使用vs2015
請看如下反彙編：
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; //即使在括號中，m++的操作也被提到了表達式的最後
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--; //逗號表達式與++ --
00007FF79F655BC4 mov eax,dword ptr [m] //逗號前
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] //逗號後
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--;//可以發現逗號後面的表達式中的加法是沒有運算的，只做了其中的前置減減和後置減減，該表達式相當於s = ++m *m++; --m + s--;
00007FF77C3A5BC4 mov eax,dword ptr [m] //逗號前面 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] //逗號後面
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); //括號與表達式，有括號時，括號內作爲一個整體的表達式 ，並且將括號中最後一部分作爲表達式運算的部分。
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] //無逗號時括號內的後置++ 被挪到表達式結尾
00007FF650985BC8 inc eax
00007FF650985BCA mov dword ptr [m],eax
s = (++m * m++, --m + b--);//可以看到括號內逗號前面的乘法是沒有運算的，由下面的彙編可以看出這個表達式等價爲++m*m++; s = --m+b--; 逗號表達式加括號的方式可以用於插裝。
00007FF73F6C5BA8 mov eax,dword ptr [m] //逗號前
00007FF73F6C5BAC inc eax
00007FF73F6C5BAE mov dword ptr [m],eax
00007FF73F6C5BB2 mov eax,dword ptr [m] //括號內 逗號前面的表達式 後置++ 被挪到提前執行了 。
00007FF73F6C5BB6 inc eax
00007FF73F6C5BB8 mov dword ptr [m],eax
00007FF73F6C5BBC mov eax,dword ptr [m] //逗號後
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--; //相當於b = ++m * m++; s = ( --m + b--) + ++b +b--;
00007FF6F36E5B98 mov eax,dword ptr [m] //逗號前
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] //逗號後
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
一個完整的表達式可以是
a = a+1；//等於號左邊的也屬於表達式內。
a++；
b= (a++,a--);//這個相當於複合表達式了，理解爲a++ ; b=a--;
表達式 是以分號或逗號結尾。
可以確定：
1、後置加加（inc）或減減（dec）是在表達式結束的時候才進行運算的。
2、前置是在表達式之前進行運算的。
3、逗號表達式實際是多個獨立的表達式。
4、括號中的逗號表達式是取逗號的最後一個表達式作爲新表達式的部分。如b= (a++,a--);中，a-- 作爲新表達式a=a--的部分。