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>

1 files changed, 1 insertions, 5 deletions

diff --git a/lib/kstrtox.c b/lib/kstrtox.c
index d8a5cf66c316..b8e2080c1a47 100644
--- a/lib/kstrtox.c
+++ b/lib/kstrtox.c
@@ -48,11 +48,9 @@ unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long
 {
         unsigned long long res;
         unsigned int rv;
-        int overflow;
 
         res = 0;
         rv = 0;
-        overflow = 0;
         while (*s) {
                 unsigned int val;
 
@@ -71,15 +69,13 @@ unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long
                  */
                 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;
 }