[llvm] r196536 - Check hint registers for interference only once before evictions

[Aditya Nandakumar]

Author: aditya_nandakumar
Date: Thu Dec  5 15:18:40 2013
New Revision: 196536

URL: http://llvm.org/viewvc/llvm-project?rev=196536&view=rev
Log:
Check hint registers for interference only once before evictions

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

Modified: llvm/trunk/lib/CodeGen/AllocationOrder.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AllocationOrder.h?rev=196536&r1=196535&r2=196536&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AllocationOrder.h (original)
+++ llvm/trunk/lib/CodeGen/AllocationOrder.h Thu Dec  5 15:18:40 2013
@@ -45,10 +45,12 @@ public:
   /// Return the next physical register in the allocation order, or 0.
   /// It is safe to call next() again after it returned 0, it will keep
   /// returning 0 until rewind() is called.
-  unsigned next() {
+  unsigned next(unsigned Limit = 0) {
     if (Pos < 0)
       return Hints.end()[Pos++];
-    while (Pos < int(Order.size())) {
+    if (!Limit)
+      Limit = Order.size();
+    while (Pos < int(Limit)) {
       unsigned Reg = Order[Pos++];
       if (!isHint(Reg))
         return Reg;

Modified: llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp?rev=196536&r1=196535&r2=196536&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp Thu Dec  5 15:18:40 2013
@@ -723,7 +723,7 @@ unsigned RAGreedy::tryEvict(LiveInterval
   }
 
   Order.rewind();
-  while (unsigned PhysReg = Order.nextWithDups(OrderLimit)) {
+  while (unsigned PhysReg = Order.next(OrderLimit)) {
     if (TRI->getCostPerUse(PhysReg) >= CostPerUseLimit)
       continue;
     // The first use of a callee-saved register in a function has cost 1.