[llvm] r187438 - Down-scale slot index distance to save bits.

[Andrew Trick]

Author: atrick
Date: Tue Jul 30 14:59:19 2013
New Revision: 187438

URL: http://llvm.org/viewvc/llvm-project?rev=187438&view=rev
Log:
Down-scale slot index distance to save bits.

Modified:
    llvm/trunk/include/llvm/CodeGen/SlotIndexes.h
    llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp

Modified: llvm/trunk/include/llvm/CodeGen/SlotIndexes.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/SlotIndexes.h?rev=187438&r1=187437&r2=187438&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/SlotIndexes.h (original)
+++ llvm/trunk/include/llvm/CodeGen/SlotIndexes.h Tue Jul 30 14:59:19 2013
@@ -218,6 +218,13 @@ namespace llvm {
       return other.getIndex() - getIndex();
     }
 
+    /// Return the scaled distance from this index to the given one, where all
+    /// slots on the same instruction have zero distance.
+    int getInstrDistance(SlotIndex other) const {
+      return (other.listEntry()->getIndex() - listEntry()->getIndex())
+        / Slot_Count;
+    }
+
     /// isBlock - Returns true if this is a block boundary slot.
     bool isBlock() const { return getSlot() == Slot_Block; }
 

Modified: llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp?rev=187438&r1=187437&r2=187438&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp Tue Jul 30 14:59:19 2013
@@ -419,7 +419,7 @@ void RAGreedy::enqueue(LiveInterval *LI)
       // Allocate original local ranges in linear instruction order. Since they
       // are singly defined, this produces optimal coloring in the absence of
       // global interference and other constraints.
-      Prio = LI->beginIndex().distance(Indexes->getLastIndex());
+      Prio = LI->beginIndex().getInstrDistance(Indexes->getLastIndex());
     }
     else {
       // Allocate global and split ranges in long->short order. Long ranges that