Add test case for r311511

This also changes the TailDuplicator to be configured explicitely
pre/post regalloc rather than relying on the isSSA() flag. This was
necessary to have `llc -run-pass` work reliably.

llvm-svn: 311520

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/MachineBlockPlacement.cpp b/llvm/lib/CodeGen/MachineBlockPlacement.cpp
index 65330308dad..c30f306a169 100644
--- a/llvm/lib/CodeGen/MachineBlockPlacement.cpp
+++ b/llvm/lib/CodeGen/MachineBlockPlacement.cpp
@@ -2729,7 +2729,8 @@ bool MachineBlockPlacement::runOnMachineFunction(MachineFunction &MF) {
     MPDT = &getAnalysis<MachinePostDominatorTree>();
     if (MF.getFunction()->optForSize())
       TailDupSize = 1;
-    TailDup.initMF(MF, MBPI, /* LayoutMode */ true, TailDupSize);
+    bool PreRegAlloc = false;
+    TailDup.initMF(MF, PreRegAlloc, MBPI, /* LayoutMode */ true, TailDupSize);
     precomputeTriangleChains();
   }