Subzero: Implement "second-chance bin-packing" for register allocation.

src/IceClFlags.h

Index: src/IceClFlags.h
diff --git a/src/IceClFlags.h b/src/IceClFlags.h
index 0aba214c35e4d1f1a94dc1da1898e82310344d21..64fac195b13f40334247cc68daf5e6a788cbbbfc 100644
--- a/src/IceClFlags.h
+++ b/src/IceClFlags.h
@@ -106,6 +106,9 @@ public:
   bool shouldRandomizeRegAlloc() const { return RandomRegAlloc; }
   void setShouldRandomizeRegAlloc(bool NewValue) { RandomRegAlloc = NewValue; }
 
+  bool shouldRegAllocRepeat() const { return RegAllocRepeat; }

[John, 2015/10/09 20:13:04]

This reads a bit funny to me... maybe shouldRepeatRegAlloc?

[Jim Stichnoth, 2015/10/09 21:33:07]

Good point.  I changed all that to be RepeatRegAlloc.  Except for the
command-line argument string, I stuck with -regalloc-repeat for the hierarchical
aspect.

+  void setShouldRegAllocRepeat(bool NewValue) { RegAllocRepeat = NewValue; }
+
   bool getSkipUnimplemented() const { return SkipUnimplemented; }
   void setSkipUnimplemented(bool NewValue) { SkipUnimplemented = NewValue; }
 
@@ -262,6 +265,7 @@ private:
   bool PhiEdgeSplit;
   bool RandomNopInsertion;
   bool RandomRegAlloc;
+  bool RegAllocRepeat;
   bool ReorderBasicBlocks;
   bool ReorderFunctions;
   bool ReorderGlobalVariables;