[DebugInfo] Remove call sites when eliminating unreachable blocks

Summary:
When eliminating an unreachable block we must remove any call site
information for calls residing in the block.

This was originally found on a downstream target, and the attached x86
test case was produced by hand-modifying some MIR.

Reviewers: aprantl, asowda, NikolaPrica, djtodoro, ivanbaev, vsk

Reviewed By: NikolaPrica, vsk

Subscribers: vsk, hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D64500

llvm-svn: 368566

1 files changed, 7 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/UnreachableBlockElim.cpp b/llvm/lib/CodeGen/UnreachableBlockElim.cpp
index 177bab32bcc..c5343690329 100644
--- a/llvm/lib/CodeGen/UnreachableBlockElim.cpp
+++ b/llvm/lib/CodeGen/UnreachableBlockElim.cpp
@@ -146,8 +146,14 @@ bool UnreachableMachineBlockElim::runOnMachineFunction(MachineFunction &F) {
   }
 
   // Actually remove the blocks now.
-  for (unsigned i = 0, e = DeadBlocks.size(); i != e; ++i)
+  for (unsigned i = 0, e = DeadBlocks.size(); i != e; ++i) {
+    // Remove any call site information for calls in the block.
+    for (auto &I : DeadBlocks[i]->instrs())
+      if (I.isCall(MachineInstr::IgnoreBundle))
+        DeadBlocks[i]->getParent()->updateCallSiteInfo(&I);
+
     DeadBlocks[i]->eraseFromParent();
+  }
 
   // Cleanup PHI nodes.
   for (MachineFunction::iterator I = F.begin(), E = F.end(); I != E; ++I) {