RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-12-27 14:07:32 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Turn IVChain into a struct.

Browse Source 
No functional change intended.

llvm-svn: 155675
This commit is contained in:
Jakob Stoklund Olesen 2012-04-26 23:33:09 +00:00
parent f3d4646377
commit 613b89fecd
1 changed files with 42 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

61
lib/Transforms/Scalar/LoopStrengthReduce.cpp
View File

@ -1439,7 +1439,29 @@ struct IVInc {
// IVChain - The list of IV increments in program order.
// We typically add the head of a chain without finding subsequent links.
typedef SmallVector<IVInc,1> IVChain;
struct IVChain {
SmallVector<IVInc,1> Incs;
typedef SmallVectorImpl<IVInc>::const_iterator const_iterator;
// begin - return the first increment in the chain.
const_iterator begin() const {
assert(!Incs.empty());
return llvm::next(Incs.begin());
}
const_iterator end() const {
return Incs.end();
}
// hasIncs - Returns true if this chain contains any increments.
bool hasIncs() const { return Incs.size() >= 2; }
// add - Add an IVInc to the end of this chain.
void add(const IVInc &X) { Incs.push_back(X); }
// tailUserInst - Returns the last UserInst in the chain.
Instruction *tailUserInst() const { return Incs.back().UserInst; }
};
/// ChainUsers - Helper for CollectChains to track multiple IV increment uses.
/// Distinguish between FarUsers that definitely cross IV increments and
@ -2344,7 +2366,7 @@ getProfitableChainIncrement(Value *NextIV, Value *PrevIV,
// Do not replace a constant offset from IV head with a nonconstant IV
// increment.
if (!isa<SCEVConstant>(IncExpr)) {
const SCEV *HeadExpr = SE.getSCEV(getWideOperand(Chain[0].IVOperand));
const SCEV *HeadExpr = SE.getSCEV(getWideOperand(Chain.Incs[0].IVOperand));
if (isa<SCEVConstant>(SE.getMinusSCEV(OperExpr, HeadExpr)))
return 0;
}
@ -2372,18 +2394,18 @@ isProfitableChain(IVChain &Chain, SmallPtrSet<Instruction*, 4> &Users,
if (StressIVChain)
return true;
if (Chain.size() <= 2)
if (!Chain.hasIncs())
return false;
if (!Users.empty()) {
DEBUG(dbgs() << "Chain: " << *Chain[0].UserInst << " users:\n";
DEBUG(dbgs() << "Chain: " << *Chain.Incs[0].UserInst << " users:\n";
for (SmallPtrSet<Instruction*, 4>::const_iterator I = Users.begin(),
E = Users.end(); I != E; ++I) {
dbgs() << " " << **I << "\n";
});
return false;
}
assert(!Chain.empty() && "empty IV chains are not allowed");
assert(!Chain.Incs.empty() && "empty IV chains are not allowed");
// The chain itself may require a register, so intialize cost to 1.
int cost = 1;
@ -2391,15 +2413,15 @@ isProfitableChain(IVChain &Chain, SmallPtrSet<Instruction*, 4> &Users,
// A complete chain likely eliminates the need for keeping the original IV in
// a register. LSR does not currently know how to form a complete chain unless
// the header phi already exists.
if (isa<PHINode>(Chain.back().UserInst)
&& SE.getSCEV(Chain.back().UserInst) == Chain[0].IncExpr) {
if (isa<PHINode>(Chain.tailUserInst())
&& SE.getSCEV(Chain.tailUserInst()) == Chain.Incs[0].IncExpr) {
--cost;
}
const SCEV *LastIncExpr = 0;
unsigned NumConstIncrements = 0;
unsigned NumVarIncrements = 0;
unsigned NumReusedIncrements = 0;
for (IVChain::const_iterator I = llvm::next(Chain.begin()), E = Chain.end();
for (IVChain::const_iterator I = Chain.begin(), E = Chain.end();
I != E; ++I) {
if (I->IncExpr->isZero())
@ -2435,7 +2457,8 @@ isProfitableChain(IVChain &Chain, SmallPtrSet<Instruction*, 4> &Users,
// the stride.
cost -= NumReusedIncrements;
DEBUG(dbgs() << "Chain: " << *Chain[0].UserInst << " Cost: " << cost << "\n");
