The IC exposes a register definition.

src/ia32/stub-cache-ia32.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_IA32
 
 #include "src/codegen.h"
 #include "src/ic-inl.h"
@@ skipping 1265 matching lines @@
   __ mov(eax, isolate()->factory()->undefined_value());
   __ ret(0);
 
   // Return the generated code.
   return GetCode(kind(), Code::FAST, name);
 }
 
 
 Register* LoadStubCompiler::registers() {
   // receiver, name, scratch1, scratch2, scratch3, scratch4.
-  static Register registers[] = { edx, ecx, ebx, eax, edi, no_reg };
+  Register receiver = LoadIC::ReceiverRegister();
+  Register name = LoadIC::NameRegister();
+  static Register registers[] = { receiver, name, ebx, eax, edi, no_reg };
   return registers;
 }
 
 
 Register* KeyedLoadStubCompiler::registers() {
   // receiver, name, scratch1, scratch2, scratch3, scratch4.
-  static Register registers[] = { edx, ecx, ebx, eax, edi, no_reg };
+  Register receiver = KeyedLoadIC::ReceiverRegister();
+  Register name = KeyedLoadIC::NameRegister();
+  static Register registers[] = { receiver, name, ebx, eax, edi, no_reg };
   return registers;
 }
 
 
 Register StoreStubCompiler::value() {
   return eax;
 }
 
 
 Register* StoreStubCompiler::registers() {
@@ skipping 181 matching lines @@
   // -----------------------------------
   TailCallBuiltin(masm, Builtins::kKeyedLoadIC_Miss);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32