// WARNING!!!
 // Very perversive code ahead!

... about a 20 lines of "very perversive" code ...

// Now you can call your grandmother back. ;)

整个函数非常棒(来自Linux的sunhme.c驱动程序，用于被Sun戏称为“快乐套餐”的网卡)。因为在那之前的卡片是“巨无霸”。明白了吗?明白了吗?)

static void happy_meal_tcvr_write(struct happy_meal *hp,
                              void __iomem *tregs, int reg,
                              unsigned short value)
{
    int tries = TCVR_WRITE_TRIES;

    ASD(("happy_meal_tcvr_write: reg=0x%02x value=%04x\n", reg, value));

    /* Welcome to Sun Microsystems, can I take your order please? */
    if (!(hp->happy_flags & HFLAG_FENABLE)) {
            happy_meal_bb_write(hp, tregs, reg, value);
            return;
    }

    /* Would you like fries with that? */
    hme_write32(hp, tregs + TCVR_FRAME,
                (FRAME_WRITE | (hp->paddr << 23) |
                 ((reg & 0xff) << 18) | (value & 0xffff)));
    while (!(hme_read32(hp, tregs + TCVR_FRAME) & 0x10000) && --tries)
            udelay(20);

    /* Anything else? */
    if (!tries)
            printk(KERN_ERR "happy meal: Aieee, transceiver MIF write bolixed\n");

    /* Fifty-two cents is your change, have a nice day. */

}

/**
 * Always returns true.
 */
public boolean isAvailable() {
    return false;
}

永远不要依赖评论……

从《雷神之锤III》的资料中，我在一些随机的帖子中偶然发现了这一点。该文件的完整源代码可以在这里找到。这是一种非常快速的求平方根倒数的方法。至于最好的评论呢?当然，这是一种常见的方法，但考虑到它附着在直线上，它的神奇之处在于它的伟大之处。

float Q_rsqrt( float number )
{
  long i;
  float x2, y;
  const float threehalfs = 1.5F;

  x2 = number * 0.5F;
  y  = number;
  i  = * ( long * ) &y;  // evil floating point bit level hacking
  i  = 0x5f3759df - ( i >> 1 ); // what the fuck?
  y  = * ( float * ) &i;
  y  = y * ( threehalfs - ( x2 * y * y ) ); // 1st iteration
  // y  = y * ( threehalfs - ( x2 * y * y ) ); // 2nd iteration, this can be removed

  #ifndef Q3_VM
  #ifdef __linux__
    assert( !isnan(y) ); // bk010122 - FPE?
  #endif
  #endif
  return y;
}

我刚刚注意到自己在写这个

// not brilliant solution, but fair enough heh.

// fix for groupid > 9 
// if groupid ever gets to 100 everything will break (again)

if (groupid < 10) {
groupid = "0" + groupid;
}