Visual Studio-X64汇编编写方法

includelib ucrt.lib
includelib legacy_stdio_definitions.lib
includelib user32.lib
extern printf:proc
extern MessageBoxA:proc
.data
szFormat db "%s",0
szHello db "HelloWorld",0
szRk db "123",0
.code
start proc
	sub rsp,28h
	mov rdx,offset szHello
	mov rcx,offset szFormat
	call printf
	mov r9,0
	mov r8,offset szHello
	mov rdx,offset szRk
	mov rcx,0
	call MessageBoxA
	add rsp,28h
	ret
start endp
end 

includelib legacy_stdio_definitions.lib
includelib user32.lib
extern printf:proc
.data
	szformat db "%s\n",0
.code
Myadd proc
	sub rsp,28h
	add rcx,rdx
	mov	rax,rcx
	add rsp,28h
	ret
Myadd endp
Myprintf proc
	sub rsp,28h
	mov rdx,rcx
	lea rcx,szformat
	call printf
	add rsp,28h
	ret
Myprintf endp
end 

#include <iostream>
#include <windows.h>
EXTERN_C UINT64 Myadd(UINT64 a, UINT64 b); 
EXTERN_C void Myprintf(const char* szbuffer);
int main()
{
	UINT64 num = Myadd(1, 2);
	printf("%lld\r\n", num);
	Myprintf("hello word");
	system("pause");
	return 0;
}