[CodeGen] skip lifetime end marker in isInTailCallPosition

A lifetime end intrinsic between a tail call and the return should not
prevent the call from being tail call optimized.

Differential Revision: https://reviews.llvm.org/D53519

llvm-svn: 345163

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/Analysis.cpp b/llvm/lib/CodeGen/Analysis.cpp
index aae04a573af..27dce7fd7b7 100644
--- a/llvm/lib/CodeGen/Analysis.cpp
+++ b/llvm/lib/CodeGen/Analysis.cpp
@@ -496,6 +496,10 @@ bool llvm::isInTailCallPosition(ImmutableCallSite CS, const TargetMachine &TM) {
       // Debug info intrinsics do not get in the way of tail call optimization.
       if (isa<DbgInfoIntrinsic>(BBI))
         continue;
+      // A lifetime end intrinsic should not stop tail call optimization.
+      if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(BBI))
+        if (II->getIntrinsicID() == Intrinsic::lifetime_end)
+          continue;
       if (BBI->mayHaveSideEffects() || BBI->mayReadFromMemory() ||
           !isSafeToSpeculativelyExecute(&*BBI))
         return false;