MIPS: Optimize AccessArgumentsAt.

src/mips/lithium-mips.cc

Index: src/mips/lithium-mips.cc
diff --git a/src/mips/lithium-mips.cc b/src/mips/lithium-mips.cc
index fa653c6436e8bb0a426fac3d073eb30df25246e4..34e5838557a0ee528fad7b574c42be8aad570f08 100644
--- a/src/mips/lithium-mips.cc
+++ b/src/mips/lithium-mips.cc
@@ -2459,15 +2459,8 @@ LInstruction* LChunkBuilder::DoCapturedObject(HCapturedObject* instr) {
 LInstruction* LChunkBuilder::DoAccessArgumentsAt(HAccessArgumentsAt* instr) {
   info()->MarkAsRequiresFrame();
   LOperand* args = UseRegister(instr->arguments());
-  LOperand* length;
-  LOperand* index;
-  if (instr->length()->IsConstant() && instr->index()->IsConstant()) {
-    length = UseRegisterOrConstant(instr->length());
-    index = UseOrConstant(instr->index());
-  } else {
-    length = UseTempRegister(instr->length());
-    index = UseRegisterAtStart(instr->index());
-  }
+  LOperand* length = UseRegisterOrConstantAtStart(instr->length());
+  LOperand* index = UseRegisterOrConstantAtStart(instr->index());
   return DefineAsRegister(new(zone()) LAccessArgumentsAt(args, length, index));
 }