[llvm] r258611 - [PruneEH] FuncletPads must not have undef operands

[David Majnemer via llvm-commits]

Author: majnemer
Date: Fri Jan 22 23:41:29 2016
New Revision: 258611

URL: http://llvm.org/viewvc/llvm-project?rev=258611&view=rev
Log:
[PruneEH] FuncletPads must not have undef operands

Instead of RAUW with undef, replace the first non-token instruction with
unreachable.

This fixes PR26263.

Added:
    llvm/trunk/test/Transforms/PruneEH/pr26263.ll
Modified:
    llvm/trunk/lib/Transforms/IPO/PruneEH.cpp

Modified: llvm/trunk/lib/Transforms/IPO/PruneEH.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/PruneEH.cpp?rev=258611&r1=258610&r2=258611&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/PruneEH.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/PruneEH.cpp Fri Jan 22 23:41:29 2016
@@ -228,10 +228,17 @@ void PruneEH::DeleteBasicBlock(BasicBloc
   assert(pred_empty(BB) && "BB is not dead!");
   CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
 
+  Instruction *TokenInst = nullptr;
+
   CallGraphNode *CGN = CG[BB->getParent()];
   for (BasicBlock::iterator I = BB->end(), E = BB->begin(); I != E; ) {
     --I;
 
+    if (I->getType()->isTokenTy()) {
+      TokenInst = &*I;
+      break;
+    }
+
     if (auto CS = CallSite (&*I)) {
       const Function *Callee = CS.getCalledFunction();
       if (!Callee || !Intrinsic::isLeaf(Callee->getIntrinsicID()))
@@ -244,11 +251,15 @@ void PruneEH::DeleteBasicBlock(BasicBloc
       I->replaceAllUsesWith(UndefValue::get(I->getType()));
   }
 
-  // Get the list of successors of this block.
-  std::vector<BasicBlock*> Succs(succ_begin(BB), succ_end(BB));
+  if (TokenInst) {
+    changeToUnreachable(TokenInst->getNextNode(), /*UseLLVMTrap=*/false);
+  } else {
+    // Get the list of successors of this block.
+    std::vector<BasicBlock *> Succs(succ_begin(BB), succ_end(BB));
 
-  for (unsigned i = 0, e = Succs.size(); i != e; ++i)
-    Succs[i]->removePredecessor(BB);
+    for (unsigned i = 0, e = Succs.size(); i != e; ++i)
+      Succs[i]->removePredecessor(BB);
 
-  BB->eraseFromParent();
+    BB->eraseFromParent();
+  }
 }

Added: llvm/trunk/test/Transforms/PruneEH/pr26263.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/PruneEH/pr26263.ll?rev=258611&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/PruneEH/pr26263.ll (added)
+++ llvm/trunk/test/Transforms/PruneEH/pr26263.ll Fri Jan 22 23:41:29 2016
@@ -0,0 +1,30 @@
+; RUN: opt -prune-eh -S < %s | FileCheck %s
+target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
+target triple = "i386-pc-windows-msvc"
+
+declare void @neverthrows() nounwind
+
+define void @test1() personality i32 (...)* @__CxxFrameHandler3 {
+  invoke void @neverthrows()
+          to label %try.cont unwind label %cleanuppad
+
+try.cont:
+  ret void
+
+cleanuppad:
+  %cp = cleanuppad within none []
+  br label %cleanupret
+
+cleanupret:
+  cleanupret from %cp unwind to caller
+}
+
+; CHECK-LABEL: define void @test1(
+; CHECK: call void @neverthrows()
+
+; CHECK: %[[cp:.*]] = cleanuppad within none []
+; CHECK-NEXT: unreachable
+
+; CHECK: cleanupret from %[[cp]] unwind to caller
+
+declare i32 @__CxxFrameHandler3(...)