optimize, what optimize? opcode alignment? register reuse? is all that worth?
becasuse of a stupid compiler tiny architecture, the undefined behavior being a classic reason
thinking in brain, first in first processing, last in last processing, make sense.

还和编译优化有关，我的天，看样子还是直接传参要比执行函数靠谱，毕竟能提前控制哪个先执行，谢了，大哥

是不是说我们编写c代码不能依赖这个函数参数的执行顺序，否则就有可能掉入c陷阱中，比如我们可以先执行好函数，把结果传进去

Does that mean that we can't write c code depending on the order in which this function parameter is executed, otherwise we might fall into the c trap, for example, we can execute the function first and pass the results in

func(S1, S2, S3, S4)
OFFSET  FR2L          FL2R              PIPELINE(R2L)         PIPELINE(L2R)    PIPELINE(OOE)OPTIMIZED 2^(p)
+0x10   S4            S1                S4                    S1               ?S3?S2?...
+0x0C   S3            S2                S3                    S2               ?S2?S4?...
+0x08   S2            S3                S2                    S3               ?S1?S1?...
+0x04   S1            S4                S1                    S4               ?S4?S3?...
ebp/esp

[此贴子已经被作者于2021-9-1 12:54编辑过]

cpu: king
cpu feature: out-of-order execution
compiler: solider
compiler skill: find a way to match cpu feature

gild the lily

resolution: bypass compiler, block the ambiguity code and write asm code instead.

[此贴子已经被作者于2021-9-1 13:03编辑过]

//online parser: https://www.bccn.net/run/

#include <stdio.h>

#define Force_Sequence volatile

int main(int argc, char *argv[])
{
    Force_Sequence int i = 5;
    int j = 5;
    
    printf("[Sequenced FR2L]\n%d %d %d %d %d\n", i++, i--, ++i, --i, i);
    printf("[non-Sequenced FR2L]\n%d %d %d %d %d", j++, j--, ++j, --j, j);
    
    return 0;
}

[Sequenced FR2L]
4 5 5 4 5
[non-Sequenced FR2L]
4 5 5 5 5

https://gcc.

GCC 3.0 -> GCC 11.2 how many optimized bugs fixed? why fixed? why not declared as undefined behavior?
from pg viewer, standard undefined behavior is just an excuse, its just a bug, historical issue.
someone like it, someone dislike it, so bullshit standard.

sorry, not standard bullshit, someone likes to show the bullshit standard, the way of bullshit

看不出结果怎么算出来的，毫无道理
It makes no sense not to see how the results are calculated

thats why optimized is a bug