diff --git a/src/x64/interface-descriptors-x64.cc b/src/x64/interface-descriptors-x64.cc
index 0913d1c..b10b522 100644
--- a/src/x64/interface-descriptors-x64.cc
+++ b/src/x64/interface-descriptors-x64.cc
@@ -114,36 +114,8 @@
 }
 
 
-void ToNumberDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // ToNumberStub invokes a function, and therefore needs a context.
-  Register registers[] = {rax};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-
 // static
-const Register ToLengthDescriptor::ReceiverRegister() { return rax; }
-
-
-// static
-const Register ToStringDescriptor::ReceiverRegister() { return rax; }
-
-
-// static
-const Register ToNameDescriptor::ReceiverRegister() { return rax; }
-
-
-// static
-const Register ToObjectDescriptor::ReceiverRegister() { return rax; }
-
-
-void NumberToStringDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {rax};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
+const Register TypeConversionDescriptor::ArgumentRegister() { return rax; }
 
 void FastCloneRegExpDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
@@ -263,6 +235,13 @@
   data->InitializePlatformSpecific(0, nullptr, nullptr);
 }
 
+#define SIMD128_ALLOC_DESC(TYPE, Type, type, lane_count, lane_type) \
+  void Allocate##Type##Descriptor::InitializePlatformSpecific(      \
+      CallInterfaceDescriptorData* data) {                          \
+    data->InitializePlatformSpecific(0, nullptr, nullptr);          \
+  }
+SIMD128_TYPES(SIMD128_ALLOC_DESC)
+#undef SIMD128_ALLOC_DESC
 
 void AllocateInNewSpaceDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
@@ -307,6 +286,12 @@
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
+void FastArrayPushDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  // stack param count needs (arg count)
+  Register registers[] = {rax};
+  data->InitializePlatformSpecific(arraysize(registers), registers);
+}
 
 void CompareDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
@@ -315,20 +300,6 @@
 }
 
 
-void CompareNilDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {rax};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-
-void ToBooleanDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {rax};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-
 void BinaryOpDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {rdx, rax};
@@ -388,21 +359,7 @@
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-
-void ApiFunctionDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      rdi,  // callee
-      rbx,  // call_data
-      rcx,  // holder
-      rdx,  // api_function_address
-      rax,  // actual number of arguments
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-
-void ApiAccessorDescriptor::InitializePlatformSpecific(
+void ApiCallbackDescriptorBase::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       rdi,  // callee