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Add support for performing GVNPRE on GEP instructions. 

llvm-svn: 37862
This commit is contained in:
Owen Anderson 2007-07-03 23:51:19 +00:00
parent 9d1ff65719
commit 2e4b6feac2
2 changed files with 179 additions and 5 deletions
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167
llvm/lib/Transforms/Scalar/GVNPRE.cpp
View File

@ -477,6 +477,19 @@ uint32_t ValueTable::lookup_or_add(Value* V) {
} else if (CastInst* U = dyn_cast<CastInst>(V)) {
Expression e = create_expression(U);
std::map<Expression, uint32_t>::iterator EI = expressionNumbering.find(e);
if (EI != expressionNumbering.end()) {
valueNumbering.insert(std::make_pair(V, EI->second));
return EI->second;
} else {
expressionNumbering.insert(std::make_pair(e, nextValueNumber));
valueNumbering.insert(std::make_pair(V, nextValueNumber));
return nextValueNumber++;
}
} else if (GetElementPtrInst* U = dyn_cast<GetElementPtrInst>(V)) {
Expression e = create_expression(U);
std::map<Expression, uint32_t>::iterator EI = expressionNumbering.find(e);
if (EI != expressionNumbering.end()) {
valueNumbering.insert(std::make_pair(V, EI->second));
@ -798,6 +811,48 @@ Value* GVNPRE::phi_translate(Value* V, BasicBlock* pred, BasicBlock* succ) {
}
}
// Varargs operators
} else if (GetElementPtrInst* U = dyn_cast<GetElementPtrInst>(V)) {
Value* newOp1 = 0;
if (isa<Instruction>(U->getPointerOperand()))
newOp1 = phi_translate(U->getPointerOperand(), pred, succ);
else
newOp1 = U->getPointerOperand();
if (newOp1 == 0)
return 0;
bool changed_idx = false;
std::vector<Value*> newIdx;
for (GetElementPtrInst::op_iterator I = U->idx_begin(), E = U->idx_end();
I != E; ++I)
if (isa<Instruction>(*I)) {
Value* newVal = phi_translate(*I, pred, succ);
newIdx.push_back(newVal);
if (newVal != *I)
changed_idx = true;
} else {
newIdx.push_back(*I);
}
if (newOp1 != U->getPointerOperand() || changed_idx) {
Instruction* newVal = new GetElementPtrInst(U->getPointerOperand(),
&newIdx[0], newIdx.size(),
U->getName()+".expr");
uint32_t v = VN.lookup_or_add(newVal);
Value* leader = find_leader(availableOut[pred], v);
if (leader == 0) {
createdExpressions.push_back(newVal);
return newVal;
} else {
VN.erase(newVal);
delete newVal;
return leader;
}
}
// PHI Nodes
} else if (PHINode* P = dyn_cast<PHINode>(V)) {
if (P->getParent() == succ)
@ -900,6 +955,26 @@ void GVNPRE::clean(SmallPtrSet<Value*, 16>& set, BitVector& presentInSet) {
set.erase(U);
presentInSet.flip(VN.lookup(U));
}
// Handle varargs ops
} else if (GetElementPtrInst* U = dyn_cast<GetElementPtrInst>(v)) {
bool ptrValid = !isa<Instruction>(U->getPointerOperand());
ptrValid |= presentInSet.test(VN.lookup(U->getPointerOperand()));
if (ptrValid)
ptrValid = !dependsOnInvoke(U->getPointerOperand());
bool varValid = true;
for (GetElementPtrInst::op_iterator I = U->idx_begin(), E = U->idx_end();
I != E; ++I)
if (varValid) {
varValid &= !isa<Instruction>(*I) || presentInSet.test(VN.lookup(*I));
varValid &= !dependsOnInvoke(*I);
}
if (!ptrValid || !varValid) {
set.erase(U);
presentInSet.flip(VN.lookup(U));
}
}
}
}
@ -972,6 +1047,31 @@ void GVNPRE::topo_sort(SmallPtrSet<Value*, 16>& set, std::vector<Value*>& vec) {
stack.pop_back();
}
// Handle vararg ops
} else if (GetElementPtrInst* U = dyn_cast<GetElementPtrInst>(e)) {
Value* p = find_leader(set, VN.lookup(U->getPointerOperand()));
if (p != 0 && isa<Instruction>(p) &&
visited.count(p) == 0)
stack.push_back(p);
else {
bool push_va = false;
for (GetElementPtrInst::op_iterator I = U->idx_begin(),
E = U->idx_end(); I != E; ++I) {
Value * v = find_leader(set, VN.lookup(*I));
if (v != 0 && isa<Instruction>(v) && visited.count(v) == 0) {
stack.push_back(v);
push_va = true;
}
}
if (!push_va) {
vec.push_back(e);
visited.insert(e);
stack.pop_back();
}
}
// Handle opaque ops
} else {
visited.insert(e);
@ -1022,7 +1122,7 @@ bool GVNPRE::elimination() {
if (isa<BinaryOperator>(BI) || isa<CmpInst>(BI) ||
isa<ShuffleVectorInst>(BI) || isa<InsertElementInst>(BI) ||
isa<ExtractElementInst>(BI) || isa<SelectInst>(BI) ||
isa<CastInst>(BI)) {
isa<CastInst>(BI) || isa<GetElementPtrInst>(BI)) {
