Use strpbrk() instead of broken optimized finc_pct_or_plus()

lpereira · Aug 6, 2024 · 8f27530 · 8f27530
1 parent 22f1471
commit 8f27530
Showing 1 changed file with 1 addition and 68 deletions.
diff --git a/src/lib/lwan-request.c b/src/lib/lwan-request.c
@@ -266,73 +266,6 @@ static ALWAYS_INLINE char *identify_http_method(struct lwan_request *request,
     return NULL;
 }
 
-/* has_zero() routines stolen from the Bit Twiddling Hacks page */
-static ALWAYS_INLINE uint64_t has_zero64(uint64_t v)
-{
-    return (v - 0x0101010101010101ull) & ~v & 0x8080808080808080ull;
-}
-
-static ALWAYS_INLINE uint32_t has_zero32(uint64_t v)
-{
-    return (v - 0x01010101u) & ~v & 0x80808080u;
-}
-
-static char *find_pct_or_plus(const char *input)
-{
-    const uint64_t mask_plus64 = '+' * 0x0101010101010101ull;
-    const uint64_t mask_pct64 = '%' * 0x0101010101010101ull;
-    const uint32_t mask_plus32 = '+' * 0x01010101u;
-    const uint32_t mask_pct32 = '%' * 0x01010101u;
-    char *str = (char *)input;
-
-    while (true) {
-        uint64_t v = string_as_uint64(str);
-        uint64_t has_plus = has_zero64(v ^ mask_plus64);
-        uint64_t has_pct = has_zero64(v ^ mask_pct64);
-        uint64_t has_zero = has_zero64(v);
-        uint64_t m = LWAN_MAX(has_plus, has_pct);
-
-        if (has_zero && LWAN_MAX(has_zero, m) == has_zero) {
-            if (__builtin_ctzll(has_zero) / 8 < 4)
-                goto check_small;
-            goto check_at_least_four;
-        }
-
-        if (m) {
-            return str + __builtin_ctzll(m) / 8;
-        }
-
-        str += 8;
-    }
-
-check_at_least_four: {
-    uint32_t v = string_as_uint32(str);
-    uint32_t has_plus = has_zero32(v ^ mask_plus32);
-    uint32_t has_pct = has_zero32(v ^ mask_pct32);
-    uint32_t has_zero = has_zero32(v);
-    uint32_t m = LWAN_MAX(has_plus, has_pct);
-
-    if (has_zero && LWAN_MAX(has_zero, m) == has_zero) {
-        return NULL;
-    }
-
-    if (m) {
-        return str + __builtin_ctz(m) / 8;
-    }
-
-    str += 4;
-}
-
-check_small:
-    while (*str) {
-        if (*str == '%' || *str == '+')
-            return str;
-        str++;
-    }
-
-    return NULL;
-}
-
 __attribute__((nonnull(1))) static ssize_t url_decode(char *str)
 {
     static const unsigned char tbl1[256] = {
@@ -353,7 +286,7 @@ __attribute__((nonnull(1))) static ssize_t url_decode(char *str)
     const char *inptr = str;
     char *outptr = str;
 
-    for (char *p = find_pct_or_plus(inptr); p; p = find_pct_or_plus(inptr)) {
+    for (char *p = strpbrk(inptr, "%+"); p; p = strpbrk(inptr, "%+")) {
         const ptrdiff_t diff = p - inptr;
         if (diff)
             outptr = mempmove(outptr, inptr, (size_t)diff);