lastPtr, idxVec
// This is not needed if the index is zero.
Value *gepValue;
if (indexIsZero)
gepValue = lastPtr;
else {
gepValue = new GetElementPtrInst(lastPtr, idxVec,"ptr1");
newIvec.push_back(cast<Instruction>(gepValue));
}
// Instruction 2: nextPtr2 = cast nextPtr1 to nextPtrType
// This is not needed if the two types are identical.
Value *castInst;
if (gepValue->getType() == nextPtrType)
castInst = gepValue;
else {
castInst = new CastInst(gepValue, nextPtrType, "ptr2");
newIvec.push_back(cast<Instruction>(castInst));
}
lastPtr = castInst;
}
//
// Now create a new instruction to replace the original one
//
PointerType* ptrType = cast<PointerType>(lastPtr->getType());
assert(ptrType);
PointerType *ptrType = cast<PointerType>(lastPtr->getType());
// First, get the final index vector. As above, we may need an initial [0].
vector<Value*> idxVec(1, *OI);
if (isa<StructType>(ptrType->getElementType())
&& ! ptrType->indexValid(*OI))
idxVec.insert(idxVec.begin(), ConstantUInt::get(Type::UIntTy, 0));
&& !ptrType->indexValid(*OI))
idxVec.insert(idxVec.begin(), Constant::getNullValue(Type::UIntTy));
const std::string newInstName = memI->hasName()? memI->getName()
: string("finalRef");
Instruction* newInst = NULL;
switch(memI->getOpcode())
{
case Instruction::Load:
newInst = new LoadInst(lastPtr, idxVec /*, newInstName */); break;
case Instruction::Store:
newInst = new StoreInst(memI->getOperand(0),
lastPtr, idxVec /*, newInstName */); break;
break;
case Instruction::GetElementPtr:
newInst = new GetElementPtrInst(lastPtr, idxVec /*, newInstName */); break;
default:
assert(0 && "Unrecognized memory access instruction"); break;
}
switch(memI->getOpcode()) {
case Instruction::Load:
newInst = new LoadInst(lastPtr, idxVec, memI->getName());
break;
case Instruction::Store:
newInst = new StoreInst(memI->getOperand(0), lastPtr, idxVec);
break;
case Instruction::GetElementPtr:
newInst = new GetElementPtrInst(lastPtr, idxVec, memI->getName());
break;
default:
assert(0 && "Unrecognized memory access instruction");
}
newIvec.push_back(newInst);
// Replace all uses of the old instruction with the new
memI->replaceAllUsesWith(newInst);
BasicBlock::iterator newI = BBI;;
for (int i = newIvec.size()-1; i >= 0; i--)
newI = BB->getInstList().insert(newI, newIvec[i]);
// Now delete the old instruction and return a pointer to the last new one
BB->getInstList().remove(memI);
// Now delete the old instruction...
delete memI;
// Convert our iterator into an index... that cannot get invalidated
unsigned ItOffs = BBI-BB->begin();
// Insert all of the new instructions...
BB->getInstList().insert(BBI, newIvec.begin(), newIvec.end());
return newI + newIvec.size() - 1; // pointer to last new instr
}
//---------------------------------------------------------------------------
// Entry point for array or structure references with multiple indices.
//---------------------------------------------------------------------------
static bool
doDecomposeMultiDimRefs(Function *F)
{
bool changed = false;
for (Function::iterator BI = F->begin(), BE = F->end(); BI != BE; ++BI)
for (BasicBlock::iterator newI, II = (*BI)->begin();
II != (*BI)->end(); II = ++newI)
{
newI = II;
if (MemAccessInst *memI = dyn_cast<MemAccessInst>(*II))
if (memI->getNumOperands() > 1 + memI->getFirstIndexOperandNumber())
{
newI = decomposeArrayRef(II);
changed = true;
}
}
return changed;
}
namespace {
struct DecomposeMultiDimRefsPass : public FunctionPass {
virtual bool runOnFunction(Function *F) {
return doDecomposeMultiDimRefs(F);
}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.preservesCFG();
}
};
}
Pass *createDecomposeMultiDimRefsPass() {
return new DecomposeMultiDimRefsPass();
// Advance the iterator to the instruction following the one just inserted...
BBI = BB->begin() + (ItOffs+newIvec.size());
}