void deadVariableElimination(FnSymbol* fn) {
Vec<Symbol*> symSet;
collectSymbolSet(fn, symSet);
Map<Symbol*,Vec<SymExpr*>*> defMap;
Map<Symbol*,Vec<SymExpr*>*> useMap;
buildDefUseMaps(symSet, defMap, useMap);
forv_Vec(Symbol, sym, symSet)
{
// We're interested only in VarSymbols.
if (!isVarSymbol(sym))
continue;
// A method must have a _this symbol, even if it is not used.
if (sym == fn->_this)
continue;
if (isDeadVariable(sym, defMap, useMap)) {
for_defs(se, defMap, sym) {
CallExpr* call = toCallExpr(se->parentExpr);
INT_ASSERT(call &&
(call->isPrimitive(PRIM_MOVE) ||
call->isPrimitive(PRIM_ASSIGN)));
Expr* rhs = call->get(2)->remove();
if (!isSymExpr(rhs))
call->replace(rhs);
else
call->remove();
}
sym->defPoint->remove();
}
}
void deadVariableElimination(FnSymbol* fn) {
std::set<Symbol*> symSet;
collectSymbolSet(fn, symSet);
// Use 'symSet' and 'todo' together for a unique queue of symbols to process
std::queue<Symbol*> todo;
for_set(Symbol, sym, symSet) {
todo.push(sym);
}