base32/64: code shrink
function old new delta decode_base64 178 173 -5 decode_base32 217 186 -31 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-36) Total: -36 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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@ -92,8 +92,8 @@ const char* FAST_FUNC decode_base64(char **pp_dst, const char *src)
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{
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{
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char *dst = *pp_dst;
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char *dst = *pp_dst;
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unsigned ch = 0;
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unsigned ch = 0;
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unsigned t;
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int i = 0;
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int i = 0;
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int t;
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while ((t = (unsigned char)*src) != '\0') {
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while ((t = (unsigned char)*src) != '\0') {
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src++;
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src++;
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@ -117,11 +117,11 @@ const char* FAST_FUNC decode_base64(char **pp_dst, const char *src)
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continue;
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continue;
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ch = (ch << 6) | t;
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ch = (ch << 6) | t;
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if (++i == 4) {
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i = (i + 1) & 3;
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if (i == 0) {
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*dst++ = (char) (ch >> 16);
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*dst++ = (char) (ch >> 16);
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*dst++ = (char) (ch >> 8);
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*dst++ = (char) (ch >> 8);
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*dst++ = (char) ch;
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*dst++ = (char) ch;
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i = 0;
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if (ch & 0x1000000) { /* was last input char '='? */
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if (ch & 0x1000000) { /* was last input char '='? */
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dst--;
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dst--;
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if (ch & (0x1000000 << 6)) /* was it "=="? */
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if (ch & (0x1000000 << 6)) /* was it "=="? */
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@ -140,9 +140,9 @@ const char* FAST_FUNC decode_base64(char **pp_dst, const char *src)
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const char* FAST_FUNC decode_base32(char **pp_dst, const char *src)
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const char* FAST_FUNC decode_base32(char **pp_dst, const char *src)
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{
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{
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char *dst = *pp_dst;
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char *dst = *pp_dst;
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uint64_t ch = 0;
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int64_t ch = 0;
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unsigned t;
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int i = 0;
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int i = 0;
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int t;
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while ((t = (unsigned char)*src) != '\0') {
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while ((t = (unsigned char)*src) != '\0') {
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src++;
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src++;
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@ -150,44 +150,52 @@ const char* FAST_FUNC decode_base32(char **pp_dst, const char *src)
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/* "if" forest is faster than strchr(bb_uuenc_tbl_base32, t) */
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/* "if" forest is faster than strchr(bb_uuenc_tbl_base32, t) */
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if (t >= '2' && t <= '7')
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if (t >= '2' && t <= '7')
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t = t - '2' + 26;
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t = t - '2' + 26;
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else if ((t|0x20) >= 'a' && (t|0x20) <= 'z')
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t = (t|0x20) - 'a';
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else if (t == '=' && i > 1)
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else if (t == '=' && i > 1)
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t = 0;
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t = 0;
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else
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else {
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t = (t | 0x20) - 'a';
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if (t > 25)
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//TODO: add BASE64_FLAG_foo to die on bad char?
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//TODO: add BASE64_FLAG_foo to die on bad char?
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continue;
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continue;
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ch = (ch << 5) | (unsigned)t; /* cast prevents pointless sign-extension of t */
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if (++i == 8) {
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/* testcase:
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* echo ' 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18' | base32 | base32 -d
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* IOW, decoding of
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* EAYSAMRAGMQDIIBVEA3CANZAHAQDSIBRGAQDCMJAGEZCAMJTEAYTIIBRGUQDCNRAGE3SAMJYBI==
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* ====
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* should correctly stitch together the tail.
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*/
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if (t == 0) {
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const char *s = src;
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while (*--s == '=')
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t--;
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}
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}
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ch = (ch << 5) | t;
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i = (i + 1) & 7;
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if (i == 0) {
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*dst++ = (char) (ch >> 32);
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*dst++ = (char) (ch >> 32);
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if (src[-1] == '=') /* was last input char '='? */
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goto tail;
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*dst++ = (char) (ch >> 24);
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*dst++ = (char) (ch >> 24);
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*dst++ = (char) (ch >> 16);
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*dst++ = (char) (ch >> 16);
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*dst++ = (char) (ch >> 8);
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*dst++ = (char) (ch >> 8);
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*dst++ = (char) ch;
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*dst++ = (char) ch;
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i = 0;
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if (t < 0) /* was last input char '='? */
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break;
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}
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}
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}
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}
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if (t < 0) /* was last input char '='? */
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/* -t is the count of =, must be 1, 3, 4 or 6 */
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dst -= (-t + 1) * 2 / 3; /* discard last 1, 2, 3 or 4 bytes */
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*pp_dst = dst;
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*pp_dst = dst;
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/* i is zero here if full 8-char block was decoded */
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/* i is zero here if full 8-char block was decoded */
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return src - i;
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return src - i;
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tail:
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{
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const char *s = src;
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while (*--s == '=')
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i++;
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/* Why duplicate the below code? Testcase:
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* echo ' 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18' | base32 | base32 -d
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* IOW, decoding of
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* EAYSAMRAGMQDIIBVEA3CANZAHAQDSIBRGAQDCMJAGEZCAMJTEAYTIIBRGUQDCNRAGE3SAMJYBI==
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* ====
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* must correctly stitch together the tail, must not overwrite
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* the tail before it is analyzed! (we can be decoding in-place)
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* Else testcase fails, prints trailing extra NUL bytes.
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*/
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*dst++ = (char) (ch >> 24);
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*dst++ = (char) (ch >> 16);
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*dst++ = (char) (ch >> 8);
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*dst++ = (char) ch;
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dst -= (i+1) * 2 / 3; /* discard last 1, 2, 3 or 4 bytes */
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}
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*pp_dst = dst;
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return src;
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}
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}
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#endif
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#endif
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