lib/kstrtox.c: smaller _parse_integer()
Set "overflow" bit upon encountering it instead of postponing to the end
of the conversion. Somehow gcc unwedges itself and generates better code:
$ ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux
_parse_integer 177 139 -38
Inspired by patch from Zhaoxiu Zeng.
Link: http://lkml.kernel.org/r/20160826221920.GA1909@p183.telecom.by
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/kstrtox.c b/lib/kstrtox.c
index d8a5cf6..b8e2080 100644
--- a/lib/kstrtox.c
+++ b/lib/kstrtox.c
@@ -48,11 +48,9 @@
{
unsigned long long res;
unsigned int rv;
- int overflow;
res = 0;
rv = 0;
- overflow = 0;
while (*s) {
unsigned int val;
@@ -71,15 +69,13 @@
*/
if (unlikely(res & (~0ull << 60))) {
if (res > div_u64(ULLONG_MAX - val, base))
- overflow = 1;
+ rv |= KSTRTOX_OVERFLOW;
}
res = res * base + val;
rv++;
s++;
}
*p = res;
- if (overflow)
- rv |= KSTRTOX_OVERFLOW;
return rv;
}