Merge ConstantInstr -> UnboxDouble to UnboxedConstant. Reduces register usage and allows for variou…

runtime/vm/flow_graph_compiler_ia32.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_IA32.
 #if defined(TARGET_ARCH_IA32)
 
 #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/flow_graph_builder.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 {
 
@@ skipping 1617 matching lines @@
     }
   } else {
     ASSERT(source.IsConstant());
     if (destination.IsRegister()) {
       const Object& constant = source.constant();
       if (constant.IsSmi() && (Smi::Cast(constant).Value() == 0)) {
         __ xorl(destination.reg(), destination.reg());
       } else {
         __ LoadObjectSafely(destination.reg(), constant);
       }
+    } else if (destination.IsFpuRegister()) {
+      const Double& constant = Double::Cast(source.constant());
+      uword addr = FlowGraphBuilder::FindDoubleConstant(constant.value());
+      if (addr == 0) {
+        __ pushl(EAX);
+        __ LoadObject(EAX, constant);
+        __ movsd(destination.fpu_reg(),
+            FieldAddress(EAX, Double::value_offset()));
+        __ popl(EAX);
+      } else {
+        __ movsd(destination.fpu_reg(), Address::Absolute(addr));
+      }
     } else {
       ASSERT(destination.IsStackSlot());
       StoreObject(destination.ToStackSlotAddress(), source.constant());
     }
   }
 
   move->Eliminate();
 }
 
 
@@ skipping 143 matching lines @@
   __ movups(reg, Address(ESP, 0));
   __ addl(ESP, Immediate(kFpuRegisterSize));
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32