Don't walk into predecessors in which the vreg is not live when doing shrinkwrapping.

This lets several failing tests get farther along, but doesn't completely fix any of them.

llvm-svn: 59086

1 files changed, 2 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/PreAllocSplitting.cpp b/llvm/lib/CodeGen/PreAllocSplitting.cpp
index 09f002aa265..f7d8ab01026 100644
--- a/llvm/lib/CodeGen/PreAllocSplitting.cpp
+++ b/llvm/lib/CodeGen/PreAllocSplitting.cpp
@@ -618,6 +618,8 @@ PreAllocSplitting::ShrinkWrapLiveInterval(VNInfo *ValNo, MachineBasicBlock *MBB,
       // Pred is the def bb and the def reaches other val#s, we must
       // allow the value to be live out of the bb.
       continue;
+    if (!CurrLI->liveAt(LIs->getMBBEndIdx(Pred)-1))
+      return;
     ShrinkWrapLiveInterval(ValNo, Pred, MBB, DefMBB, Visited,
                            Uses, UseMIs, UseMBBs);
   }