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, 5 deletions

diff --git a/src/compiler/codegen/gen_common.cc b/src/compiler/codegen/gen_common.cc
index 0a46593159..2eaa6b0343 100644
--- a/src/compiler/codegen/gen_common.cc
+++ b/src/compiler/codegen/gen_common.cc
@@ -1419,13 +1419,14 @@ void Codegen::GenArithOpIntLit(CompilationUnit* cu, Instruction::Code opcode,
   switch (opcode) {
     case Instruction::RSUB_INT_LIT8:
     case Instruction::RSUB_INT: {
-      int t_reg;
-      //TUNING: add support for use of Arm rsub op
       rl_src = LoadValue(cu, rl_src, kCoreReg);
-      t_reg = AllocTemp(cu);
-      LoadConstant(cu, t_reg, lit);
       rl_result = EvalLoc(cu, rl_dest, kCoreReg, true);
-      OpRegRegReg(cu, kOpSub, rl_result.low_reg, t_reg, rl_src.low_reg);
+      if (cu->instruction_set == kThumb2) {
+        OpRegRegImm(cu, kOpRsub, rl_result.low_reg, rl_src.low_reg, lit);
+      } else {
+        OpRegReg(cu, kOpNeg, rl_result.low_reg, rl_src.low_reg);
+        OpRegImm(cu, kOpAdd, rl_result.low_reg, lit);
+      }
       StoreValue(cu, rl_dest, rl_result);
       return;
     }