| Message ID | 20190206145850.22003-2-adhemerval.zanella@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [1/7] wcsmbs: optimize wcpcpy | expand |
If no one opposes it, I will commit this shortly. On 06/02/2019 12:58, Adhemerval Zanella wrote: > This patch rewrites wcpncpy using wcslen, wmemcpy, and wmemset. This is > similar to the optimization done on stpncpy by 48497aba8e. > > Checked on x86_64-linux-gnu. > > * wcsmbs/wcpncpy.c (__wcpcpy): Rewrite using wcslen, wmemcpy, and > wmemset. > --- > wcsmbs/wcpncpy.c | 58 +++++------------------------------------------- > 1 file changed, 6 insertions(+), 52 deletions(-) > > diff --git a/wcsmbs/wcpncpy.c b/wcsmbs/wcpncpy.c > index 7568f3b11c..7147affdd5 100644 > --- a/wcsmbs/wcpncpy.c > +++ b/wcsmbs/wcpncpy.c > @@ -17,6 +17,7 @@ > <http://www.gnu.org/licenses/>. */ > > #include <wchar.h> > +#include <string.h> > > #ifdef WCPNCPY > # define __wcpncpy WCPNCPY > @@ -27,59 +28,12 @@ > wchar_t * > __wcpncpy (wchar_t *dest, const wchar_t *src, size_t n) > { > - wint_t c; > - wchar_t *const s = dest; > - > - if (n >= 4) > - { > - size_t n4 = n >> 2; > - > - for (;;) > - { > - c = *src++; > - *dest++ = c; > - if (c == L'\0') > - break; > - c = *src++; > - *dest++ = c; > - if (c == L'\0') > - break; > - c = *src++; > - *dest++ = c; > - if (c == L'\0') > - break; > - c = *src++; > - *dest++ = c; > - if (c == L'\0') > - break; > - if (--n4 == 0) > - goto last_chars; > - } > - n -= dest - s; > - goto zero_fill; > - } > - > - last_chars: > - n &= 3; > - if (n == 0) > + size_t size = __wcsnlen (src, n); > + __wmemcpy (dest, src, size); > + dest += size; > + if (size == n) > return dest; > - > - for (;;) > - { > - c = *src++; > - --n; > - *dest++ = c; > - if (c == L'\0') > - break; > - if (n == 0) > - return dest; > - } > - > - zero_fill: > - while (n-- > 0) > - dest[n] = L'\0'; > - > - return dest - 1; > + return wmemset (dest, L'\0', (n - size)); > } > > #ifndef WCPNCPY >
diff --git a/wcsmbs/wcpncpy.c b/wcsmbs/wcpncpy.c index 7568f3b11c..7147affdd5 100644 --- a/wcsmbs/wcpncpy.c +++ b/wcsmbs/wcpncpy.c @@ -17,6 +17,7 @@ <http://www.gnu.org/licenses/>. */ #include <wchar.h> +#include <string.h> #ifdef WCPNCPY # define __wcpncpy WCPNCPY @@ -27,59 +28,12 @@ wchar_t * __wcpncpy (wchar_t *dest, const wchar_t *src, size_t n) { - wint_t c; - wchar_t *const s = dest; - - if (n >= 4) - { - size_t n4 = n >> 2; - - for (;;) - { - c = *src++; - *dest++ = c; - if (c == L'\0') - break; - c = *src++; - *dest++ = c; - if (c == L'\0') - break; - c = *src++; - *dest++ = c; - if (c == L'\0') - break; - c = *src++; - *dest++ = c; - if (c == L'\0') - break; - if (--n4 == 0) - goto last_chars; - } - n -= dest - s; - goto zero_fill; - } - - last_chars: - n &= 3; - if (n == 0) + size_t size = __wcsnlen (src, n); + __wmemcpy (dest, src, size); + dest += size; + if (size == n) return dest; - - for (;;) - { - c = *src++; - --n; - *dest++ = c; - if (c == L'\0') - break; - if (n == 0) - return dest; - } - - zero_fill: - while (n-- > 0) - dest[n] = L'\0'; - - return dest - 1; + return wmemset (dest, L'\0', (n - size)); } #ifndef WCPNCPY
This patch rewrites wcpncpy using wcslen, wmemcpy, and wmemset. This is similar to the optimization done on stpncpy by 48497aba8e. Checked on x86_64-linux-gnu. * wcsmbs/wcpncpy.c (__wcpcpy): Rewrite using wcslen, wmemcpy, and wmemset. --- wcsmbs/wcpncpy.c | 58 +++++------------------------------------------- 1 file changed, 6 insertions(+), 52 deletions(-) -- 2.17.1