ARM: Reduce amount of code generated for LoadIC_Megamorphic....

src/ia32/stub-cache-ia32.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 146 matching lines @@
   return result;
 }
 
 
 void StubCache::GenerateProbe(MacroAssembler* masm,
                               Code::Flags flags,
                               Register receiver,
                               Register name,
                               Register scratch,
                               Register extra,
-                              Register extra2) {
+                              Register extra2,
+                              Register extra3) {
   Isolate* isolate = Isolate::Current();
   Label miss;
   USE(extra2);  // The register extra2 is not used on the ia32 platform.

[Søren Thygesen Gjesse, 2011/07/04 07:21:19]

Will a USE(extra3) be needed to compile in release mode?

[m.m.capewell, 2011/07/14 15:00:18]

Done.

 
   // Make sure that code is valid. The shifting code relies on the
   // entry size being 8.
   ASSERT(sizeof(Entry) == 8);
 
   // Make sure the flags does not name a specific type.
   ASSERT(Code::ExtractTypeFromFlags(flags) == 0);
 
   // Make sure that there are no register conflicts.
   ASSERT(!scratch.is(receiver));
   ASSERT(!scratch.is(name));
   ASSERT(!extra.is(receiver));
   ASSERT(!extra.is(name));
   ASSERT(!extra.is(scratch));
 
-  // Check scratch and extra registers are valid, and extra2 is unused.
+  // Check scratch is valid, extra2 and extra3 are unused.
   ASSERT(!scratch.is(no_reg));

[Søren Thygesen Gjesse, 2011/07/04 07:21:19]

Also assert that extra is not no_reg?

[m.m.capewell, 2011/07/14 15:00:18]

extra can be no_reg here, eg. ic-ia32.cc:877.

   ASSERT(extra2.is(no_reg));
+  ASSERT(extra3.is(no_reg));
 
   // Check that the receiver isn't a smi.
   __ JumpIfSmi(receiver, &miss);
 
   // Get the map of the receiver and compute the hash.
   __ mov(scratch, FieldOperand(name, String::kHashFieldOffset));
   __ add(scratch, FieldOperand(receiver, HeapObject::kMapOffset));
   __ xor_(scratch, flags);
   __ and_(scratch, (kPrimaryTableSize - 1) << kHeapObjectTagSize);
 
@@ skipping 3575 matching lines @@
       masm->isolate()->builtins()->KeyedStoreIC_MissForceGeneric();
   __ jmp(ic_force_generic, RelocInfo::CODE_TARGET);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32