mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-17 21:29:20 +00:00
1. Correct some comments and clean up some dead code.
2. When calculating ANTIC_IN, only iterate the changed blocks. For most average inputs this is a small speedup, but for cases with unusual CFGs, this can be a significant win. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37742 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
parent
c33aa47130
commit
6032a5ba64
@ -377,7 +377,7 @@ namespace {
|
||||
SmallPtrSet<Value*, 32>& currExps,
|
||||
SmallPtrSet<Value*, 32>& currTemps,
|
||||
std::set<BasicBlock*>& visited);
|
||||
unsigned buildsets(Function& F);
|
||||
void buildsets(Function& F);
|
||||
|
||||
void insertion_pre(Value* e, BasicBlock* BB,
|
||||
std::map<BasicBlock*, Value*>& avail,
|
||||
@ -895,7 +895,7 @@ unsigned GVNPRE::buildsets_anticin(BasicBlock* BB,
|
||||
|
||||
/// buildsets - Phase 1 of the main algorithm. Construct the AVAIL_OUT
|
||||
/// and the ANTIC_IN sets.
|
||||
unsigned GVNPRE::buildsets(Function& F) {
|
||||
void GVNPRE::buildsets(Function& F) {
|
||||
std::map<BasicBlock*, SmallPtrSet<Value*, 32> > generatedExpressions;
|
||||
std::map<BasicBlock*, SmallPtrSet<PHINode*, 32> > generatedPhis;
|
||||
std::map<BasicBlock*, SmallPtrSet<Value*, 32> > generatedTemporaries;
|
||||
@ -937,32 +937,42 @@ unsigned GVNPRE::buildsets(Function& F) {
|
||||
// Phase 1, Part 2: calculate ANTIC_IN
|
||||
|
||||
std::set<BasicBlock*> visited;
|
||||
SmallPtrSet<BasicBlock*, 4> block_changed;
|
||||
for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI)
|
||||
block_changed.insert(FI);
|
||||
|
||||
bool changed = true;
|
||||
unsigned iterations = 0;
|
||||
|
||||
while (changed) {
|
||||
changed = false;
|
||||
SmallPtrSet<Value*, 32> anticOut;
|
||||
|
||||
// Top-down walk of the postdominator tree
|
||||
// Postorder walk of the CFG
|
||||
for (po_iterator<BasicBlock*> BBI = po_begin(&F.getEntryBlock()),
|
||||
BBE = po_end(&F.getEntryBlock()); BBI != BBE; ++BBI) {
|
||||
BasicBlock* BB = *BBI;
|
||||
if (BB == 0)
|
||||
continue;
|
||||
|
||||
unsigned ret = buildsets_anticin(BB, anticOut,generatedExpressions[BB],
|
||||
generatedTemporaries[BB], visited);
|
||||
if (block_changed.count(BB) != 0) {
|
||||
unsigned ret = buildsets_anticin(BB, anticOut,generatedExpressions[BB],
|
||||
generatedTemporaries[BB], visited);
|
||||
|
||||
if (ret == 0) {
|
||||
changed = true;
|
||||
continue;
|
||||
} else {
|
||||
visited.insert(BB);
|
||||
if (ret == 2) {
|
||||
DOUT << "CHANGED: " << BB->getName() << "\n";
|
||||
if (ret == 0) {
|
||||
changed = true;
|
||||
continue;
|
||||
} else {
|
||||
visited.insert(BB);
|
||||
|
||||
if (ret == 2)
|
||||
for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB);
|
||||
PI != PE; ++PI) {
|
||||
block_changed.insert(*PI);
|
||||
}
|
||||
else
|
||||
block_changed.erase(BB);
|
||||
|
||||
changed |= (ret == 2);
|
||||
}
|
||||
changed |= (ret == 2);
|
||||
}
|
||||
}
|
||||
|
||||
@ -970,8 +980,6 @@ unsigned GVNPRE::buildsets(Function& F) {
|
||||
}
|
||||
|
||||
DOUT << "ITERATIONS: " << iterations << "\n";
|
||||
|
||||
return 0; // No bail, no changes
|
||||
}
|
||||
|
||||
/// insertion_pre - When a partial redundancy has been identified, eliminate it
|
||||
@ -1173,10 +1181,7 @@ bool GVNPRE::runOnFunction(Function &F) {
|
||||
// This phase calculates the AVAIL_OUT and ANTIC_IN sets
|
||||
// NOTE: If full postdom information is no available, this will bail
|
||||
// early, performing GVN but not PRE
|
||||
unsigned bail = buildsets(F);
|
||||
//If a bail occurred, terminate early
|
||||
if (bail != 0)
|
||||
return (bail == 2);
|
||||
buildsets(F);
|
||||
|
||||
// Phase 2: Insert
|
||||
// This phase inserts values to make partially redundant values
|
||||
|
Loading…
Reference in New Issue
Block a user