Only pass isolate parameter to C helper functions that need it.

src/arm/macro-assembler-arm.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 1781 matching lines @@
           0,
           1);
   if (result->IsFailure()) {
     return result;
   }
 
   // HandleScope limit has changed. Delete allocated extensions.
   bind(&delete_allocated_handles);
   str(r5, MemOperand(r7, kLimitOffset));
   mov(r4, r0);
-  PrepareCallCFunction(0, r5);
+  PrepareCallCFunction(1, r5);
+  mov(r0, Operand(ExternalReference::isolate_address()));
   CallCFunction(
-      ExternalReference::delete_handle_scope_extensions(isolate()), 0);
+      ExternalReference::delete_handle_scope_extensions(isolate()), 1);
   mov(r0, r4);
   jmp(&leave_exit_frame);
 
   return result;
 }
 
 
 void MacroAssembler::IllegalOperation(int num_arguments) {
   if (num_arguments > 0) {
     add(sp, sp, Operand(num_arguments * kPointerSize));
@@ skipping 975 matching lines @@
   and_(scratch, type, Operand(kFlatAsciiStringMask));
   cmp(scratch, Operand(kFlatAsciiStringTag));
   b(ne, failure);
 }
 
 static const int kRegisterPassedArguments = 4;
 
 void MacroAssembler::PrepareCallCFunction(int num_arguments, Register scratch) {
   int frame_alignment = ActivationFrameAlignment();
 
-  // Reserve space for Isolate address which is always passed as last parameter
-  num_arguments += 1;
-
   // Up to four simple arguments are passed in registers r0..r3.
   int stack_passed_arguments = (num_arguments <= kRegisterPassedArguments) ?
                                0 : num_arguments - kRegisterPassedArguments;
   if (frame_alignment > kPointerSize) {
     // Make stack end at alignment and make room for num_arguments - 4 words
     // and the original value of sp.
     mov(scratch, sp);
     sub(sp, sp, Operand((stack_passed_arguments + 1) * kPointerSize));
     ASSERT(IsPowerOf2(frame_alignment));
     and_(sp, sp, Operand(-frame_alignment));
@@ skipping 16 matching lines @@
                       ExternalReference::the_hole_value_location(isolate()),
                       scratch,
                       num_arguments);
 }
 
 
 void MacroAssembler::CallCFunctionHelper(Register function,
                                          ExternalReference function_reference,
                                          Register scratch,
                                          int num_arguments) {
-  // Push Isolate address as the last argument.
-  if (num_arguments < kRegisterPassedArguments) {
-    Register arg_to_reg[] = {r0, r1, r2, r3};
-    Register r = arg_to_reg[num_arguments];
-    mov(r, Operand(ExternalReference::isolate_address()));
-  } else {
-    int stack_passed_arguments = num_arguments - kRegisterPassedArguments;
-    // Push Isolate address on the stack after the arguments.
-    mov(scratch, Operand(ExternalReference::isolate_address()));
-    str(scratch, MemOperand(sp, stack_passed_arguments * kPointerSize));
-  }
-  num_arguments += 1;
-
   // Make sure that the stack is aligned before calling a C function unless
   // running in the simulator. The simulator has its own alignment check which
   // provides more information.
 #if defined(V8_HOST_ARCH_ARM)
   if (emit_debug_code()) {
     int frame_alignment = OS::ActivationFrameAlignment();
     int frame_alignment_mask = frame_alignment - 1;
     if (frame_alignment > kPointerSize) {
       ASSERT(IsPowerOf2(frame_alignment));
       Label alignment_as_expected;
@@ skipping 80 matching lines @@
 void CodePatcher::EmitCondition(Condition cond) {
   Instr instr = Assembler::instr_at(masm_.pc_);
   instr = (instr & ~kCondMask) | cond;
   masm_.emit(instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM