Messages in this thread | | | From | Nathan Moinvaziri <> | Subject | Re: [PATCH] lib/string.c: Improve strcasecmp speed by not lowering if chars match | Date | Tue, 25 Oct 2022 23:27:55 +0000 |
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On 10/25/2022 12:32 PM, Christophe JAILLET wrote: > Hi, > the algorithm on github is not the same as the one posted here. > > IIUC, the one on github is wrong. If you compare 2 strings that are > the same, they will have the same length, and "if (c1 == c2) > continue;" will go one past the end of the strings. And the result > will be <0 or 0 or >0 depending the the char *after* the trailing \0. > > On the other side, the results of the benchmark on github are likely > not accurate with the algorithm posted here, because there is one more > test in each loop ("while (c1 != 0)") as long as the 2 strings are the > same. > On github this test is skipped because you will go through the "continue" > > CJ
Hi CJ,
Thanks for catching that, I had changed it at the last second. I have updated the code and the benchmarks to what I initially proposed in the patch. Results are about +/-1% from previously.
Nathan
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