Add simple full redundancy elimination.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37455 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2007-06-06 01:27:49 +00:00
parent b47f6124f4
commit 12112af5e8

View File

@ -77,7 +77,7 @@ namespace {
void dump_unique(ValueTable& VN, std::set<Value*, ExprLT>& s);
void clean(ValueTable VN, std::set<Value*, ExprLT>& set);
bool add(ValueTable& VN, std::set<Value*, ExprLT>& MS, Value* V);
Value* find_leader(ValueTable VN, std::set<Value*, ExprLT>& vals, Value* v);
Value* find_leader(std::set<Value*, ExprLT>& vals, Value* v);
Value* phi_translate(ValueTable& VN, std::set<Value*, ExprLT>& MS,
std::set<Value*, ExprLT>& set,
Value* V, BasicBlock* pred);
@ -120,8 +120,7 @@ bool GVNPRE::add(ValueTable& VN, std::set<Value*, ExprLT>& MS, Value* V) {
return ret.second;
}
Value* GVNPRE::find_leader(GVNPRE::ValueTable VN,
std::set<Value*, ExprLT>& vals,
Value* GVNPRE::find_leader(std::set<Value*, ExprLT>& vals,
Value* v) {
ExprLT cmp;
for (std::set<Value*, ExprLT>::iterator I = vals.begin(), E = vals.end();
@ -141,7 +140,7 @@ Value* GVNPRE::phi_translate(ValueTable& VN, std::set<Value*, ExprLT>& MS,
if (BinaryOperator* BO = dyn_cast<BinaryOperator>(V)) {
Value* newOp1 = isa<Instruction>(BO->getOperand(0))
? phi_translate(VN, MS, set,
find_leader(VN, set, BO->getOperand(0)),
find_leader(set, BO->getOperand(0)),
pred)
: BO->getOperand(0);
if (newOp1 == 0)
@ -149,7 +148,7 @@ Value* GVNPRE::phi_translate(ValueTable& VN, std::set<Value*, ExprLT>& MS,
Value* newOp2 = isa<Instruction>(BO->getOperand(1))
? phi_translate(VN, MS, set,
find_leader(VN, set, BO->getOperand(1)),
find_leader(set, BO->getOperand(1)),
pred)
: BO->getOperand(1);
if (newOp2 == 0)
@ -160,7 +159,7 @@ Value* GVNPRE::phi_translate(ValueTable& VN, std::set<Value*, ExprLT>& MS,
newOp1, newOp2,
BO->getName()+".gvnpre");
if (!find_leader(VN, set, newVal)) {
if (!find_leader(set, newVal)) {
add(VN, MS, newVal);
return newVal;
} else {
@ -241,8 +240,8 @@ void GVNPRE::topo_sort(GVNPRE::ValueTable& VN,
Value* e = Q.back();
if (BinaryOperator* BO = dyn_cast<BinaryOperator>(e)) {
Value* l = find_leader(VN, set, BO->getOperand(0));
Value* r = find_leader(VN, set, BO->getOperand(1));
Value* l = find_leader(set, BO->getOperand(0));
Value* r = find_leader(set, BO->getOperand(1));
if (l != 0 && isa<Instruction>(l) &&
visited.find(l) == visited.end())
@ -319,8 +318,6 @@ void GVNPRE::CalculateAvailOut(GVNPRE::ValueTable& VN, std::set<Value*, ExprLT>&
currExps.insert(rightValue);
currExps.insert(BO);
//currTemps.insert(BO);
// Handle unsupported ops
} else if (!BI->isTerminator()){
add(VN, MS, BI);
@ -344,7 +341,9 @@ bool GVNPRE::runOnFunction(Function &F) {
DominatorTree &DT = getAnalysis<DominatorTree>();
// First Phase of BuildSets - calculate AVAIL_OUT
// Phase 1: BuildSets
// Phase 1, Part 1: calculate AVAIL_OUT
// Top-down walk of the dominator tree
for (df_iterator<DomTreeNode*> DI = df_begin(DT.getRootNode()),
@ -366,7 +365,7 @@ bool GVNPRE::runOnFunction(Function &F) {
PostDominatorTree &PDT = getAnalysis<PostDominatorTree>();
// Second Phase of BuildSets - calculate ANTIC_IN
// Phase 1, Part 2: calculate ANTIC_IN
std::set<BasicBlock*> visited;
@ -476,5 +475,32 @@ bool GVNPRE::runOnFunction(Function &F) {
DOUT << "\n";
}
// Phase 2: Insert
// FIXME: Not implemented yet
// Phase 3: Eliminate
for (df_iterator<DomTreeNode*> DI = df_begin(DT.getRootNode()),
E = df_end(DT.getRootNode()); DI != E; ++DI) {
BasicBlock* BB = DI->getBlock();
std::vector<Instruction*> erase;
for (BasicBlock::iterator BI = BB->begin(), BE = BB->end();
BI != BE; ++BI) {
Value* leader = find_leader(availableOut[BB], BI);
if (leader != 0)
if (Instruction* Instr = dyn_cast<Instruction>(leader))
if (Instr->getParent() != 0 && Instr != BI) {
BI->replaceAllUsesWith(leader);
erase.push_back(BI);
}
}
for (std::vector<Instruction*>::iterator I = erase.begin(), E = erase.end();
I != E; ++I)
(*I)->eraseFromParent();
}
return false;
}