Allows unboxed doubles to be disabled.

runtime/vm/flow_graph_compiler_arm.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_ARM.
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
 #include "vm/compiler.h"
 #include "vm/cpu.h"
 #include "vm/dart_entry.h"
 #include "vm/deopt_instructions.h"
 #include "vm/il_printer.h"
 #include "vm/locations.h"
 #include "vm/object_store.h"
 #include "vm/parser.h"
 #include "vm/stack_frame.h"
 #include "vm/stub_code.h"
 #include "vm/symbols.h"
 
 namespace dart {
 
 DEFINE_FLAG(bool, trap_on_deoptimization, false, "Trap on deoptimization.");
 DEFINE_FLAG(bool, unbox_mints, true, "Optimize 64-bit integer arithmetic.");
+DEFINE_FLAG(bool, unbox_doubles, true, "Optimize double arithmetic.");
 DECLARE_FLAG(int, optimization_counter_threshold);
 DECLARE_FLAG(int, reoptimization_counter_threshold);
 DECLARE_FLAG(bool, enable_type_checks);
 DECLARE_FLAG(bool, eliminate_type_checks);
 DECLARE_FLAG(bool, enable_simd_inline);
 
 
 FlowGraphCompiler::~FlowGraphCompiler() {
   // BlockInfos are zone-allocated, so their destructors are not called.
   // Verify the labels explicitly here.
   for (int i = 0; i < block_info_.length(); ++i) {
     ASSERT(!block_info_[i]->jump_label()->IsLinked());
   }
 }
 
 
+bool FlowGraphCompiler::SupportsUnboxedDoubles() {
+  return TargetCPUFeatures::vfp_supported() && FLAG_unbox_doubles;
+}
+
+
 bool FlowGraphCompiler::SupportsUnboxedMints() {
   return TargetCPUFeatures::neon_supported() && FLAG_unbox_mints;
 }
 
 
 bool FlowGraphCompiler::SupportsUnboxedSimd128() {
   return TargetCPUFeatures::neon_supported() && FLAG_enable_simd_inline;
 }
 
 
@@ skipping 1536 matching lines @@
       __ LoadFromOffset(kWord, destination.reg(), FP, source_offset);
     } else {
       ASSERT(destination.IsStackSlot());
       const intptr_t source_offset = source.ToStackSlotOffset();
       const intptr_t dest_offset = destination.ToStackSlotOffset();
       __ LoadFromOffset(kWord, TMP, FP, source_offset);
       __ StoreToOffset(kWord, TMP, FP, dest_offset);
     }
   } else if (source.IsFpuRegister()) {
     if (destination.IsFpuRegister()) {
-      __ vmovq(destination.fpu_reg(), source.fpu_reg());
+      if (TargetCPUFeatures::neon_supported()) {
+        __ vmovq(destination.fpu_reg(), source.fpu_reg());
+      } else {
+        // If we're not inlining simd values, then only the even numbered D
+        // register will have anything in them.
+        __ vmovd(EvenDRegisterOf(destination.fpu_reg()),
+                 EvenDRegisterOf(source.fpu_reg()));
+      }
     } else {
       if (destination.IsDoubleStackSlot()) {
         const intptr_t dest_offset = destination.ToStackSlotOffset();
         DRegister src = EvenDRegisterOf(source.fpu_reg());
         __ StoreDToOffset(src, FP, dest_offset);
       } else {
         ASSERT(destination.IsQuadStackSlot());
         const intptr_t dest_offset = destination.ToStackSlotOffset();
         const DRegister dsrc0 = EvenDRegisterOf(source.fpu_reg());
         __ StoreMultipleDToOffset(dsrc0, 2, FP, dest_offset);
@@ skipping 194 matching lines @@
   DRegister dreg = EvenDRegisterOf(reg);
   __ vldrd(dreg, Address(SP, kDoubleSize, Address::PostIndex));
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM