Clean up EmitSmiBinaryOp template to remove redundant moves.

runtime/vm/intermediate_language_x64.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intermediate_language.h"
 
 #include "lib/error.h"
@@ skipping 1497 matching lines @@
       break;
     default:
       can_deopt = true;
   }
   Label* deopt = NULL;
   if (can_deopt) {
     deopt = compiler->AddDeoptStub(comp->instance_call()->deopt_id(),
                                    comp->instance_call()->try_index(),
                                    kDeoptSmiBinaryOp);
   }
-  if (left_is_smi && right_is_smi) {
-    if (can_deopt) {
-      // Preserve left for deopt.
-      __ movq(temp, left);
-    }
-  } else {
-    // TODO(vegorov): for many binary operations this pattern can be rearranged
-    // to save one move.
+  if (!left_is_smi || !right_is_smi) {
     __ movq(temp, left);
-    __ orq(left, right);
-    __ testq(left, Immediate(kSmiTagMask));
+    __ orq(temp, right);
+    __ testq(temp, Immediate(kSmiTagMask));
     __ j(NOT_ZERO, deopt);
-    __ movq(left, temp);
   }
   switch (comp->op_kind()) {
     case Token::kADD: {
       __ addq(left, right);
       __ j(OVERFLOW, deopt);
       break;
     }
     case Token::kSUB: {
       __ subq(left, right);
       __ j(OVERFLOW, deopt);
@@ skipping 56 matching lines @@
       __ Bind(&count_ok);
       ASSERT(right == RCX);  // Count must be in RCX
       __ SmiUntag(left);
       __ sarq(left, right);
       __ SmiTag(left);
       break;
     }
     case Token::kSHL: {
       Label call_method, done;
       // Check if count too large for handling it inlined.
+      __ movq(temp, left);
       __ cmpq(right,
           Immediate(reinterpret_cast<int64_t>(Smi::New(Smi::kBits))));
       __ j(ABOVE_EQUAL, &call_method, Assembler::kNearJump);
       Register right_temp = comp->locs()->temp(1).reg();
       ASSERT(right_temp == RCX);  // Count must be in RCX
       __ movq(right_temp, right);
       __ SmiUntag(right_temp);
       // Overflow test (preserve temp and right);
       __ shlq(left, right_temp);
       __ sarq(left, right_temp);
@@ skipping 606 matching lines @@
     }
   }
   __ Bind(&is_ok);
 }
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64