[U-Boot] [PATCH V3 2/3] lib_generic memset: fill one word at a time if possible

From: Alessandro Rubini rubini@unipv.it
If the destination is aligned, fill ulong values until possible. Then fill remaining part by bytes.
Signed-off-by: Alessandro Rubini rubini@unipv.it Acked-by: Andrea Gallo andrea.gallo@stericsson.com --- lib_generic/string.c | 22 +++++++++++++++++++--- 1 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/lib_generic/string.c b/lib_generic/string.c index 9bee79b..1575c63 100644 --- a/lib_generic/string.c +++ b/lib_generic/string.c @@ -403,10 +403,26 @@ char *strswab(const char *s) */ void * memset(void * s,int c,size_t count) { - char *xs = (char *) s; - + unsigned long *sl = (unsigned long *) s; + unsigned long cl = 0; + char *s8; + int i; + + /* do it one word at a time (32 bits or 64 bits) while possible */ + if ( ((count | (ulong)s) & (sizeof(*sl) - 1)) == 0) { + for (i=0; i<sizeof(*sl); ++i) { + cl <<= 8; + cl |= c & 0xff; + } + while (count >= sizeof(*sl)) { + *sl++ = cl; + count -= sizeof(*sl); + } + } + /* fill 8 bits at a time */ + s8 = (char *)sl; while (count--) - *xs++ = c; + *s8++ = c;
return s; }

Similar remarks to those for memcpy :
Alessandro Rubini a écrit :
From: Alessandro Rubini rubini@unipv.it
If the destination is aligned, fill ulong values until possible. Then fill remaining part by bytes.
Signed-off-by: Alessandro Rubini rubini@unipv.it Acked-by: Andrea Gallo andrea.gallo@stericsson.com
lib_generic/string.c | 22 +++++++++++++++++++--- 1 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/lib_generic/string.c b/lib_generic/string.c index 9bee79b..1575c63 100644 --- a/lib_generic/string.c +++ b/lib_generic/string.c @@ -403,10 +403,26 @@ char *strswab(const char *s) */ void * memset(void * s,int c,size_t count) {
- char *xs = (char *) s;
- unsigned long *sl = (unsigned long *) s;
Nitpick: Cast ?
+ unsigned long *sl = s;
- unsigned long cl = 0;
- char *s8;
- int i;
- /* do it one word at a time (32 bits or 64 bits) while possible */
- if ( ((count | (ulong)s) & (sizeof(*sl) - 1)) == 0) {
Remove count from or.
+ if (((ulong)s & (sizeof(*sl) - 1)) == 0) {
for (i=0; i<sizeof(*sl); ++i) {
Nitpick: for LK spaces around operators are preferred but I am not sure for U-Boot.
+ for (i = 0; i < sizeof(*sl); ++i) {
cl <<= 8;
cl |= c & 0xff;
}
while (count >= sizeof(*sl)) {
*sl++ = cl;
count -= sizeof(*sl);
}
- }
- /* fill 8 bits at a time */
- s8 = (char *)sl; while (count--)
*xs++ = c;
*s8++ = c;
return s;
}
Cheers, Chris
participants (2)
-
Alessandro Rubini
-
Chris Moore