The IC exposes a register definition.

src/ia32/ic-ia32.cc

Index: src/ia32/ic-ia32.cc
diff --git a/src/ia32/ic-ia32.cc b/src/ia32/ic-ia32.cc
index b0e4ca0c60c2675899383b5a0fd95fe16546115d..0b3d110d1148948a7c5a4f0cc8234d2cfd4a3c5d 100644
--- a/src/ia32/ic-ia32.cc
+++ b/src/ia32/ic-ia32.cc
@@ -1025,6 +1025,19 @@ void KeyedLoadIC::GenerateMiss(MacroAssembler* masm) {
 }
 
 
+// IC register specifications
+const Register LoadIC::ReceiverRegister() { return edx; }
+const Register LoadIC::NameRegister() { return ecx; }
+
+
+const Register KeyedLoadIC::ReceiverRegister() {
+  return LoadIC::ReceiverRegister();
+}
+
+
+const Register KeyedLoadIC::NameRegister() { return LoadIC::NameRegister(); }
+
+
 void KeyedLoadIC::GenerateRuntimeGetProperty(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- ecx    : key