The patch titled
Subject: lib/string.c: simplify str[c]spn
has been added to the -mm tree. Its filename is
lib-stringc-simplify-strspn.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/lib-stringc-simplify-strspn.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/lib-stringc-simplify-strspn.patch
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------------------------------------------------------
From: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Subject: lib/string.c: simplify str[c]spn
Use strchr(), which makes them a lot shorter, and more obviously symmetric
in their treatment of accept/reject. It also saves a little bit of .text;
bloat-o-meter for an arm build says
Function old new delta
strcspn 92 76 -16
strspn 108 76 -32
While here, also remove a stray empty line before EXPORT_SYMBOL().
Link: https://lkml.kernel.org/r/20220328224119.3003834-2-linux@xxxxxxxxxxxxxxxxxx
Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Cc: Andy Shevchenko <andy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/string.c | 25 ++++++-------------------
1 file changed, 6 insertions(+), 19 deletions(-)
--- a/lib/string.c~lib-stringc-simplify-strspn
+++ a/lib/string.c
@@ -517,21 +517,13 @@ EXPORT_SYMBOL(strnlen);
size_t strspn(const char *s, const char *accept)
{
const char *p;
- const char *a;
- size_t count = 0;
for (p = s; *p != '\0'; ++p) {
- for (a = accept; *a != '\0'; ++a) {
- if (*p == *a)
- break;
- }
- if (*a == '\0')
- return count;
- ++count;
+ if (!strchr(accept, *p))
+ break;
}
- return count;
+ return p - s;
}
-
EXPORT_SYMBOL(strspn);
#endif
@@ -544,17 +536,12 @@ EXPORT_SYMBOL(strspn);
size_t strcspn(const char *s, const char *reject)
{
const char *p;
- const char *r;
- size_t count = 0;
for (p = s; *p != '\0'; ++p) {
- for (r = reject; *r != '\0'; ++r) {
- if (*p == *r)
- return count;
- }
- ++count;
+ if (strchr(reject, *p))
+ break;
}
- return count;
+ return p - s;
}
EXPORT_SYMBOL(strcspn);
#endif
_
Patches currently in -mm which might be from linux@xxxxxxxxxxxxxxxxxx are
lib-kconfigdebug-remove-more-config__value-indirections.patch
lib-test_stringc-add-strspn-and-strcspn-tests.patch
lib-stringc-simplify-strspn.patch
