sys/fmt: optimize scn_u32_dec scn_u32_hex

RIOT-OS · Dec 8, 2022 · 9395feb · 9395feb
1 parent 2274a56
commit 9395feb
Showing 1 changed file with 15 additions and 22 deletions.
diff --git a/sys/fmt/fmt.c b/sys/fmt/fmt.c
@@ -469,15 +469,14 @@ uint32_t scn_u32_dec(const char *str, size_t n)
 {
  uint32_t res = 0;
 
- while (n--) {
- char c = *str++;
- if (!fmt_is_digit(c)) {
+ while( n-- ) {
+ unsigned char c = *str++;
+ unsigned d = c - '0';
+ if ( d > 9 ) {
  break;
  }
- else {
- res *= 10;
- res += (c - '0');
- }
+ res *= 10;
+ res += d;
  }
  return res;
 }
@@ -487,21 +486,15 @@ uint32_t scn_u32_hex(const char *str, size_t n)
  uint32_t res = 0;
 
  while (n--) {
- char c = *str++;
- if (!fmt_is_digit(c)) {
- if (fmt_is_upper(c)) {
- c = _to_lower(c);
- }
- if (c == '\0' || c > 'f') {
- break;
- }
- res <<= 4;
- res |= c - 'a' + 0xa;
- }
- else {
- res <<= 4;
- res |= c - '0';
- }
+ unsigned char c = *str++;
+ unsigned d;
+ if ( c - '0' <= 9 ) d = c - '0';
+ else if ( c - 'A' <= 'F' - 'A' ) d = c - 'A' + 0xa;
+ else if ( c - 'a' <= 'f' - 'a' ) d = c - 'a' + 0xa;
+ else break;
+ res <<= 4;
+ res |= d;
+
  }
  return res;
 }