6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-14 00:32:55 +00:00
Code Issues Projects Releases Wiki Activity

be tolerant of PHI nodes when rewriting heap SROA code. This is a step

Browse Source 
along the way of PR1639


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41930 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2007-09-13 18:00:31 +00:00
parent 330245e90b
commit a637a8b1e7
1 changed files with 50 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

76
lib/Transforms/IPO/GlobalOpt.cpp
View File

@ -844,17 +844,23 @@ static bool ValueIsOnlyUsedLocallyOrStoredToOneGlobal(Instruction *V,
static void ReplaceUsesOfMallocWithGlobal(Instruction *Alloc,
GlobalVariable *GV) {
while (!Alloc->use_empty()) {
Instruction *U = Alloc->use_back();
Instruction *U = cast<Instruction>(*Alloc->use_begin());
Instruction *InsertPt = U;
if (StoreInst *SI = dyn_cast<StoreInst>(U)) {
// If this is the store of the allocation into the global, remove it.
if (SI->getOperand(1) == GV) {
SI->eraseFromParent();
continue;
}
} else if (PHINode *PN = dyn_cast<PHINode>(U)) {
// Insert the load in the corresponding predecessor, not right before the
// PHI.
unsigned PredNo = Alloc->use_begin().getOperandNo()/2;
InsertPt = PN->getIncomingBlock(PredNo)->getTerminator();
}
// Insert a load from the global, and use it instead of the malloc.
Value *NL = new LoadInst(GV, GV->getName()+".val", U);
Value *NL = new LoadInst(GV, GV->getName()+".val", InsertPt);
U->replaceUsesOfWith(Alloc, NL);
}
}
@ -891,6 +897,20 @@ static bool GlobalLoadUsesSimpleEnoughForHeapSRA(GlobalVariable *GV) {
return true;
}
/// GetHeapSROALoad - Return the load for the specified field of the HeapSROA'd
/// value, lazily creating it on demand.
static Value *GetHeapSROALoad(LoadInst *Load, unsigned FieldNo,
const std::vector<GlobalVariable*> &FieldGlobals,
std::vector<Value *> &InsertedLoadsForPtr) {
if (InsertedLoadsForPtr.size() <= FieldNo)
InsertedLoadsForPtr.resize(FieldNo+1);
if (InsertedLoadsForPtr[FieldNo] == 0)
InsertedLoadsForPtr[FieldNo] = new LoadInst(FieldGlobals[FieldNo],
Load->getName()+".f" +
utostr(FieldNo), Load);
return InsertedLoadsForPtr[FieldNo];
}
/// RewriteHeapSROALoadUser - Given a load instruction and a value derived from
/// the load, rewrite the derived value to use the HeapSRoA'd load.
static void RewriteHeapSROALoadUser(LoadInst *Load, Instruction *LoadUser,
@ -903,8 +923,7 @@ static void RewriteHeapSROALoadUser(LoadInst *Load, Instruction *LoadUser,
// field.
Value *NPtr;
if (InsertedLoadsForPtr.empty()) {
NPtr = new LoadInst(FieldGlobals[0], Load->getName()+".f0", Load);
InsertedLoadsForPtr.push_back(Load);
NPtr = GetHeapSROALoad(Load, 0, FieldGlobals, InsertedLoadsForPtr);
} else {
NPtr = InsertedLoadsForPtr.back();
}
@ -917,30 +936,35 @@ static void RewriteHeapSROALoadUser(LoadInst *Load, Instruction *LoadUser,
return;
}
// Otherwise, this should be: 'getelementptr Ptr, Idx, uint FieldNo ...'
GetElementPtrInst *GEPI = cast<GetElementPtrInst>(LoadUser);
assert(GEPI->getNumOperands() >= 3 && isa<ConstantInt>(GEPI->getOperand(2))
&& "Unexpected GEPI!");
// Handle 'getelementptr Ptr, Idx, uint FieldNo ...'
if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(LoadUser)) {
assert(GEPI->getNumOperands() >= 3 && isa<ConstantInt>(GEPI->getOperand(2))
&& "Unexpected GEPI!");
// Load the pointer for this field.
unsigned FieldNo = cast<ConstantInt>(GEPI->getOperand(2))->getZExtValue();
if (InsertedLoadsForPtr.size() <= FieldNo)
InsertedLoadsForPtr.resize(FieldNo+1);
if (InsertedLoadsForPtr[FieldNo] == 0)
InsertedLoadsForPtr[FieldNo] = new LoadInst(FieldGlobals[FieldNo],
Load->getName()+".f" +
utostr(FieldNo), Load);
Value *NewPtr = InsertedLoadsForPtr[FieldNo];
// Load the pointer for this field.
unsigned FieldNo = cast<ConstantInt>(GEPI->getOperand(2))->getZExtValue();
Value *NewPtr = GetHeapSROALoad(Load, FieldNo,
FieldGlobals, InsertedLoadsForPtr);
// Create the new GEP idx vector.
SmallVector<Value*, 8> GEPIdx;
GEPIdx.push_back(GEPI->getOperand(1));
GEPIdx.append(GEPI->op_begin()+3, GEPI->op_end());
Value *NGEPI = new GetElementPtrInst(NewPtr, GEPIdx.begin(), GEPIdx.end(),
GEPI->getName(), GEPI);
GEPI->replaceAllUsesWith(NGEPI);
GEPI->eraseFromParent();
return;
}
// Create the new GEP idx vector.
SmallVector<Value*, 8> GEPIdx;
GEPIdx.push_back(GEPI->getOperand(1));
GEPIdx.append(GEPI->op_begin()+3, GEPI->op_end());
Value *NGEPI = new GetElementPtrInst(NewPtr, GEPIdx.begin(), GEPIdx.end(),
GEPI->getName(), GEPI);
GEPI->replaceAllUsesWith(NGEPI);
GEPI->eraseFromParent();
// Handle PHI nodes. All PHI nodes must be merging in the same values, so
// just treat them like a copy.
PHINode *PN = cast<PHINode>(LoadUser);
while (!PN->use_empty())
RewriteHeapSROALoadUser(Load, PN->use_back(),
FieldGlobals, InsertedLoadsForPtr);
PN->eraseFromParent();
}
/// RewriteUsesOfLoadForHeapSRoA - We are performing Heap SRoA on a global. Ptr