Add support for non-local CSE of read-only calls.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51024 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2008-05-13 08:17:22 +00:00
parent d6a2218586
commit 3b3f58cb77

View File

@ -56,8 +56,8 @@ namespace {
FCMPULT, FCMPULE, FCMPUNE, EXTRACT, INSERT,
SHUFFLE, SELECT, TRUNC, ZEXT, SEXT, FPTOUI,
FPTOSI, UITOFP, SITOFP, FPTRUNC, FPEXT,
PTRTOINT, INTTOPTR, BITCAST, GEP, CALL, EMPTY,
TOMBSTONE };
PTRTOINT, INTTOPTR, BITCAST, GEP, CALL, CONSTANT,
EMPTY, TOMBSTONE };
ExpressionOpcode opcode;
const Type* type;
@ -147,6 +147,7 @@ namespace {
Expression create_expression(CastInst* C);
Expression create_expression(GetElementPtrInst* G);
Expression create_expression(CallInst* C);
Expression create_expression(Constant* C);
public:
ValueTable() : nextValueNumber(1) { }
uint32_t lookup_or_add(Value* V);
@ -391,7 +392,7 @@ Expression ValueTable::create_expression(SelectInst* I) {
Expression ValueTable::create_expression(GetElementPtrInst* G) {
Expression e;
e.firstVN = lookup_or_add(G->getPointerOperand());
e.secondVN = 0;
e.thirdVN = 0;
@ -434,26 +435,58 @@ uint32_t ValueTable::lookup_or_add(Value* V) {
} else if (AA->onlyReadsMemory(C)) {
Expression e = create_expression(C);
Instruction* dep = MD->getDependency(C);
if (dep == MemoryDependenceAnalysis::NonLocal ||
!isa<CallInst>(dep)) {
if (expressionNumbering.find(e) == expressionNumbering.end()) {
expressionNumbering.insert(std::make_pair(e, nextValueNumber));
valueNumbering.insert(std::make_pair(V, nextValueNumber));
return nextValueNumber++;
}
DenseMap<BasicBlock*, Value*> deps;
MD->getNonLocalDependency(C, deps);
Value* dep = 0;
for (DenseMap<BasicBlock*, Value*>::iterator I = deps.begin(),
E = deps.end(); I != E; ++I) {
if (I->second == MemoryDependenceAnalysis::None) {
valueNumbering.insert(std::make_pair(V, nextValueNumber));
return nextValueNumber++;
} else if (I->second != MemoryDependenceAnalysis::NonLocal) {
if (DT->dominates(I->first, C->getParent())) {
dep = I->second;
} else {
valueNumbering.insert(std::make_pair(V, nextValueNumber));
return nextValueNumber++;
}
}
}
if (!dep || !isa<CallInst>(dep)) {
valueNumbering.insert(std::make_pair(V, nextValueNumber));
return nextValueNumber++;
}
CallInst* cdep = cast<CallInst>(dep);
Expression d_exp = create_expression(cdep);
if (e != d_exp) {
expressionNumbering.insert(std::make_pair(e, nextValueNumber));
if (cdep->getCalledFunction() != C->getCalledFunction() ||
cdep->getNumOperands() != C->getNumOperands()) {
valueNumbering.insert(std::make_pair(V, nextValueNumber));
return nextValueNumber++;
} else if (!C->getCalledFunction()) {
valueNumbering.insert(std::make_pair(V, nextValueNumber));
return nextValueNumber++;
} else {
uint32_t v = expressionNumbering[d_exp];
for (unsigned i = 1; i < C->getNumOperands(); ++i) {
uint32_t c_vn = lookup_or_add(C->getOperand(i));
uint32_t cd_vn = lookup_or_add(cdep->getOperand(i));
if (c_vn != cd_vn) {
valueNumbering.insert(std::make_pair(V, nextValueNumber));
return nextValueNumber++;
}
}
uint32_t v = valueNumbering[cdep];
valueNumbering.insert(std::make_pair(V, v));
return v;
}