From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Sat, 12 May 2012 00:33:28 +0000 (+0000)
Subject: Don't look for empty live ranges in the unions.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=2b3fa322b8788e62e28bc6989a53737bf9483437;p=oota-llvm.git

Don't look for empty live ranges in the unions.

Empty live ranges represent undef and still get allocated, but they
won't appear in LiveIntervalUnions.

Patch by Patrik Hägglund!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156685 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/RegAllocBase.cpp b/lib/CodeGen/RegAllocBase.cpp
index b00eceb17f1..b8d1d185e9f 100644
--- a/lib/CodeGen/RegAllocBase.cpp
+++ b/lib/CodeGen/RegAllocBase.cpp
@@ -69,11 +69,14 @@ void RegAllocBase::verify() {
   for (LiveIntervals::iterator liItr = LIS->begin(), liEnd = LIS->end();
        liItr != liEnd; ++liItr) {
     unsigned reg = liItr->first;
+    LiveInterval* li = liItr->second;
     if (TargetRegisterInfo::isPhysicalRegister(reg)) continue;
     if (!VRM->hasPhys(reg)) continue; // spilled?
+    if (li->empty()) continue; // unionVRegs will only be filled if li is
+                               // non-empty
     unsigned PhysReg = VRM->getPhys(reg);
     if (!unionVRegs[PhysReg].test(reg)) {
-      dbgs() << "LiveVirtReg " << reg << " not in union " <<
+      dbgs() << "LiveVirtReg " << PrintReg(reg, TRI) << " not in union " <<
         TRI->getName(PhysReg) << "\n";
       llvm_unreachable("unallocated live vreg");
     }