From: Andrew Trick <atrick@apple.com>
Date: Tue, 7 Jun 2011 00:38:12 +0000 (+0000)
Subject: Fix a merge bug in preRAsched for handling physreg aliases.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=9d507aec07c7e22c6ba83dfd75e23c8630cd25cd;p=oota-llvm.git

Fix a merge bug in preRAsched for handling physreg aliases.

I've been sitting on this long enough trying to find a test case. I
think the fix should go in now, but I'll keep working on the test case.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132701 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
index 88bd4509b46..14717e6406f 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
@@ -1008,14 +1008,16 @@ static void CheckForLiveRegDef(SUnit *SU, unsigned Reg,
   for (const unsigned *AliasI = TRI->getOverlaps(Reg); *AliasI; ++AliasI) {
 
     // Check if Ref is live.
-    if (!LiveRegDefs[Reg]) continue;
+    if (!LiveRegDefs[*AliasI]) continue;
 
     // Allow multiple uses of the same def.
-    if (LiveRegDefs[Reg] == SU) continue;
+    if (LiveRegDefs[*AliasI] == SU) continue;
 
     // Add Reg to the set of interfering live regs.
-    if (RegAdded.insert(Reg))
-      LRegs.push_back(Reg);
+    if (RegAdded.insert(*AliasI)) {
+      assert(*AliasI == Reg && "alias clobber"); //!!!
+      LRegs.push_back(*AliasI);
+    }
   }
 }