Turn invokes of nounwind functions into ordinary calls.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44280 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SimplifyCFG.cpp b/lib/Transforms/Scalar/SimplifyCFG.cpp
index 7400575..692a8af 100644
--- a/lib/Transforms/Scalar/SimplifyCFG.cpp
+++ b/lib/Transforms/Scalar/SimplifyCFG.cpp
@@ -71,6 +71,28 @@
}
}
+/// ChangeToCall - Convert the specified invoke into a normal call.
+static void ChangeToCall(InvokeInst *II) {
+ BasicBlock *BB = II->getParent();
+ SmallVector<Value*, 8> Args(II->op_begin()+3, II->op_end());
+ CallInst *NewCall = new CallInst(II->getCalledValue(), Args.begin(),
+ Args.end(), "", II);
+ NewCall->takeName(II);
+ NewCall->setCallingConv(II->getCallingConv());
+ NewCall->setParamAttrs(II->getParamAttrs());
+ II->replaceAllUsesWith(NewCall);
+
+ // Follow the call by a branch to the normal destination.
+ new BranchInst(II->getNormalDest(), II);
+
+ // Update PHI nodes in the unwind destination
+ II->getUnwindDest()->removePredecessor(BB);
+ BB->getInstList().erase(II);
+
+ if (NewCall->use_empty())
+ BB->getInstList().erase(NewCall);
+}
+
/// IsNoReturn - Return true if the specified call is to a no-return function.
static bool IsNoReturn(const CallInst *CI) {
if (const ParamAttrsList *Attrs = CI->getParamAttrs())
@@ -90,6 +112,25 @@
return false;
}
+/// IsNoUnwind - Return true if the specified invoke is to a no-unwind function.
+static bool IsNoUnwind(const InvokeInst *II) {
+ if (const ParamAttrsList *Attrs = II->getParamAttrs())
+ if (Attrs->paramHasAttr(0, ParamAttr::NoUnwind))
+ return true;
+
+ if (const Function *Callee = II->getCalledFunction()) {
+ if (const ParamAttrsList *Attrs = Callee->getParamAttrs())
+ if (Attrs->paramHasAttr(0, ParamAttr::NoUnwind))
+ return true;
+
+ const FunctionType *FT = Callee->getFunctionType();
+ if (const ParamAttrsList *Attrs = FT->getParamAttrs())
+ if (Attrs->paramHasAttr(0, ParamAttr::NoUnwind))
+ return true;
+ }
+ return false;
+}
+
static bool MarkAliveBlocks(BasicBlock *BB,
SmallPtrSet<BasicBlock*, 128> &Reachable) {
@@ -106,7 +147,7 @@
// Do a quick scan of the basic block, turning any obviously unreachable
// instructions into LLVM unreachable insts. The instruction combining pass
- // canonnicalizes unreachable insts into stores to null or undef.
+ // canonicalizes unreachable insts into stores to null or undef.
for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E;++BBI){
if (CallInst *CI = dyn_cast<CallInst>(BBI)) {
if (IsNoReturn(CI)) {
@@ -131,6 +172,13 @@
}
}
+ // Turn invokes that call 'nounwind' functions into ordinary calls.
+ if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator()))
+ if (IsNoUnwind(II)) {
+ ChangeToCall(II);
+ Changed = true;
+ }
+
Changed |= ConstantFoldTerminator(BB);
for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB); SI != SE; ++SI)
Worklist.push_back(*SI);