使用vs2015
请看如下反汇编：
int m = 2;
00007FF6C78A5B88 mov dword ptr [m],2
m++;
00007FF6C78A5B90 mov eax,dword ptr [m] //inc m
00007FF6C78A5B94 inc eax
00007FF6C78A5B96 mov dword ptr [m],eax
int s = m + m * (m++) * m; //即使在括号中，m++的操作也被提到了表达式的最后
00007FF6C78A5B9A mov eax,dword ptr [m]
00007FF6C78A5B9E imul eax,dword ptr [m]
00007FF6C78A5BA3 imul eax,dword ptr [m]
00007FF6C78A5BA8 mov ecx,dword ptr [m]
00007FF6C78A5BAC add ecx,eax
00007FF6C78A5BAE mov eax,ecx
00007FF6C78A5BB0 mov dword ptr [s],eax //set value to s
00007FF6C78A5BB7 mov eax,dword ptr [m] //inc m
00007FF6C78A5BBB inc eax
00007FF6C78A5BBD mov dword ptr [m],eax
int s = m++*m *m++ + m++;
00007FF719505B90 mov eax,dword ptr [m]
00007FF719505B94 imul eax,dword ptr [m]
00007FF719505B99 imul eax,dword ptr [m]
00007FF719505B9E add eax,dword ptr [m]
00007FF719505BA2 mov dword ptr [s],eax //set value to s
00007FF719505BA9 mov eax,dword ptr [m] //inc m
00007FF719505BAD inc eax
00007FF719505BAF mov dword ptr [m],eax
00007FF719505BB3 mov eax,dword ptr [m] //inc m
00007FF719505BB7 inc eax
00007FF719505BB9 mov dword ptr [m],eax
00007FF719505BBD mov eax,dword ptr [m] //inc m
00007FF719505BC1 inc eax
00007FF719505BC3 mov dword ptr [m],eax
int s = ++m*m *++m + ++m; //前置++
00007FF64F585B90 mov eax,dword ptr [m]
00007FF64F585B94 inc eax
00007FF64F585B96 mov dword ptr [m],eax
00007FF64F585B9A mov eax,dword ptr [m]
00007FF64F585B9E inc eax
00007FF64F585BA0 mov dword ptr [m],eax
00007FF64F585BA4 mov eax,dword ptr [m]
00007FF64F585BA8 inc eax
00007FF64F585BAA mov dword ptr [m],eax
00007FF64F585BAE mov eax,dword ptr [m]
00007FF64F585BB2 imul eax,dword ptr [m]
00007FF64F585BB7 imul eax,dword ptr [m]
00007FF64F585BBC add eax,dword ptr [m]
00007FF64F585BC0 mov dword ptr [s],eax
++s = m;
00007FF64F585BC4 mov eax,dword ptr [s]
00007FF64F585BC8 inc eax
00007FF64F585BCA mov dword ptr [s],eax
00007FF64F585BCE mov eax,dword ptr [m]
00007FF64F585BD2 mov dword ptr [s],eax
s = ++m *m++,b = --m + s--; //逗号表达式与++ --
00007FF79F655BC4 mov eax,dword ptr [m] //逗号前
00007FF79F655BC8 inc eax
00007FF79F655BCA mov dword ptr [m],eax
00007FF79F655BCE mov eax,dword ptr [m]
00007FF79F655BD2 imul eax,dword ptr [m]
00007FF79F655BD7 mov dword ptr [s],eax
00007FF79F655BDB mov eax,dword ptr [m]
00007FF79F655BDF inc eax
00007FF79F655BE1 mov dword ptr [m],eax
00007FF79F655BE5 mov eax,dword ptr [m] //逗号后
00007FF79F655BE9 dec eax
00007FF79F655BEB mov dword ptr [m],eax
00007FF79F655BEF mov eax,dword ptr [s]
00007FF79F655BF3 mov ecx,dword ptr [m]
00007FF79F655BF7 add ecx,eax
00007FF79F655BF9 mov eax,ecx
00007FF79F655BFB mov dword ptr [b],eax
00007FF79F655C02 mov eax,dword ptr [s]
00007FF79F655C06 dec eax
00007FF79F655C08 mov dword ptr [s],eax
s = ++m *m++,--m + s--;//可以发现逗号后面的表达式中的加法是没有运算的，只做了其中的前置减减和后置减减，该表达式相当于s = ++m *m++; --m + s--;
00007FF77C3A5BC4 mov eax,dword ptr [m] //逗号前面 s= ++m *m++
00007FF77C3A5BC8 inc eax
00007FF77C3A5BCA mov dword ptr [m],eax
00007FF77C3A5BCE mov eax,dword ptr [m]
00007FF77C3A5BD2 imul eax,dword ptr [m]
00007FF77C3A5BD7 mov dword ptr [s],eax
