bool mssa::runOnFunction(Function &F) {
MemorySSA *MSSA = &getAnalysis<MemorySSAWrapperPass>().getMSSA();
//MemorySSAWalker MAW = new MemorySSAWalker(MSSA);
errs()<<"\n";
for (Function::iterator BB = F.begin(); BB != F.end(); BB++){
errs() << "Basic block (name=" << BB->getName() << ")\n";
//Get MemoryPhi and print it out
MemoryPhi* MP = MSSA->getMemoryAccess(dyn_cast<BasicBlock>(BB));
if (MP != NULL)
MP->dump();
for (BasicBlock::iterator itrIns = (*BB).begin(); itrIns != (*BB).end(); itrIns++) {
//MemoryAccess* MA = MAW.getClobberingMemoryAccess(itrIns);
//MemoryLocation Location;
//MemoryAccess* MAR = MAW.getClobberingMemoryAccess(MA,&Location);
//MAR->dump();
errs()<<"Instruction: "<< *itrIns <<"\n";
//Get MemoryDef or MemoryUse and print it out
MemoryAccess *MA = MSSA->getMemoryAccess(dyn_cast<Value>(itrIns));
if (MA != NULL) {
MA->dump();
//if(MSSA->isLiveOnEntryDef(MA))
//Get immediate MemoryDef of the instruction annotated MemoryDef/MemoryUse
for (memoryaccess_def_iterator MAitr = MA->defs_begin();
MAitr != MA->defs_end();
MAitr++)
{
errs()<<"Def: "<<**MAitr<<"\n";
//Get the instruction the immediate Memory Def annotation represent
Instruction* u = cast<MemoryUseOrDef>(*MAitr)->getMemoryInst();
if (u != NULL)
errs()<<" Def Inst: "<<*u<<"\n";
}
}
}
}
return 0;
}
static bool simplifyLoopInst(Loop &L, DominatorTree &DT, LoopInfo &LI,
AssumptionCache &AC, const TargetLibraryInfo &TLI,
MemorySSAUpdater *MSSAU) {
const DataLayout &DL = L.getHeader()->getModule()->getDataLayout();
SimplifyQuery SQ(DL, &TLI, &DT, &AC);
// On the first pass over the loop body we try to simplify every instruction.
// On subsequent passes, we can restrict this to only simplifying instructions
// where the inputs have been updated. We end up needing two sets: one
// containing the instructions we are simplifying in *this* pass, and one for
// the instructions we will want to simplify in the *next* pass. We use
// pointers so we can swap between two stably allocated sets.
SmallPtrSet<const Instruction *, 8> S1, S2, *ToSimplify = &S1, *Next = &S2;
// Track the PHI nodes that have already been visited during each iteration so
// that we can identify when it is necessary to iterate.
SmallPtrSet<PHINode *, 4> VisitedPHIs;
// While simplifying we may discover dead code or cause code to become dead.
// Keep track of all such instructions and we will delete them at the end.
SmallVector<Instruction *, 8> DeadInsts;
// First we want to create an RPO traversal of the loop body. By processing in
// RPO we can ensure that definitions are processed prior to uses (for non PHI
// uses) in all cases. This ensures we maximize the simplifications in each
// iteration over the loop and minimizes the possible causes for continuing to
// iterate.
LoopBlocksRPO RPOT(&L);
RPOT.perform(&LI);
MemorySSA *MSSA = MSSAU ? MSSAU->getMemorySSA() : nullptr;
bool Changed = false;
for (;;) {
if (MSSAU && VerifyMemorySSA)
MSSA->verifyMemorySSA();
for (BasicBlock *BB : RPOT) {
for (Instruction &I : *BB) {
if (auto *PI = dyn_cast<PHINode>(&I))
VisitedPHIs.insert(PI);
if (I.use_empty()) {
if (isInstructionTriviallyDead(&I, &TLI))
DeadInsts.push_back(&I);
continue;
}
// We special case the first iteration which we can detect due to the
// empty `ToSimplify` set.
bool IsFirstIteration = ToSimplify->empty();
if (!IsFirstIteration && !ToSimplify->count(&I))
continue;
Value *V = SimplifyInstruction(&I, SQ.getWithInstruction(&I));
if (!V || !LI.replacementPreservesLCSSAForm(&I, V))
continue;
for (Value::use_iterator UI = I.use_begin(), UE = I.use_end();
UI != UE;) {
Use &U = *UI++;
auto *UserI = cast<Instruction>(U.getUser());
U.set(V);
// If the instruction is used by a PHI node we have already processed
// we'll need to iterate on the loop body to converge, so add it to
// the next set.
if (auto *UserPI = dyn_cast<PHINode>(UserI))
if (VisitedPHIs.count(UserPI)) {
Next->insert(UserPI);
continue;
}
// If we are only simplifying targeted instructions and the user is an
// instruction in the loop body, add it to our set of targeted
// instructions. Because we process defs before uses (outside of PHIs)
// we won't have visited it yet.
//
// We also skip any uses outside of the loop being simplified. Those
// should always be PHI nodes due to LCSSA form, and we don't want to
// try to simplify those away.
assert((L.contains(UserI) || isa<PHINode>(UserI)) &&
"Uses outside the loop should be PHI nodes due to LCSSA!");
if (!IsFirstIteration && L.contains(UserI))
ToSimplify->insert(UserI);
}
if (MSSAU)
if (Instruction *SimpleI = dyn_cast_or_null<Instruction>(V))
if (MemoryAccess *MA = MSSA->getMemoryAccess(&I))
if (MemoryAccess *ReplacementMA = MSSA->getMemoryAccess(SimpleI))
MA->replaceAllUsesWith(ReplacementMA);
assert(I.use_empty() && "Should always have replaced all uses!");
if (isInstructionTriviallyDead(&I, &TLI))
DeadInsts.push_back(&I);
++NumSimplified;
Changed = true;
}
}
// Delete any dead instructions found thus far now that we've finished an
// iteration over all instructions in all the loop blocks.
if (!DeadInsts.empty()) {
Changed = true;
RecursivelyDeleteTriviallyDeadInstructions(DeadInsts, &TLI, MSSAU);
}
if (MSSAU && VerifyMemorySSA)
MSSA->verifyMemorySSA();
// If we never found a PHI that needs to be simplified in the next
// iteration, we're done.
if (Next->empty())
break;
// Otherwise, put the next set in place for the next iteration and reset it
// and the visited PHIs for that iteration.
std::swap(Next, ToSimplify);
Next->clear();
VisitedPHIs.clear();
DeadInsts.clear();
}
return Changed;
}
TestAnalyses(MemorySSATest &Test)
: DT(*Test.F), AC(*Test.F), AA(Test.TLI),
BAA(Test.DL, Test.TLI, AC, &DT), MSSA(*Test.F) {
AA.addAAResult(BAA);
Walker.reset(MSSA.buildMemorySSA(&AA, &DT));
}
