当我组装我的程序时,我看到gcc在使用-O3编译时使用jmp进行第二次pthread_wait_barrier调用.为什么会这样？

使用jmp而不是call会有什么好处.编译器在这里玩什么技巧？我猜它在这里执行尾调用优化.

顺便说一下,我在这里使用静态链接.

__attribute__ ((noinline)) void my_pthread_barrier_wait( 
    volatile int tid,pthread_barrier_t *pbar ) 
{
    pthread_barrier_wait( pbar );
    if ( tid == 0 )
    {
        if ( !rollbacked )
        {
            take_checkpoint_or_rollback( ++iter == 4 );
        }
    }
    //getcontext( &context[tid] );
    SETJMP( tid );
    asm("addr2jmp:"); 
    pthread_barrier_wait( pbar );
    // My suspicion was right,gcc was performing tail call optimization,// which was messing up with my SETJMP/LONGJMP implementation,so here I
    // put a dummy function to avoid that.
    dummy_var = dummy_func();
}