MIPS: Fix DIRECT_API_CALL_NEW and DIRECT_GETTER_CALL_NEW call.

src/mips/simulator-mips.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1369 matching lines @@
                                         int32_t arg5);
 
 // These prototypes handle the four types of FP calls.
 typedef int64_t (*SimulatorRuntimeCompareCall)(double darg0, double darg1);
 typedef double (*SimulatorRuntimeFPFPCall)(double darg0, double darg1);
 typedef double (*SimulatorRuntimeFPCall)(double darg0);
 typedef double (*SimulatorRuntimeFPIntCall)(double darg0, int32_t arg0);
 
 // This signature supports direct call in to API function native callback
 // (refer to InvocationCallback in v8.h).
+// NOTE: the O32 abi requires a0 to hold a special pointer when returning a
+// struct from the function (which is currently the case). This means we pass
+// the first argument in a1 instead of a0.
 typedef v8::Handle<v8::Value> (*SimulatorRuntimeDirectApiCall)(int32_t arg0);
+// Here, we pass the first argument in a0, because this function
+// does not return a struct.
 typedef void (*SimulatorRuntimeDirectApiCallNew)(int32_t arg0);
 
 // This signature supports direct call to accessor getter callback.
+// See comment at SimulatorRuntimeDirectApiCall.
 typedef v8::Handle<v8::Value> (*SimulatorRuntimeDirectGetterCall)(int32_t arg0,
                                                                   int32_t arg1);
+// See comment at SimulatorRuntimeDirectApiCallNew.
 typedef void (*SimulatorRuntimeDirectGetterCallNew)(int32_t arg0,
                                                     int32_t arg1);
 
 // Software interrupt instructions are used by the simulator to call into the
 // C-based V8 runtime. They are also used for debugging with simulator.
 void Simulator::SoftwareInterrupt(Instruction* instr) {
   // There are several instructions that could get us here,
   // the break_ instruction, or several variants of traps. All
   // Are "SPECIAL" class opcode, and are distinuished by function.
   int32_t func = instr->FunctionFieldRaw();
@@ skipping 129 matching lines @@
           PrintF("Returned %f\n", dresult);
           break;
         default:
           UNREACHABLE();
           break;
         }
       }
     } else if (
         redirection->type() == ExternalReference::DIRECT_API_CALL ||
         redirection->type() == ExternalReference::DIRECT_API_CALL_NEW) {
-      // See DirectCEntryStub::GenerateCall for explanation of register usage.
-      if (::v8::internal::FLAG_trace_sim) {
-        PrintF("Call to host function at %p args %08x\n",
-            reinterpret_cast<void*>(external), arg1);
-      }
       if (redirection->type() == ExternalReference::DIRECT_API_CALL) {
+        // See comment at type definition of SimulatorRuntimeDirectApiCall
+        // for explanation of register usage.
+        if (::v8::internal::FLAG_trace_sim) {
+          PrintF("Call to host function at %p args %08x\n",
+              reinterpret_cast<void*>(external), arg1);
+        }
         SimulatorRuntimeDirectApiCall target =
             reinterpret_cast<SimulatorRuntimeDirectApiCall>(external);
         v8::Handle<v8::Value> result = target(arg1);
         *(reinterpret_cast<int*>(arg0)) = reinterpret_cast<int32_t>(*result);
         set_register(v0, arg0);
       } else {
+        if (::v8::internal::FLAG_trace_sim) {
+          PrintF("Call to host function at %p args %08x\n",
+              reinterpret_cast<void*>(external), arg0);
+        }
         SimulatorRuntimeDirectApiCallNew target =
             reinterpret_cast<SimulatorRuntimeDirectApiCallNew>(external);
-        target(arg1);
+        target(arg0);
       }
     } else if (
         redirection->type() == ExternalReference::DIRECT_GETTER_CALL ||
         redirection->type() == ExternalReference::DIRECT_GETTER_CALL_NEW) {
-      // See DirectCEntryStub::GenerateCall for explanation of register usage.
-      if (::v8::internal::FLAG_trace_sim) {
-        PrintF("Call to host function at %p args %08x %08x\n",
-            reinterpret_cast<void*>(external), arg1, arg2);
-      }
       if (redirection->type() == ExternalReference::DIRECT_GETTER_CALL) {
+        // See comment at type definition of SimulatorRuntimeDirectGetterCall
+        // for explanation of register usage.
+        if (::v8::internal::FLAG_trace_sim) {
+          PrintF("Call to host function at %p args %08x %08x\n",
+              reinterpret_cast<void*>(external), arg1, arg2);
+        }
         SimulatorRuntimeDirectGetterCall target =
             reinterpret_cast<SimulatorRuntimeDirectGetterCall>(external);
         v8::Handle<v8::Value> result = target(arg1, arg2);
         *(reinterpret_cast<int*>(arg0)) = reinterpret_cast<int32_t>(*result);
         set_register(v0, arg0);
       } else {
+        if (::v8::internal::FLAG_trace_sim) {
+          PrintF("Call to host function at %p args %08x %08x\n",
+              reinterpret_cast<void*>(external), arg0, arg1);
+        }
         SimulatorRuntimeDirectGetterCallNew target =
             reinterpret_cast<SimulatorRuntimeDirectGetterCallNew>(external);
-        target(arg1, arg2);
+        target(arg0, arg1);
       }
     } else {
       SimulatorRuntimeCall target =
                   reinterpret_cast<SimulatorRuntimeCall>(external);
       if (::v8::internal::FLAG_trace_sim) {
         PrintF(
             "Call to host function at %p "
             "args %08x, %08x, %08x, %08x, %08x, %08x\n",
             FUNCTION_ADDR(target),
             arg0,
@@ skipping 1332 matching lines @@
 }
 
 
 #undef UNSUPPORTED
 
 } }  // namespace v8::internal
 
 #endif  // USE_SIMULATOR
 
 #endif  // V8_TARGET_ARCH_MIPS