Linus Torvalds <torvalds@transmeta.com> writes:
> Yeah, except if you want best code generation you should probably use
>
> static inline int fls(int x)
> {
> int bit;
> /* Only well-defined for non-zero */
> asm("bsrl %1,%0":"=r" (bit):"rm" (x));
"g" should work for the second operand too and it'll give gcc
slightly more choices with possibly better code.
But the __builtin is probably preferable if gcc supports it because
a builtin can be scheduled, inline assembly can't.
-Andi
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This archive was generated by hypermail 2b29 : Wed Apr 30 2003 - 22:00:37 EST