C++ Exp::isRegOf方法代码示例

// Substitute s into all members of the set
void LocationSet::substitute(Assign& a)
{
    Exp* lhs = a.getLeft();
    if (lhs == NULL) return;
    Exp* rhs = a.getRight();
    if (rhs == NULL) return;		// ? Will this ever happen?
    std::set<Exp*, lessExpStar>::iterator it;
    // Note: it's important not to change the pointer in the set of pointers to expressions, without removing and
    // inserting again. Otherwise, the set becomes out of order, and operations such as set comparison fail!
    // To avoid any funny behaviour when iterating the loop, we use the following two sets
    LocationSet removeSet;			// These will be removed after the loop
    LocationSet removeAndDelete;	// These will be removed then deleted
    LocationSet insertSet;			// These will be inserted after the loop
    bool change;
    for (it = lset.begin(); it != lset.end(); it++)
        {
            Exp* loc = *it;
            Exp* replace;
            if (loc->search(lhs, replace))
                {
                    if (rhs->isTerminal())
                        {
                            // This is no longer a location of interest (e.g. %pc)
                            removeSet.insert(loc);
                            continue;
                        }
                    loc = loc->clone()->searchReplaceAll(lhs, rhs, change);
                    if (change)
                        {
                            loc = loc->simplifyArith();
                            loc = loc->simplify();
                            // If the result is no longer a register or memory (e.g.
                            // r[28]-4), then delete this expression and insert any
                            // components it uses (in the example, just r[28])
                            if (!loc->isRegOf() && !loc->isMemOf())
                                {
                                    // Note: can't delete the expression yet, because the
                                    // act of insertion into the remove set requires silent
                                    // calls to the compare function
                                    removeAndDelete.insert(*it);
                                    loc->addUsedLocs(insertSet);
                                    continue;
                                }
                            // Else we just want to replace it
                            // Regardless of whether the top level expression pointer has
                            // changed, remove and insert it from the set of pointers
                            removeSet.insert(*it);		// Note: remove the unmodified ptr
                            insertSet.insert(loc);
                        }
                }
        }
    makeDiff(removeSet);	   // Remove the items to be removed
    makeDiff(removeAndDelete); // These are to be removed as well
    makeUnion(insertSet);	   // Insert the items to be added
    // Now delete the expressions that are no longer needed
    std::set<Exp*, lessExpStar>::iterator dd;
    for (dd = removeAndDelete.lset.begin(); dd != removeAndDelete.lset.end();
            dd++)
        delete *dd;				// Plug that memory leak
}

bool DataFlow::renameBlockVars(UserProc* proc, int n, bool clearStacks /* = false */ ) {
	if (++progress > 200) {
		std::cerr << 'r' << std::flush;
		progress = 0;
	}
	bool changed = false;

	// Need to clear the Stacks of old, renamed locations like m[esp-4] (these will be deleted, and will cause compare
	// failures in the Stacks, so it can't be correctly ordered and hence balanced etc, and will lead to segfaults)
	if (clearStacks) Stacks.clear();

	// For each statement S in block n
	BasicBlock::rtlit rit; StatementList::iterator sit;
	PBB bb = BBs[n];
	Statement* S;
	for (S = bb->getFirstStmt(rit, sit); S; S = bb->getNextStmt(rit, sit)) {
		// if S is not a phi function (per Appel)
		/* if (!S->isPhi()) */ {
			// For each use of some variable x in S (not just assignments)
			LocationSet locs;
			if (S->isPhi()) {
				PhiAssign* pa = (PhiAssign*)S;
				Exp* phiLeft = pa->getLeft();
				if (phiLeft->isMemOf() || phiLeft->isRegOf())
					phiLeft->getSubExp1()->addUsedLocs(locs);
				// A phi statement may use a location defined in a childless call, in which case its use collector
				// needs updating
				PhiAssign::iterator pp;
				for (pp = pa->begin(); pp != pa->end(); ++pp) {
					Statement* def = pp->def;
					if (def && def->isCall())
						((CallStatement*)def)->useBeforeDefine(phiLeft->clone());
				}
			}
			else {				// Not a phi assignment
				S->addUsedLocs(locs);
			}
			LocationSet::iterator xx;
			for (xx = locs.begin(); xx != locs.end(); xx++) {
				Exp* x = *xx;
				// Don't rename memOfs that are not renamable according to the current policy
				if (!canRename(x, proc)) continue;
				Statement* def = NULL;
				if (x->isSubscript()) {					// Already subscripted?
					// No renaming required, but redo the usage analysis, in case this is a new return, and also because
					// we may have just removed all call livenesses
					// Update use information in calls, and in the proc (for parameters)
					Exp* base = ((RefExp*)x)->getSubExp1();
					def = ((RefExp*)x)->getDef();
					if (def && def->isCall()) {
						// Calls have UseCollectors for locations that are used before definition at the call
						((CallStatement*)def)->useBeforeDefine(base->clone());
						continue;
					}
					// Update use collector in the proc (for parameters)
					if (def == NULL)
						proc->useBeforeDefine(base->clone());
					continue;							// Don't re-rename the renamed variable
				}
				// Else x is not subscripted yet
				if (STACKS_EMPTY(x)) {
					if (!Stacks[defineAll].empty())
						def = Stacks[defineAll].top();
					else {
						// If the both stacks are empty, use a NULL definition. This will be changed into a pointer
						// to an implicit definition at the start of type analysis, but not until all the m[...]
						// have stopped changing their expressions (complicates implicit assignments considerably).
						def = NULL;
						// Update the collector at the start of the UserProc
						proc->useBeforeDefine(x->clone());
					}
				}
				else
					def = Stacks[x].top();
				if (def && def->isCall())
					// Calls have UseCollectors for locations that are used before definition at the call
					((CallStatement*)def)->useBeforeDefine(x->clone());
				// Replace the use of x with x{def} in S
				changed = true;
				if (S->isPhi()) {
					Exp* phiLeft = ((PhiAssign*)S)->getLeft();
					phiLeft->setSubExp1(phiLeft->getSubExp1()->expSubscriptVar(x, def /*, this*/));
				} else {
					S->subscriptVar(x, def /*, this */);
				}
			}
		}

		// MVE: Check for Call and Return Statements; these have DefCollector objects that need to be updated
		// Do before the below, so CallStatements have not yet processed their defines
		if (S->isCall() || S->isReturn()) {
			DefCollector* col;
			if (S->isCall())
				col = ((CallStatement*)S)->getDefCollector();
			else
				col = ((ReturnStatement*)S)->getCollector();
			col->updateDefs(Stacks, proc);
		}

		// For each definition of some variable a in S
//.........这里部分代码省略.........