6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-13 04:30:23 +00:00
Code Issues Projects Releases Wiki Activity

Real fix for PR3549, by using caching for predecessor counts in addition to the predecessors themselves. This halves the time

Browse Source 
to optimize the testcase, beyond what my previous patch did.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69792 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2009-04-22 08:50:12 +00:00
parent ddcb3415cb
commit 7db2789251
1 changed files with 13 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
lib/Transforms/Utils/LCSSA.cpp
View File

@ -86,7 +86,8 @@ namespace {
}
private:
void getLoopValuesUsedOutsideLoop(Loop *L,
SetVector<Instruction*> &AffectedValues);
SetVector<Instruction*> &AffectedValues,
const SmallVector<BasicBlock*, 8>& exitBlocks);
Value *GetValueForBlock(DomTreeNode *BB, Instruction *OrigInst,
DenseMap<DomTreeNode*, Value*> &Phis);
@ -116,17 +117,17 @@ bool LCSSA::runOnLoop(Loop *L, LPPassManager &LPM) {
LoopBlocks.insert(LoopBlocks.end(), L->block_begin(), L->block_end());
std::sort(LoopBlocks.begin(), LoopBlocks.end());
SmallVector<BasicBlock*, 8> exitBlocks;
L->getExitBlocks(exitBlocks);
SetVector<Instruction*> AffectedValues;
getLoopValuesUsedOutsideLoop(L, AffectedValues);
getLoopValuesUsedOutsideLoop(L, AffectedValues, exitBlocks);
// If no values are affected, we can save a lot of work, since we know that
// nothing will be changed.
if (AffectedValues.empty())
return false;
SmallVector<BasicBlock*, 8> exitBlocks;
L->getExitBlocks(exitBlocks);
// Iterate over all affected values for this loop and insert Phi nodes
// for them in the appropriate exit blocks
@ -160,7 +161,7 @@ void LCSSA::ProcessInstruction(Instruction *Instr,
if (!Phi && DT->dominates(InstrNode, ExitBBNode)) {
PHINode *PN = PHINode::Create(Instr->getType(), Instr->getName()+".lcssa",
BB->begin());
PN->reserveOperandSpace(std::distance(pred_begin(BB), pred_end(BB)));
PN->reserveOperandSpace(PredCache.GetNumPreds(BB));
// Remember that this phi makes the value alive in this block.
Phi = PN;
@ -202,15 +203,16 @@ void LCSSA::ProcessInstruction(Instruction *Instr,
/// getLoopValuesUsedOutsideLoop - Return any values defined in the loop that
/// are used by instructions outside of it.
void LCSSA::getLoopValuesUsedOutsideLoop(Loop *L,
SetVector<Instruction*> &AffectedValues) {
SetVector<Instruction*> &AffectedValues,
const SmallVector<BasicBlock*, 8>& exitBlocks) {
// FIXME: For large loops, we may be able to avoid a lot of use-scanning
// by using dominance information. In particular, if a block does not
// dominate any of the loop exits, then none of the values defined in the
// block could be used outside the loop.
for (Loop::block_iterator BB = L->block_begin(), E = L->block_end();
BB != E; ++BB) {
for (Loop::block_iterator BB = L->block_begin(), BE = L->block_end();
BB != BE; ++BB) {
for (BasicBlock::iterator I = (*BB)->begin(), E = (*BB)->end(); I != E; ++I)
for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E;
for (Value::use_iterator UI = I->use_begin(), UE = I->use_end(); UI != UE;
++UI) {
BasicBlock *UserBB = cast<Instruction>(*UI)->getParent();
if (PHINode* p = dyn_cast<PHINode>(*UI)) {
@ -263,7 +265,7 @@ Value *LCSSA::GetValueForBlock(DomTreeNode *BB, Instruction *OrigInst,
// now, then get values to fill in the incoming values for the PHI.
PHINode *PN = PHINode::Create(OrigInst->getType(),
OrigInst->getName() + ".lcssa", BBN->begin());
PN->reserveOperandSpace(std::distance(pred_begin(BBN), pred_end(BBN)));
PN->reserveOperandSpace(PredCache.GetNumPreds(BBN));
Phis.insert(std::make_pair(BB, PN));
// Fill in the incoming values for the block.