Messages in this thread | | | Date | Wed, 30 Apr 2008 19:30:45 +0200 (CEST) | From | Jan Engelhardt <> | Subject | Re: Improved Swapping Method In sort.c |
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On Wednesday 2008-04-30 19:09, Soumyadip Das Mahapatra wrote:
>Hello everybody, The swapping method (in function void u32_swap() line no.. 14 >to 16) in lib/sort.c can be improved by using the following code *(u32 *)b ^= >*(u32 *)a ^= *(u32 *)b ^= *(u32 *)a instead of the code given.
GCC is smart enough to optimize the current instructions into a bswap instruction or similar. While with xor, some are said to fail - and three xor operations are surely slower than a swap if there is a swap instruction.
Never heard of that?
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