The IC exposes a register definition.

src/ia32/stub-cache-ia32.cc

Index: src/ia32/stub-cache-ia32.cc
diff --git a/src/ia32/stub-cache-ia32.cc b/src/ia32/stub-cache-ia32.cc
index e70e5a24b97ef654af830078224aa2841884b68c..a69619495b54c0b556f9a8fcc7459ae833deac7f 100644
--- a/src/ia32/stub-cache-ia32.cc
+++ b/src/ia32/stub-cache-ia32.cc
@@ -1283,14 +1283,18 @@ Handle<Code> LoadStubCompiler::CompileLoadNonexistent(Handle<HeapType> type,
 
 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;
 }