[llvm-commits] [llvm] r149910 - /llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp

[Jakob Stoklund Olesen]

Author: stoklund
Date: Mon Feb  6 15:52:18 2012
New Revision: 149910

URL: http://llvm.org/viewvc/llvm-project?rev=149910&view=rev
Log:
Make sure a reserved register has a live interval before merging.

Modified:
    llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp

Modified: llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp?rev=149910&r1=149909&r2=149910&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp Mon Feb  6 15:52:18 2012
@@ -1414,8 +1414,12 @@
       // Deny any overlapping intervals.  This depends on all the reserved
       // register live ranges to look like dead defs.
       for (const unsigned *AS = TRI->getOverlaps(CP.getDstReg()); *AS; ++AS) {
-        if (!LIS->hasInterval(*AS))
+        if (!LIS->hasInterval(*AS)) {
+          // Make sure at least DstReg itself exists before attempting a join.
+          if (*AS == CP.getDstReg())
+            LIS->getOrCreateInterval(CP.getDstReg());
           continue;
+        }
         if (RHS.overlaps(LIS->getInterval(*AS))) {
           DEBUG(dbgs() << "\t\tInterference: " << PrintReg(*AS, TRI) << '\n');
           return false;