[马年好!]X64的默认调用约定到底算哪一种?

[ak1946]

X64的函数调用比x86多用了几个寄存器，那么这种调用约定还是算_stdcall/_cdecl之类的吗，还是算fastcall呢?

X64平台C++代码的默认调用约定到底算是哪一种呢? 我感觉使用了4个额外寄存器的是不是就算是fastcall了?

[zwfgdlc]

前面4个参数是寄存器，依次rcx,rdx,r8,r9.之后的参数还是用栈传递

#include "stdafx.h"
#include <windows.h>

STARTUPINFOW StartInfo  = {0};
PROCESS_INFORMATION pi = {0};
TCHAR szCommandLine[MAX_PATH] = TEXT("C:\\Windows\\NOTEPAD.EXE D:\\parallel_studio_xe_2013_update4_for_windows.txt");

int _tmain(int argc, _TCHAR* argv[])
{
	StartInfo .cb = sizeof(StartInfo);

	__asm
	{
		sub rsp, 80
		lea rax, pi
		mov qword ptr [rsp+72], rax
		lea rax, StartInfo
		mov qword ptr [rsp+64], rax
		mov qword ptr [rsp+56], 0
		mov qword ptr [rsp+48], 0
		mov qword ptr [rsp+40], 0
		mov qword ptr [rsp+32], 0
		xor r9, r9
		xor r8, r8
		lea rax, szCommandLine
		mov rdx, rax
		xor rcx, rcx
		mov  rsi, qword ptr CreateProcessW
		call rsi
		add rsp, 80
	}
	//CreateProcess(0, szCommandLine, NULL, NULL, FALSE, 0, NULL, NULL, &StartInfo, &pi);
	return 0;

[oyljerry]

缺省还是cdecl