SILGenFunction::SILGenFunction(SILGenModule &SGM, SILFunction &F)
: SGM(SGM), F(F), silConv(SGM.M), StartOfPostmatter(F.end()),
B(*this, createBasicBlock()), OpenedArchetypesTracker(F),
CurrentSILLoc(F.getLocation()), Cleanups(*this) {
B.setCurrentDebugScope(F.getDebugScope());
B.setOpenedArchetypesTracker(&OpenedArchetypesTracker);
}
SILGenFunction::SILGenFunction(SILGenModule &SGM, SILFunction &F,
DeclContext *DC)
: SGM(SGM), F(F), silConv(SGM.M), FunctionDC(DC),
StartOfPostmatter(F.end()), B(*this), OpenedArchetypesTracker(&F),
CurrentSILLoc(F.getLocation()), Cleanups(*this),
StatsTracer(SGM.M.getASTContext().Stats, "SILGen-function", &F) {
assert(DC && "creating SGF without a DeclContext?");
B.setInsertionPoint(createBasicBlock());
B.setCurrentDebugScope(F.getDebugScope());
B.setOpenedArchetypesTracker(&OpenedArchetypesTracker);
}
static bool processFunction(SILFunction &Fn) {
bool Changed = false;
for (auto BI = Fn.begin(), BE = Fn.end(); BI != BE; ++BI) {
auto II = BI->begin(), IE = BI->end();
while (II != IE) {
SILInstruction *Inst = &*II;
DEBUG(llvm::dbgs() << "Visiting: " << *Inst);
if (auto *CA = dyn_cast<CopyAddrInst>(Inst))
if (expandCopyAddr(CA)) {
++II;
CA->eraseFromParent();
Changed = true;
continue;
}
if (auto *DA = dyn_cast<DestroyAddrInst>(Inst))
if (expandDestroyAddr(DA)) {
++II;
DA->eraseFromParent();
Changed = true;
continue;
}
if (auto *CV = dyn_cast<RetainValueInst>(Inst))
if (expandRetainValue(CV)) {
++II;
CV->eraseFromParent();
Changed = true;
continue;
}
if (auto *DV = dyn_cast<ReleaseValueInst>(Inst))
if (expandReleaseValue(DV)) {
++II;
DV->eraseFromParent();
Changed = true;
continue;
}
++II;
}
}
return Changed;
}
static bool removeUnreachableBlocks(SILFunction &F, SILModule &M,
UnreachableUserCodeReportingState *State) {
if (F.empty())
return false;
SILBasicBlockSet Reachable;
SmallVector<SILBasicBlock*, 128> Worklist;
Worklist.push_back(&F.front());
Reachable.insert(&F.front());
// Collect all reachable blocks by walking the successors.
do {
SILBasicBlock *BB = Worklist.pop_back_val();
for (auto SI = BB->succ_begin(), SE = BB->succ_end(); SI != SE; ++SI) {
if (Reachable.insert(*SI).second)
Worklist.push_back(*SI);
}
} while (!Worklist.empty());
assert(Reachable.size() <= F.size());
// If everything is reachable, we are done.
if (Reachable.size() == F.size())
return false;
// Diagnose user written unreachable code.
if (State) {
for (auto BI = State->PossiblyUnreachableBlocks.begin(),
BE = State->PossiblyUnreachableBlocks.end(); BI != BE; ++BI) {
const SILBasicBlock *BB = *BI;
if (!Reachable.count(BB)) {
llvm::SmallPtrSet<const SILBasicBlock *, 1> visited;
diagnoseUnreachableBlock(**BI, M, Reachable, State, BB, visited);
}
}
}
// Remove references from the dead blocks.
for (auto I = F.begin(), E = F.end(); I != E; ++I) {
SILBasicBlock *BB = &*I;
if (Reachable.count(BB))
continue;
// Drop references to other blocks.
recursivelyDeleteTriviallyDeadInstructions(BB->getTerminator(), true);
NumInstructionsRemoved++;
}
// Delete dead instructions and everything that could become dead after
// their deletion.
llvm::SmallVector<SILInstruction*, 32> ToBeDeleted;
for (auto BI = F.begin(), BE = F.end(); BI != BE; ++BI)
if (!Reachable.count(&*BI))
for (auto I = BI->begin(), E = BI->end(); I != E; ++I)
ToBeDeleted.push_back(&*I);
recursivelyDeleteTriviallyDeadInstructions(ToBeDeleted, true);
NumInstructionsRemoved += ToBeDeleted.size();
// Delete the dead blocks.
for (auto I = F.begin(), E = F.end(); I != E;)
if (!Reachable.count(&*I)) {
I = F.getBlocks().erase(I);
NumBlocksRemoved++;
} else
++I;
return true;
}