Value *leader = find_leader(availableOut[BB], VN.lookup(BI));
if (leader != 0)
@ -1160,6 +1260,34 @@ void GVNPRE::buildsets_availout(BasicBlock::iterator I,
expNumbers.set(num);
}
// Handle vararg ops
} else if (GetElementPtrInst* U = dyn_cast<GetElementPtrInst>(I)) {
Value* ptrValue = U->getPointerOperand();
VN.lookup_or_add(U);
unsigned num = VN.lookup_or_add(U);
expNumbers.resize(VN.size());
availNumbers.resize(VN.size());
if (isa<Instruction>(ptrValue))
if (!expNumbers.test(VN.lookup(ptrValue))) {
currExps.insert(ptrValue);
expNumbers.set(VN.lookup(ptrValue));
}
for (GetElementPtrInst::op_iterator OI = U->idx_begin(), OE = U->idx_end();
OI != OE; ++OI)
if (isa<Instruction>(*OI) && !expNumbers.test(VN.lookup(*OI))) {
currExps.insert(*OI);
expNumbers.set(VN.lookup(*OI));
}
if (!expNumbers.test(VN.lookup(U))) {
currExps.insert(U);
expNumbers.set(num);
}
// Handle opaque ops
} else if (!I->isTerminator()){
VN.lookup_or_add(I);
@ -1373,7 +1501,8 @@ void GVNPRE::insertion_pre(Value* e, BasicBlock* BB,
isa<ExtractElementInst>(U->getOperand(0)) ||
isa<InsertElementInst>(U->getOperand(0)) ||
isa<SelectInst>(U->getOperand(0)) ||
isa<CastInst>(U->getOperand(0)))
isa<CastInst>(U->getOperand(0)) ||
isa<GetElementPtrInst>(U->getOperand(0)))
s1 = find_leader(availableOut[*PI], VN.lookup(U->getOperand(0)));
else
s1 = U->getOperand(0);
@ -1392,7 +1521,8 @@ void GVNPRE::insertion_pre(Value* e, BasicBlock* BB,
isa<ExtractElementInst>(U->getOperand(1)) ||
isa<InsertElementInst>(U->getOperand(1)) ||
isa<SelectInst>(U->getOperand(1)) ||
isa<CastInst>(U->getOperand(1))) {
isa<CastInst>(U->getOperand(1)) ||
isa<GetElementPtrInst>(U->getOperand(1))) {
s2 = find_leader(availableOut[*PI], VN.lookup(U->getOperand(1)));
} else {
s2 = U->getOperand(1);
@ -1409,12 +1539,34 @@ void GVNPRE::insertion_pre(Value* e, BasicBlock* BB,
isa<ExtractElementInst>(U->getOperand(2)) ||
isa<InsertElementInst>(U->getOperand(2)) ||
isa<SelectInst>(U->getOperand(2)) ||
isa<CastInst>(U->getOperand(2))) {
isa<CastInst>(U->getOperand(2)) ||
isa<GetElementPtrInst>(U->getOperand(2))) {
s3 = find_leader(availableOut[*PI], VN.lookup(U->getOperand(2)));
} else {
s3 = U->getOperand(2);
}
// Vararg operators
std::vector<Value*> sVarargs;
if (GetElementPtrInst* G = dyn_cast<GetElementPtrInst>(U)) {
for (GetElementPtrInst::op_iterator OI = G->idx_begin(),
OE = G->idx_end(); OI != OE; ++OI) {
if (isa<BinaryOperator>(*OI) ||
isa<CmpInst>(*OI) ||
isa<ShuffleVectorInst>(*OI) ||
isa<ExtractElementInst>(*OI) ||
isa<InsertElementInst>(*OI) ||
isa<SelectInst>(*OI) ||
isa<CastInst>(*OI) ||
isa<GetElementPtrInst>(*OI)) {
sVarargs.push_back(find_leader(availableOut[*PI],
VN.lookup(*OI)));
} else {
sVarargs.push_back(*OI);
}
}
}
Value* newVal = 0;
if (BinaryOperator* BO = dyn_cast<BinaryOperator>(U))
newVal = BinaryOperator::create(BO->getOpcode(), s1, s2,
@ -1441,6 +1593,10 @@ void GVNPRE::insertion_pre(Value* e, BasicBlock* BB,
newVal = CastInst::create(C->getOpcode(), s1, C->getType(),
C->getName()+".gvnpre",
(*PI)->getTerminator());
else if (GetElementPtrInst* G = dyn_cast<GetElementPtrInst>(U))
newVal = new GetElementPtrInst(s1, &sVarargs[0], sVarargs.size(),
G->getName()+".gvnpre",
(*PI)->getTerminator());
VN.add(newVal, VN.lookup(U));
@ -1487,7 +1643,8 @@ unsigned GVNPRE::insertion_mergepoint(std::vector<Value*>& workList,
if (isa<BinaryOperator>(e) || isa<CmpInst>(e) ||
isa<ExtractElementInst>(e) || isa<InsertElementInst>(e) ||
isa<ShuffleVectorInst>(e) || isa<SelectInst>(e) || isa<CastInst>(e)) {
isa<ShuffleVectorInst>(e) || isa<SelectInst>(e) || isa<CastInst>(e) ||
isa<GetElementPtrInst>(e)) {
if (find_leader(availableOut[D->getIDom()->getBlock()],
VN.lookup(e)) != 0)
continue;

17
llvm/test/Transforms/GVNPRE/gep.ll Normal file
View File

@ -0,0 +1,17 @@
; RUN: llvm-as < %s | opt -gvnpre | llvm-dis | grep b.gvnpre
define i32 @extract({ i32 }* %P) {
entry: ; preds = %cond_false, %entry
br i1 true, label %cond_true, label %cond_false
cond_true:
br label %end
cond_false:
%a = getelementptr { i32 }* %P, i32 0, i32 0
br label %end
end:
%b = getelementptr { i32 }* %P, i32 0, i32 0
ret i32 0
}