Codegen tweaks

Minor codegen cleanup.  Most significant part of change is
fixing dalvik register use counting to correctly record
cost of high word of register pair.  Significant boost to
Reversi benchmark; modest gain for Caffeinemark.

Change-Id: I41819e6d7be93e62d259240269339a94a934f312

1 files changed, 6 insertions, 11 deletions

diff --git a/src/compiler/codegen/ralloc_util.cc b/src/compiler/codegen/ralloc_util.cc
index 1d5f3aca86..3a3aeba332 100644
--- a/src/compiler/codegen/ralloc_util.cc
+++ b/src/compiler/codegen/ralloc_util.cc
@@ -1082,27 +1082,22 @@ RegLocation GetSrcWide(CompilationUnit* cu, MIR* mir,
 static void CountRefs(CompilationUnit *cu, BasicBlock* bb, RefCounts* core_counts,
                       RefCounts* fp_counts)
 {
+  // TUNING: this routine could use some tweaking.
   if ((cu->disable_opt & (1 << kPromoteRegs)) ||
     !((bb->block_type == kEntryBlock) || (bb->block_type == kExitBlock) ||
       (bb->block_type == kDalvikByteCode))) {
     return;
   }
-  for (int i = 0; i < cu->num_ssa_regs;) {
+  for (int i = 0; i < cu->num_ssa_regs; i++) {
     RegLocation loc = cu->reg_location[i];
     RefCounts* counts = loc.fp ? fp_counts : core_counts;
     int p_map_idx = SRegToPMap(cu, loc.s_reg_low);
     //Don't count easily regenerated immediates
-    if (loc.fp || loc.wide || !IsInexpensiveConstant(cu, loc)) {
-      counts[p_map_idx].count += cu->use_counts.elem_list[i];
+    if (loc.fp || !IsInexpensiveConstant(cu, loc)) {
+      counts[p_map_idx].count += cu->raw_use_counts.elem_list[i];
     }
-    if (loc.wide) {
-      if (loc.fp) {
-        counts[p_map_idx].double_start = true;
-        counts[p_map_idx+1].count += cu->use_counts.elem_list[i+1];
-      }
-      i += 2;
-    } else {
-      i++;
+    if (loc.wide && loc.fp && !loc.high_word) {
+      counts[p_map_idx].double_start = true;
     }
   }
 }