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;
 }