X64: Exit frame should use x64 ABI callee-save registers.

src/x64/codegen-x64.cc

 // Copyright 2009 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 6012 matching lines @@
 void CEntryStub::GenerateCore(MacroAssembler* masm,
                               Label* throw_normal_exception,
                               Label* throw_out_of_memory_exception,
                               StackFrame::Type frame_type,
                               bool do_gc,
                               bool always_allocate_scope) {
   // rax: result parameter for PerformGC, if any.
   // rbx: pointer to C function  (C callee-saved).
   // rbp: frame pointer  (restored after C call).
   // rsp: stack pointer  (restored after C call).
-  // rdi: number of arguments including receiver.
+  // r14: number of arguments including receiver (C callee-saved).
   // r15: pointer to the first argument (C callee-saved).
   //      This pointer is reused in LeaveExitFrame(), so it is stored in a
   //      callee-saved register.
 
   if (do_gc) {
     // Pass failure code returned from last attempt as first argument to GC.
 #ifdef __MSVC__
     __ movq(rcx, rax);  // argc.
 #else  // ! defined(__MSVC__)
     __ movq(rdi, rax);  // argv.
 #endif
     __ movq(kScratchRegister,
             FUNCTION_ADDR(Runtime::PerformGC),
             RelocInfo::RUNTIME_ENTRY);
     __ call(kScratchRegister);
   }
 
   ExternalReference scope_depth =
       ExternalReference::heap_always_allocate_scope_depth();
   if (always_allocate_scope) {
     __ movq(kScratchRegister, scope_depth);
     __ incl(Operand(kScratchRegister, 0));
   }
 
   // Call C function.
 #ifdef __MSVC__
   // MSVC passes arguments in rcx, rdx, r8, r9
-  __ movq(rcx, rdi);  // argc.
+  __ movq(rcx, r14);  // argc.
   __ movq(rdx, r15);  // argv.
 #else  // ! defined(__MSVC__)
   // GCC passes arguments in rdi, rsi, rdx, rcx, r8, r9.
-  // First argument is already in rdi.
+  __ movq(rdi, r14);  // argc.
   __ movq(rsi, r15);  // argv.
 #endif
   __ call(rbx);
   // Result is in rax - do not destroy this register!
 
   if (always_allocate_scope) {
     __ movq(kScratchRegister, scope_depth);
     __ decl(Operand(kScratchRegister, 0));
   }
 
@@ skipping 121 matching lines @@
   __ Set(rbx, 0);
   __ GetBuiltinEntry(rdx, Builtins::CALL_NON_FUNCTION);
   Handle<Code> adaptor(Builtins::builtin(Builtins::ArgumentsAdaptorTrampoline));
   __ Jump(adaptor, RelocInfo::CODE_TARGET);
 }
 
 
 void CEntryStub::GenerateBody(MacroAssembler* masm, bool is_debug_break) {
   // rax: number of arguments including receiver
   // rbx: pointer to C function  (C callee-saved)
-  // rbp: frame pointer  (restored after C call)
+  // rbp: frame pointer of calling JS frame (restored after C call)
   // rsp: stack pointer  (restored after C call)
-  // rsi: current context (C callee-saved)
-  // rdi: caller's parameter pointer pp  (C callee-saved)
+  // rsi: current context (restored)
 
   // NOTE: Invocations of builtins may return failure objects
   // instead of a proper result. The builtin entry handles
   // this by performing a garbage collection and retrying the
   // builtin once.
 
   StackFrame::Type frame_type = is_debug_break ?
       StackFrame::EXIT_DEBUG :
       StackFrame::EXIT;
 
   // Enter the exit frame that transitions from JavaScript to C++.
   __ EnterExitFrame(frame_type);
 
-  // rax: result parameter for PerformGC, if any (setup below).
-  //      Holds the result of a previous call to GenerateCore that
-  //      returned a failure. On next call, it's used as parameter
-  //      to Runtime::PerformGC.
+  // rax: Holds the context at this point, but should not be used.
+  //      On entry to code generated by GenerateCore, it must hold
+  //      a failure result if the collect_garbage argument to GenerateCore
+  //      is true.  This failure result can be the result of code
+  //      generated by a previous call to GenerateCore.  The value
+  //      of rax is then passed to Runtime::PerformGC.
   // rbx: pointer to builtin function  (C callee-saved).
-  // rbp: frame pointer  (restored after C call).
-  // rsp: stack pointer  (restored after C call).
-  // rdi: number of arguments including receiver (destroyed by C call).
-  //      The rdi register is not callee-save in Unix 64-bit ABI, so
-  //      we must treat it as volatile.
+  // rbp: frame pointer of exit frame  (restored after C call).
+  // rsp: stack pointer (restored after C call).
+  // r14: number of arguments including receiver (C callee-saved).
   // r15: argv pointer (C callee-saved).
 
   Label throw_out_of_memory_exception;
   Label throw_normal_exception;
 
   // Call into the runtime system. Collect garbage before the call if
   // running with --gc-greedy set.
   if (FLAG_gc_greedy) {
     Failure* failure = Failure::RetryAfterGC(0);
     __ movq(rax, failure, RelocInfo::NONE);
@@ skipping 697 matching lines @@
 int CompareStub::MinorKey() {
   // Encode the two parameters in a unique 16 bit value.
   ASSERT(static_cast<unsigned>(cc_) < (1 << 15));
   return (static_cast<unsigned>(cc_) << 1) | (strict_ ? 1 : 0);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal