[llvm-commits] [llvm] r130596 - /llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp

[Jakob Stoklund Olesen]

Author: stoklund
Date: Sat Apr 30 00:07:46 2011
New Revision: 130596

URL: http://llvm.org/viewvc/llvm-project?rev=130596&view=rev
Log:
Use hysteresis for local live range splitting as well.

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

Modified: llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp?rev=130596&r1=130595&r2=130596&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp Sat Apr 30 00:07:46 2011
@@ -1225,13 +1225,13 @@
                               PrevSlot[SplitBefore].distance(Uses[SplitAfter]));
         // Would this split be possible to allocate?
         // Never allocate all gaps, we wouldn't be making progress.
-        float Diff = EstWeight - MaxGap;
-        DEBUG(dbgs() << " w=" << EstWeight << " d=" << Diff);
-        if (Diff > 0) {
+        DEBUG(dbgs() << " w=" << EstWeight);
+        if (EstWeight * Hysteresis >= MaxGap) {
           Shrink = false;
+          float Diff = EstWeight - MaxGap;
           if (Diff > BestDiff) {
             DEBUG(dbgs() << " (best)");
-            BestDiff = Diff;
+            BestDiff = Hysteresis * Diff;
             BestBefore = SplitBefore;
             BestAfter = SplitAfter;
           }