[PATCH 2/2] lib: kstrtox: _parse_integer: use hex_to_bin instead local conversion, and reduce branches

[zengzhaoxiu]

From: Zhaoxiu Zeng <zhaoxiu.z...@gmail.com>

Signed-off-by: Zhaoxiu Zeng <zhaoxiu.z...@gmail.com>
---
 lib/kstrtox.c | 22 +++++-----------------
 1 file changed, 5 insertions(+), 17 deletions(-)

diff --git a/lib/kstrtox.c b/lib/kstrtox.c
index d8a5cf6..70d3374 100644
--- a/lib/kstrtox.c
+++ b/lib/kstrtox.c
@@ -48,38 +48,26 @@ unsigned int _parse_integer(const char *s, unsigned int 
base, unsigned long long
 {
        unsigned long long res;
        unsigned int rv;
-       int overflow;
+       unsigned int overflow;
+       unsigned int val;
 
        res = 0;
        rv = 0;
        overflow = 0;
-       while (*s) {
-               unsigned int val;
-
-               if ('0' <= *s && *s <= '9')
-                       val = *s - '0';
-               else if ('a' <= _tolower(*s) && _tolower(*s) <= 'f')
-                       val = _tolower(*s) - 'a' + 10;
-               else
-                       break;
-
-               if (val >= base)
-                       break;
+       while ((val = hex_to_bin(*s++)) < base) {
                /*
                 * Check for overflow only if we are within range of
                 * it in the max base we support (16)
                 */
                if (unlikely(res & (~0ull << 60))) {
                        if (res > div_u64(ULLONG_MAX - val, base))
-                               overflow = 1;
+                               overflow = KSTRTOX_OVERFLOW;
                }
                res = res * base + val;
                rv++;
-               s++;
        }
        *p = res;
-       if (overflow)
-               rv |= KSTRTOX_OVERFLOW;
+       rv |= overflow;
        return rv;
 }
 
-- 
2.7.4