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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2019-02-05 18:43:18 -0200
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2019-02-27 10:00:37 -0300
commitddf21ec79f25410bed8ab25de5a7d3003a8d03b8 (patch)
treead13f8218f5a002d2b77425b156e1980a5246284 /wcsmbs
parent4d8015639a750aacd899e293bceeabb15bde9803 (diff)
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wcsmbs: optimize wcsncat
This patch rewrites wcsncat using wcslen, wcsnlen, and wmemcpy. This is similar to the optimization done on strncat by 3eb38795db and e80514b5a8. Checked on x86_64-linux-gnu. * wcsmbs/wcsncat.c (wcsncat): Rewrite using wcslen, wcsnlen, and wmemcpy.
Diffstat (limited to 'wcsmbs')
-rw-r--r--wcsmbs/wcsncat.c53
1 files changed, 7 insertions, 46 deletions
diff --git a/wcsmbs/wcsncat.c b/wcsmbs/wcsncat.c
index 65e9b22..cb6fe71 100644
--- a/wcsmbs/wcsncat.c
+++ b/wcsmbs/wcsncat.c
@@ -26,54 +26,15 @@
wchar_t *
WCSNCAT (wchar_t *dest, const wchar_t *src, size_t n)
{
- wchar_t c;
- wchar_t * const s = dest;
+ wchar_t *ret = dest;
- /* Find the end of DEST. */
- do
- c = *dest++;
- while (c != L'\0');
+ /* Find the end of dest. */
+ dest += __wcslen (dest);
- /* Make DEST point before next character, so we can increment
- it while memory is read (wins on pipelined cpus). */
- dest -= 2;
+ size_t ds = __wcsnlen (src, n);
- if (n >= 4)
- {
- size_t n4 = n >> 2;
- do
- {
- c = *src++;
- *++dest = c;
- if (c == L'\0')
- return s;
- c = *src++;
- *++dest = c;
- if (c == L'\0')
- return s;
- c = *src++;
- *++dest = c;
- if (c == L'\0')
- return s;
- c = *src++;
- *++dest = c;
- if (c == L'\0')
- return s;
- } while (--n4 > 0);
- n &= 3;
- }
+ dest[ds] = L'\0';
+ __wmemcpy (dest, src, ds);
- while (n > 0)
- {
- c = *src++;
- *++dest = c;
- if (c == L'\0')
- return s;
- n--;
- }
-
- if (c != L'\0')
- *++dest = L'\0';
-
- return s;
+ return ret;
}