The IC exposes a register definition.

src/arm/ic-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_ARM
 
 #include "src/arm/assembler-arm.h"
 #include "src/code-stubs.h"
@@ skipping 527 matching lines @@
   __ Push(r1, r0);
 
   // Perform tail call to the entry.
   ExternalReference ref =
       ExternalReference(IC_Utility(kKeyedLoadIC_Miss), isolate);
 
   __ TailCallExternalReference(ref, 2, 1);
 }
 
 
+// IC register specifications
+const Register LoadIC::ReceiverRegister() { return r0; }
+const Register LoadIC::NameRegister() { return r2; }
+const Register KeyedLoadIC::ReceiverRegister() { return r1; }
+const Register KeyedLoadIC::NameRegister() { return r0; }
+
+
 void KeyedLoadIC::GenerateRuntimeGetProperty(MacroAssembler* masm) {
   // ---------- S t a t e --------------
   //  -- lr     : return address
   //  -- r0     : key
   //  -- r1     : receiver
   // -----------------------------------
 
   __ Push(r1, r0);
 
   __ TailCallRuntime(Runtime::kKeyedGetProperty, 2, 1);
@@ skipping 754 matching lines @@
   } else {
     ASSERT(Assembler::GetCondition(branch_instr) == ne);
     patcher.EmitCondition(eq);
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM