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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2019-02-05 18:55:59 -0200 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2019-02-27 10:00:37 -0300 |
| commit | 457208b1e9498c1238b7af4387529388df0414c1 (patch) | |
| tree | d7310c4d50b115ceef62d4c7a1de7fff9b2657e9 | |
| parent | 30a7e2081c690dbb22022e1a7d276341b7391434 (diff) | |
| download | glibc-457208b1e9498c1238b7af4387529388df0414c1.tar.gz glibc-457208b1e9498c1238b7af4387529388df0414c1.tar.xz glibc-457208b1e9498c1238b7af4387529388df0414c1.zip | |
wcsmbs: optimize wcsnlen
This patch rewrites wcsnlen using wmemchr. The generic wmemchr already uses the strategy (loop unrolling and tail handling) and by using it it allows architectures that have optimized wmemchr (s390 and x86_64) to optimize wcsnlen as well. Checked on x86_64-linux-gnu. * wcsmbs/wcsnlen.c (__wcsnlen): Rewrite using wmemchr.
| -rw-r--r-- | ChangeLog | 2 | ||||
| -rw-r--r-- | wcsmbs/wcsnlen.c | 22 |
2 files changed, 6 insertions, 18 deletions
diff --git a/ChangeLog b/ChangeLog index 97e70aa0cb..9ab66cf735 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,7 @@ 2019-02-27 Adhemerval Zanella <adhemerval.zanella@linaro.org> + * wcsmbs/wcsnlen.c (__wcsnlen): Rewrite using wmemchr. + * wcsmbs/wcsncpy.c (__wcsncpy): Rewrite using wcsnlen, wmemset, and wmemcpy. diff --git a/wcsmbs/wcsnlen.c b/wcsmbs/wcsnlen.c index f3d5fc1fba..d38c7e4953 100644 --- a/wcsmbs/wcsnlen.c +++ b/wcsmbs/wcsnlen.c @@ -26,24 +26,10 @@ size_t __wcsnlen (const wchar_t *s, size_t maxlen) { - size_t len = 0; - - while (maxlen > 0 && s[len] != L'\0') - { - ++len; - if (--maxlen == 0 || s[len] == L'\0') - return len; - ++len; - if (--maxlen == 0 || s[len] == L'\0') - return len; - ++len; - if (--maxlen == 0 || s[len] == L'\0') - return len; - ++len; - --maxlen; - } - - return len; + const wchar_t *ret = __wmemchr (s, L'\0', maxlen); + if (ret) + maxlen = ret - s; + return maxlen; } #ifndef WCSNLEN weak_alias (__wcsnlen, wcsnlen) |