Re: [PATCH] af_rose.c: s/suser/capable/ + micro cleanups

From: Rogier Wolff (R.E.Wolff@BitWizard.nl)
Date: Wed Aug 30 2000 - 18:26:29 EDT

  • Next message: J C Lawrence: "Reserving a (large) memory block"

    Linus Torvalds wrote:
    > actually prefer
    >
    > if (complex_test)
    > return complex_expression1;
    >
    > return complex_expression2;
    >
    > over
    >
    > return (complex_test) ? complex_expression1 : complex_expression2;

    Trade offs trade offs...

    Compare:

       int mr (unsigned int rate, int r)
       {
         int e = 16+9;
         static int round[4]={0, 0, 0xffff, 0x8000};
         if (!rate) return 0;
         for (; rate & 0xfc000000 ;rate >>= 1, e++);
         for (;!(rate & 0xfe000000);rate <<= 1, e--);
         return ((rate & ~0x02000000) | (e << (16+9)) + round[r]) >> 16;
       }

    Dense code, right? Floating point in the kernel.... Aaargh.

    Compare that with one hundred and twenty heavily commented lines in
    drivers/atm/ambassador.c ..... (A very neat driver, by the way,
    although you don't need 120 lines of code to do the above....)

                                    Roger. 

    -- 
** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2137555 **
*-- BitWizard writes Linux device drivers for any device you may have! --*
*       Common sense is the collection of                                *
******  prejudices acquired by age eighteen.   -- Albert Einstein ********
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