DEBUG(dbgs() << "Chain: " << *Chain.Incs[0].UserInst << " Cost: " << cost
<< "\n");
return cost < 0;
}
@ -2453,13 +2476,13 @@ void LSRInstance::ChainInstruction(Instruction *UserInst, Instruction *IVOper,
unsigned ChainIdx = 0, NChains = IVChainVec.size();
const SCEV *LastIncExpr = 0;
for (; ChainIdx < NChains; ++ChainIdx) {
Value *PrevIV = getWideOperand(IVChainVec[ChainIdx].back().IVOperand);
Value *PrevIV = getWideOperand(IVChainVec[ChainIdx].Incs.back().IVOperand);
if (!isCompatibleIVType(PrevIV, NextIV))
continue;
// A phi node terminates a chain.
if (isa<PHINode>(UserInst)
&& isa<PHINode>(IVChainVec[ChainIdx].back().UserInst))
&& isa<PHINode>(IVChainVec[ChainIdx].tailUserInst()))
continue;
if (const SCEV *IncExpr =
@ -2495,7 +2518,7 @@ void LSRInstance::ChainInstruction(Instruction *UserInst, Instruction *IVOper,
<< ") IV+" << *LastIncExpr << "\n");
// Add this IV user to the end of the chain.
IVChainVec[ChainIdx].push_back(IVInc(UserInst, IVOper, LastIncExpr));
IVChainVec[ChainIdx].add(IVInc(UserInst, IVOper, LastIncExpr));
SmallPtrSet<Instruction*,4> &NearUsers = ChainUsersVec[ChainIdx].NearUsers;
// This chain's NearUsers become FarUsers.
@ -2623,10 +2646,10 @@ void LSRInstance::CollectChains() {
}
void LSRInstance::FinalizeChain(IVChain &Chain) {
assert(!Chain.empty() && "empty IV chains are not allowed");
DEBUG(dbgs() << "Final Chain: " << *Chain[0].UserInst << "\n");
assert(!Chain.Incs.empty() && "empty IV chains are not allowed");
DEBUG(dbgs() << "Final Chain: " << *Chain.Incs[0].UserInst << "\n");
for (IVChain::const_iterator I = llvm::next(Chain.begin()), E = Chain.end();
for (IVChain::const_iterator I = Chain.begin(), E = Chain.end();
I != E; ++I) {
DEBUG(dbgs() << " Inc: " << *I->UserInst << "\n");
User::op_iterator UseI =
@ -2660,7 +2683,7 @@ void LSRInstance::GenerateIVChain(const IVChain &Chain, SCEVExpander &Rewriter,
SmallVectorImpl<WeakVH> &DeadInsts) {
// Find the new IVOperand for the head of the chain. It may have been replaced
// by LSR.
const IVInc &Head = Chain[0];
const IVInc &Head = Chain.Incs[0];
User::op_iterator IVOpEnd = Head.UserInst->op_end();
User::op_iterator IVOpIter = findIVOperand(Head.UserInst->op_begin(),
IVOpEnd, L, SE);
@ -2692,7 +2715,7 @@ void LSRInstance::GenerateIVChain(const IVChain &Chain, SCEVExpander &Rewriter,
Type *IVTy = IVSrc->getType();
Type *IntTy = SE.getEffectiveSCEVType(IVTy);
const SCEV *LeftOverExpr = 0;
for (IVChain::const_iterator IncI = llvm::next(Chain.begin()),
for (IVChain::const_iterator IncI = Chain.begin(),
IncE = Chain.end(); IncI != IncE; ++IncI) {
Instruction *InsertPt = IncI->UserInst;
@ -2737,7 +2760,7 @@ void LSRInstance::GenerateIVChain(const IVChain &Chain, SCEVExpander &Rewriter,
}
// If LSR created a new, wider phi, we may also replace its postinc. We only
// do this if we also found a wide value for the head of the chain.
if (isa<PHINode>(Chain.back().UserInst)) {
if (isa<PHINode>(Chain.tailUserInst())) {
for (BasicBlock::iterator I = L->getHeader()->begin();
PHINode *Phi = dyn_cast<PHINode>(I); ++I) {
if (!isCompatibleIVType(Phi, IVSrc))
@ -4486,7 +4509,7 @@ LSRInstance::ImplementSolution(const SmallVectorImpl<const Formula *> &Solution,
// Mark phi nodes that terminate chains so the expander tries to reuse them.
for (SmallVectorImpl<IVChain>::const_iterator ChainI = IVChainVec.begin(),
ChainE = IVChainVec.end(); ChainI != ChainE; ++ChainI) {
if (PHINode *PN = dyn_cast<PHINode>(ChainI->back().UserInst))
if (PHINode *PN = dyn_cast<PHINode>(ChainI->tailUserInst()))
Rewriter.setChainedPhi(PN);
}