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

src/ia32/macro-assembler-ia32.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 1970 matching lines @@
   ASSERT_EQ(0, kFlatAsciiStringMask & (kFlatAsciiStringMask << 3));
   and_(scratch1, kFlatAsciiStringMask);
   and_(scratch2, kFlatAsciiStringMask);
   lea(scratch1, Operand(scratch1, scratch2, times_8, 0));
   cmp(scratch1, kFlatAsciiStringTag | (kFlatAsciiStringTag << 3));
   j(not_equal, failure);
 }
 
 
 void MacroAssembler::PrepareCallCFunction(int num_arguments, Register scratch) {
-  // Reserve space for Isolate address which is always passed as last parameter
-  num_arguments += 1;
-
-  int frameAlignment = OS::ActivationFrameAlignment();
-  if (frameAlignment != 0) {
+  int frame_alignment = OS::ActivationFrameAlignment();
+  if (frame_alignment != 0) {
     // Make stack end at alignment and make room for num_arguments words
     // and the original value of esp.
     mov(scratch, esp);
     sub(Operand(esp), Immediate((num_arguments + 1) * kPointerSize));
-    ASSERT(IsPowerOf2(frameAlignment));
-    and_(esp, -frameAlignment);
+    ASSERT(IsPowerOf2(frame_alignment));
+    and_(esp, -frame_alignment);
     mov(Operand(esp, num_arguments * kPointerSize), scratch);
   } else {
     sub(Operand(esp), Immediate(num_arguments * kPointerSize));
   }
 }
 
 
 void MacroAssembler::CallCFunction(ExternalReference function,
                                    int num_arguments) {
   // Trashing eax is ok as it will be the return value.
   mov(Operand(eax), Immediate(function));
   CallCFunction(eax, num_arguments);
 }
 
 
 void MacroAssembler::CallCFunction(Register function,
                                    int num_arguments) {
-  // Pass current isolate address as additional parameter.
-  mov(Operand(esp, num_arguments * kPointerSize),
-      Immediate(ExternalReference::isolate_address()));
-  num_arguments += 1;
-
   // Check stack alignment.
   if (emit_debug_code()) {
     CheckStackAlignment();
   }
 
   call(Operand(function));
   if (OS::ActivationFrameAlignment() != 0) {
     mov(esp, Operand(esp, num_arguments * kPointerSize));
   } else {
-    add(Operand(esp), Immediate(num_arguments * sizeof(int32_t)));
+    add(Operand(esp), Immediate(num_arguments * kPointerSize));
   }
 }
 
 
 CodePatcher::CodePatcher(byte* address, int size)
     : address_(address), size_(size), masm_(address, size + Assembler::kGap) {
   // Create a new macro assembler pointing to the address of the code to patch.
   // The size is adjusted with kGap on order for the assembler to generate size
   // bytes of instructions without failing with buffer size constraints.
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
 
 
 CodePatcher::~CodePatcher() {
   // Indicate that code has changed.
   CPU::FlushICache(address_, size_);
 
   // Check that the code was patched as expected.
   ASSERT(masm_.pc_ == address_ + size_);
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32