Exemple #1
0
// FIXME: This code is stolen from CallGraph::addToCallGraph(Function *F), which
// happens to be private. It is better for this functionality exposed by the
// CallGraph.
static void buildCGN(CallGraph &CG, CallGraphNode *Node) {
  Function *F = Node->getFunction();

  // Look for calls by this function.
  for (Instruction &I : instructions(F))
    if (CallSite CS = CallSite(cast<Value>(&I))) {
      const Function *Callee = CS.getCalledFunction();
      if (!Callee || !Intrinsic::isLeaf(Callee->getIntrinsicID()))
        // Indirect calls of intrinsics are not allowed so no need to check.
        // We can be more precise here by using TargetArg returned by
        // Intrinsic::isLeaf.
        Node->addCalledFunction(CS, CG.getCallsExternalNode());
      else if (!Callee->isIntrinsic())
        Node->addCalledFunction(CS, CG.getOrInsertFunction(Callee));
    }
}
Exemple #2
0
// When we see the coroutine the first time, we insert an indirect call to a
// devirt trigger function and mark the coroutine that it is now ready for
// split.
static void prepareForSplit(Function &F, CallGraph &CG) {
  Module &M = *F.getParent();
#ifndef NDEBUG
  Function *DevirtFn = M.getFunction(CORO_DEVIRT_TRIGGER_FN);
  assert(DevirtFn && "coro.devirt.trigger function not found");
#endif

  F.addFnAttr(CORO_PRESPLIT_ATTR, PREPARED_FOR_SPLIT);

  // Insert an indirect call sequence that will be devirtualized by CoroElide
  // pass:
  //    %0 = call i8* @llvm.coro.subfn.addr(i8* null, i8 -1)
  //    %1 = bitcast i8* %0 to void(i8*)*
  //    call void %1(i8* null)
  coro::LowererBase Lowerer(M);
  Instruction *InsertPt = F.getEntryBlock().getTerminator();
  auto *Null = ConstantPointerNull::get(Type::getInt8PtrTy(F.getContext()));
  auto *DevirtFnAddr =
      Lowerer.makeSubFnCall(Null, CoroSubFnInst::RestartTrigger, InsertPt);
  auto *IndirectCall = CallInst::Create(DevirtFnAddr, Null, "", InsertPt);

  // Update CG graph with an indirect call we just added.
  CG[&F]->addCalledFunction(IndirectCall, CG.getCallsExternalNode());
}