From 8cfd56d4790423499d03f09f8584e0c6de494ec7 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Tue, 11 Oct 2016 13:51:32 -0700 Subject: [PATCH] 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/kstrtox.c | 6 +----- 1 file changed, 1 insertion(+), 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; } -- 2.30.2