VM: More compact code for pushing constant arguments on ia32/x64.

runtime/vm/intermediate_language_x64.cc

 // Copyright (c) 2013, 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 "vm/dart_entry.h"
@@ skipping 220 matching lines @@
   ASSERT(result == value);  // Assert that register assignment is correct.
   __ movq(Address(RBP, local().index() * kWordSize), value);
 }
 
 
 LocationSummary* ConstantInstr::MakeLocationSummary(Zone* zone,
                                                     bool opt) const {
   const intptr_t kNumInputs = 0;
   return LocationSummary::Make(zone,
                                kNumInputs,
-                               Location::RequiresRegister(),
+                               Assembler::IsSafe(value())
+                                   ? Location::Constant(this)
+                                   : Location::RequiresRegister(),
                                LocationSummary::kNoCall);
 }
 
 
 void ConstantInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   // The register allocator drops constant definitions that have no uses.
-  if (!locs()->out(0).IsInvalid()) {
-    Register result = locs()->out(0).reg();
+  Location out = locs()->out(0);
+  ASSERT(out.IsRegister() || out.IsConstant() || out.IsInvalid());
+  if (out.IsRegister()) {
+    Register result = out.reg();
     __ LoadObject(result, value());
   }
 }
 
 
 LocationSummary* UnboxedConstantInstr::MakeLocationSummary(Zone* zone,
                                                            bool opt) const {
   const intptr_t kNumInputs = 0;
   const intptr_t kNumTemps = 0;
   LocationSummary* locs = new(zone) LocationSummary(
@@ skipping 6188 matching lines @@
   __ Drop(1);
   __ popq(result);
 }
 
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64