Multiple stubs can point to the same calling convention.

src/x64/interface-descriptors-x64.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_X64
 
 #include "src/interface-descriptors.h"
 
 namespace v8 {
 namespace internal {
 
 const Register InterfaceDescriptor::ContextRegister() { return rsi; }
 
 
 void CallDescriptors::InitializeForIsolate(Isolate* isolate) {
+  InitializeForIsolateAllPlatforms(isolate);
+
+  {
+    CallInterfaceDescriptor* descriptor =
+        isolate->call_descriptor(CallDescriptorKey::FastNewClosureCall);
+    Register registers[] = {rsi, rbx};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+  {
+    CallInterfaceDescriptor* descriptor =
+        isolate->call_descriptor(CallDescriptorKey::FastNewContextCall);
+    Register registers[] = {rsi, rdi};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+  {
+    CallInterfaceDescriptor* descriptor =
+        isolate->call_descriptor(CallDescriptorKey::ToNumberCall);
+    // ToNumberStub invokes a function, and therefore needs a context.
+    Register registers[] = {rsi, rax};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+  {
+    CallInterfaceDescriptor* descriptor =
+        isolate->call_descriptor(CallDescriptorKey::NumberToStringCall);
+    Register registers[] = {rsi, rax};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+  {
+    CallInterfaceDescriptor* descriptor =
+        isolate->call_descriptor(CallDescriptorKey::FastCloneShallowArrayCall);
+    Register registers[] = {rsi, rax, rbx, rcx};
+    Representation representations[] = {
+        Representation::Tagged(), Representation::Tagged(),
+        Representation::Smi(), Representation::Tagged()};
+    descriptor->Initialize(arraysize(registers), registers, representations);
+  }
+  {
+    CallInterfaceDescriptor* descriptor =
+        isolate->call_descriptor(CallDescriptorKey::FastCloneShallowObjectCall);
+    Register registers[] = {rsi, rax, rbx, rcx, rdx};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+  {
+    CallInterfaceDescriptor* descriptor =
+        isolate->call_descriptor(CallDescriptorKey::CreateAllocationSiteCall);
+    Register registers[] = {rsi, rbx, rdx};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+  {
+    CallInterfaceDescriptor* descriptor =
+        isolate->call_descriptor(CallDescriptorKey::CallFunctionCall);
+    Register registers[] = {rsi, rdi};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+  {
+    CallInterfaceDescriptor* descriptor =
+        isolate->call_descriptor(CallDescriptorKey::CallConstructCall);
+    // rax : number of arguments
+    // rbx : feedback vector
+    // rdx : (only if rbx is not the megamorphic symbol) slot in feedback
+    //       vector (Smi)
+    // rdi : constructor function
+    // TODO(turbofan): So far we don't gather type feedback and hence skip the
+    // slot parameter, but ArrayConstructStub needs the vector to be undefined.
+    Register registers[] = {rsi, rax, rdi, rbx};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+  {
+    CallInterfaceDescriptor* descriptor =
+        isolate->call_descriptor(CallDescriptorKey::RegExpConstructResultCall);
+    Register registers[] = {rsi, rcx, rbx, rax};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+  {
+    CallInterfaceDescriptor* descriptor =
+        isolate->call_descriptor(CallDescriptorKey::TransitionElementsKindCall);
+    Register registers[] = {rsi, rax, rbx};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+  {
+    CallInterfaceDescriptor* descriptor = isolate->call_descriptor(
+        CallDescriptorKey::ArrayConstructorConstantArgCountCall);
+    // register state
+    // rax -- number of arguments
+    // rdi -- function
+    // rbx -- allocation site with elements kind
+    Register registers[] = {rsi, rdi, rbx};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+  {
+    CallInterfaceDescriptor* descriptor =
+        isolate->call_descriptor(CallDescriptorKey::ArrayConstructorCall);
+    // stack param count needs (constructor pointer, and single argument)
+    Register registers[] = {rsi, rdi, rbx, rax};
+    Representation representations[] = {
+        Representation::Tagged(), Representation::Tagged(),
+        Representation::Tagged(), Representation::Integer32()};
+    descriptor->Initialize(arraysize(registers), registers, representations);
+  }
+  {
+    CallInterfaceDescriptor* descriptor = isolate->call_descriptor(
+        CallDescriptorKey::InternalArrayConstructorConstantArgCountCall);
+    // register state
+    // rsi -- context
+    // rax -- number of arguments
+    // rdi -- constructor function
+    Register registers[] = {rsi, rdi};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+  {
+    CallInterfaceDescriptor* descriptor = isolate->call_descriptor(
+        CallDescriptorKey::InternalArrayConstructorCall);
+    // stack param count needs (constructor pointer, and single argument)
+    Register registers[] = {rsi, rdi, rax};
+    Representation representations[] = {Representation::Tagged(),
+                                        Representation::Tagged(),
+                                        Representation::Integer32()};
+    descriptor->Initialize(arraysize(registers), registers, representations);
+  }
+  {
+    CallInterfaceDescriptor* descriptor =
+        isolate->call_descriptor(CallDescriptorKey::CompareNilCall);
+    Register registers[] = {rsi, rax};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+  {
+    CallInterfaceDescriptor* descriptor =
+        isolate->call_descriptor(CallDescriptorKey::ToBooleanCall);
+    Register registers[] = {rsi, rax};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+  {
+    CallInterfaceDescriptor* descriptor =
+        isolate->call_descriptor(CallDescriptorKey::BinaryOpCall);
+    Register registers[] = {rsi, rdx, rax};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+  {
+    CallInterfaceDescriptor* descriptor = isolate->call_descriptor(
+        CallDescriptorKey::BinaryOpWithAllocationSiteCall);
+    Register registers[] = {rsi, rcx, rdx, rax};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+  {
+    CallInterfaceDescriptor* descriptor =
+        isolate->call_descriptor(CallDescriptorKey::StringAddCall);
+    Register registers[] = {rsi, rdx, rax};
+    descriptor->Initialize(arraysize(registers), registers, NULL);
+  }
+
   {
     CallInterfaceDescriptor* descriptor =
         isolate->call_descriptor(CallDescriptorKey::ArgumentAdaptorCall);
     Register registers[] = {
         rsi,  // context
         rdi,  // JSFunction
         rax,  // actual number of arguments
         rbx,  // expected number of arguments
     };
     Representation representations[] = {
@@ skipping 60 matching lines @@
         Representation::Tagged(),    // holder
         Representation::External(),  // api_function_address
     };
     descriptor->Initialize(arraysize(registers), registers, representations);
   }
 }
 }
 }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64