[interpreter] Add basic framework for bytecode handler code generation.

src/compiler/linkage-impl.h

 // Copyright 2014 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.
 
 #ifndef V8_COMPILER_LINKAGE_IMPL_H_
 #define V8_COMPILER_LINKAGE_IMPL_H_
 
 #include "src/code-stubs.h"
 #include "src/compiler/osr.h"
 
@@ skipping 215 matching lines @@
         msig,                                     // machine_sig
         locations.Build(),                        // location_sig
         0,                                        // js_parameter_count
         Operator::kNoProperties,                  // properties
         LinkageTraits::CCalleeSaveRegisters(),    // callee-saved registers
         LinkageTraits::CCalleeSaveFPRegisters(),  // callee-saved fp regs
         CallDescriptor::kNoFlags,                 // flags
         "c-call");
   }
 
-  static CallDescriptor* GetInterpreterDispatchDescriptor(
-      Zone* zone, const MachineSignature* msig) {
-    DCHECK_EQ(0, msig->parameter_count());
-    LocationSignature::Builder locations(zone, msig->return_count(),
-                                         msig->parameter_count());
-    AddReturnLocations(&locations);
+  static CallDescriptor* GetInterpreterDispatchDescriptor(Zone* zone) {
+    MachineSignature::Builder types(zone, 0, 2);
+    LocationSignature::Builder locations(zone, 0, 2);
+
+    // Add registers for fixed parameters passed via interpreter dispatch.
+    DCHECK_EQ(0, Linkage::kInterpreterBytecodeParameter);

[Michael Starzinger, 2015/07/21 13:51:45]

nit: Can this be made a STATIC_ASSERT?

[rmcilroy, 2015/07/23 10:43:54]

Done.

+    types.AddParam(kMachPtr);
+    locations.AddParam(regloc(LinkageTraits::InterpreterBytecodePointerReg()));
+
+    DCHECK_EQ(1, Linkage::kInterpreterDispatchTableParameter);

[Michael Starzinger, 2015/07/21 13:51:45]

nit: Can this be made a STATIC_ASSERT?

[rmcilroy, 2015/07/23 10:43:54]

Done (also in interpreter-assembler.cc).

+    types.AddParam(kMachPtr);
+    locations.AddParam(regloc(LinkageTraits::InterpreterDispatchTableReg()));
+
     LinkageLocation target_loc = LinkageLocation::AnyRegister();
     return new (zone) CallDescriptor(          // --
         CallDescriptor::kInterpreterDispatch,  // kind
         kMachNone,                             // target MachineType
         target_loc,                            // target location
-        msig,                                  // machine_sig
+        types.Build(),                         // machine_sig
         locations.Build(),                     // location_sig
         0,                                     // js_parameter_count
         Operator::kNoProperties,               // properties
         kNoCalleeSaved,                        // callee-saved registers
         kNoCalleeSaved,                        // callee-saved fp regs
         CallDescriptor::kSupportsTailCalls,    // flags
         "interpreter-dispatch");
   }
 
   static LinkageLocation regloc(Register reg) {
@@ skipping 57 matching lines @@
     int parameter_index = 1 + index;  // skip index 0, which is the target.
     return incoming_->GetInputLocation(parameter_index);
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_LINKAGE_IMPL_H_