00007FF77C3A5BDB mov eax,dword ptr [m]
00007FF77C3A5BDF inc eax
00007FF77C3A5BE1 mov dword ptr [m],eax
00007FF77C3A5BE5 mov eax,dword ptr [m] //逗号后面
00007FF77C3A5BE9 dec eax
00007FF77C3A5BEB mov dword ptr [m],eax
00007FF77C3A5BEF mov eax,dword ptr [s]
00007FF77C3A5BF3 dec eax
00007FF77C3A5BF5 mov dword ptr [s],eax
s = (1, 3); //括号与表达式，有括号时，括号内作为一个整体的表达式 ，并且将括号中最后一部分作为表达式运算的部分。
00007FF73F6C5BA0 mov dword ptr [s],3
s = (1, 2, 3,5,6);
00007FF6B9F35BF9 mov dword ptr [s],6
s = (++m * m++)+1;
00007FF650985BAB mov eax,dword ptr [m]
00007FF650985BAF inc eax
00007FF650985BB1 mov dword ptr [m],eax
00007FF650985BB5 mov eax,dword ptr [m]
00007FF650985BB9 imul eax,dword ptr [m]
00007FF650985BBE inc eax
00007FF650985BC0 mov dword ptr [s],eax
00007FF650985BC4 mov eax,dword ptr [m] //无逗号时括号内的后置++ 被挪到表达式结尾
00007FF650985BC8 inc eax
00007FF650985BCA mov dword ptr [m],eax
s = (++m * m++, --m + b--);//可以看到括号内逗号前面的乘法是没有运算的，由下面的汇编可以看出这个表达式等价为++m*m++; s = --m+b--; 逗号表达式加括号的方式可以用于插装。
00007FF73F6C5BA8 mov eax,dword ptr [m] //逗号前
00007FF73F6C5BAC inc eax
00007FF73F6C5BAE mov dword ptr [m],eax
00007FF73F6C5BB2 mov eax,dword ptr [m] //括号内 逗号前面的表达式 后置++ 被挪到提前执行了 。
00007FF73F6C5BB6 inc eax
00007FF73F6C5BB8 mov dword ptr [m],eax
00007FF73F6C5BBC mov eax,dword ptr [m] //逗号后
00007FF73F6C5BC0 dec eax
00007FF73F6C5BC2 mov dword ptr [m],eax
00007FF73F6C5BC6 mov eax,dword ptr [b]
00007FF73F6C5BCA mov ecx,dword ptr [m]
00007FF73F6C5BCE add ecx,eax
00007FF73F6C5BD0 mov eax,ecx
00007FF73F6C5BD2 mov dword ptr [s],eax
00007FF73F6C5BD6 mov eax,dword ptr [b]
00007FF73F6C5BDA dec eax
00007FF73F6C5BDC mov dword ptr [b],eax
int b = 0;
00007FF6F36E5B90 mov dword ptr [b],0
int s = (b = ++m * m++, --m + b--) + ++b +b--; //相当于b = ++m * m++; s = ( --m + b--) + ++b +b--;
00007FF6F36E5B98 mov eax,dword ptr [m] //逗号前
00007FF6F36E5B9C inc eax
00007FF6F36E5B9E mov dword ptr [m],eax
00007FF6F36E5BA2 mov eax,dword ptr [m]
00007FF6F36E5BA6 imul eax,dword ptr [m]
00007FF6F36E5BAB mov dword ptr [b],eax
00007FF6F36E5BAF mov eax,dword ptr [m]
00007FF6F36E5BB3 inc eax
00007FF6F36E5BB5 mov dword ptr [m],eax
00007FF6F36E5BB9 mov eax,dword ptr [m] //逗号后
00007FF6F36E5BBD dec eax
00007FF6F36E5BBF mov dword ptr [m],eax
00007FF6F36E5BC3 mov eax,dword ptr [b]
00007FF6F36E5BC7 inc eax
00007FF6F36E5BC9 mov dword ptr [b],eax
00007FF6F36E5BCD mov eax,dword ptr [b]
00007FF6F36E5BD1 mov ecx,dword ptr [m]
00007FF6F36E5BD5 add ecx,eax
00007FF6F36E5BD7 mov eax,ecx
00007FF6F36E5BD9 add eax,dword ptr [b]
00007FF6F36E5BDD add eax,dword ptr [b]
00007FF6F36E5BE1 mov dword ptr [s],eax
00007FF6F36E5BE8 mov eax,dword ptr [b]
00007FF6F36E5BEC dec eax
00007FF6F36E5BEE mov dword ptr [b],eax
00007FF6F36E5BF2 mov eax,dword ptr [b]
00007FF6F36E5BF6 dec eax
00007FF6F36E5BF8 mov dword ptr [b],eax
一个完整的表达式可以是
a = a+1；//等于号左边的也属于表达式内。
a++；
b= (a++,a--);//这个相当于复合表达式了，理解为a++ ; b=a--;
表达式 是以分号或逗号结尾。
可以确定：
1、后置加加（inc）或减减（dec）是在表达式结束的时候才进行运算的。
2、前置是在表达式之前进行运算的。
3、逗号表达式实际是多个独立的表达式。
4、括号中的逗号表达式是取逗号的最后一个表达式作为新表达式的部分。如b= (a++,a--);中，a-- 作为新表达式a=a--的部分。