diff options
Diffstat (limited to 'inline.h')
| -rw-r--r-- | inline.h | 92 |
1 files changed, 17 insertions, 75 deletions
@@ -525,7 +525,7 @@ Perl_is_utf8_invariant_string_loc(const U8* const s, STRLEN len, const U8 ** ep) /* This looks like 0x808080... */ # define PERL_VARIANTS_WORD_MASK (PERL_COUNT_MULTIPLIER * 0x80) -# define PERL_WORDSIZE ((SSize_t) sizeof(PERL_UINTMAX_T)) +# define PERL_WORDSIZE sizeof(PERL_UINTMAX_T) # define PERL_WORD_BOUNDARY_MASK (PERL_WORDSIZE - 1) /* Evaluates to 0 if 'x' is at a word boundary; otherwise evaluates to 1, by @@ -1111,6 +1111,13 @@ S_variant_under_utf8_count(const U8* const s, const U8* const e) #endif +#ifndef PERL_IN_REGEXEC_C /* Keep these around for that file */ +# undef PERL_WORDSIZE +# undef PERL_COUNT_MULTIPLIER +# undef PERL_WORD_BOUNDARY_MASK +# undef PERL_VARIANTS_WORD_MASK +#endif + /* =for apidoc is_utf8_string @@ -2076,82 +2083,24 @@ Perl_utf8_hop_back(const U8 *s, SSize_t off, const U8 *start) { PERL_ARGS_ASSERT_UTF8_HOP_BACK; - /* XXX Note: cannot use UTF8_IS_...() too eagerly here since e.g + /* Note: cannot use UTF8_IS_...() too eagerly here since e.g * the bitops (especially ~) can create illegal UTF-8. * In other words: in Perl UTF-8 is not just for Unicode. */ assert(start <= s); assert(off <= 0); -#ifndef EBCDIC - - /* Anything but a continuation byte counts as a character: it is either a - * start byte or a single-byte character. - * - * If we are counting back a sufficient number of characters so that in the - * worst case, it will be more than 3 full words, go into full word count - * mode. XXX '3' is arbitray for purposes of testing, and should be - * adjusted based on real measurements. - * - * The worst case is if every byte is a character. */ - if (off < -3 * PERL_WORDSIZE && (s - start) > 3) { - - /* Back up to a full word boundary. */ - while (PTR2nat(s) & PERL_WORD_BOUNDARY_MASK) { - if (! UTF8_IS_CONTINUATION(*s--)) { - off++; - } - } - - /* Now look at per-word, stopping before it becomes possible that the - * next word could end the search */ - while (off < -PERL_WORDSIZE && s > start + PERL_WORDSIZE) { - s -= PERL_WORDSIZE; - - /* The number of characters in this word is the word size minus the - * number of continuation bytes; the latter being easier to figure - * out. - * - * A continuation byte has the upper 2 bits be '10', and the rest - * dont-cares. Follow this procedure: - * Continuation Start Invariant - * Original 10xxxxxx 11xxxxxx 0xxxxxxx - * Take the complement 01xxxxxx 00xxxxxx 1xxxxxxx - * Left shift by 1 10xxxxx0 0xxxxxx0 xxxxxxx0 - * AND with the original 10xxxxxx 0xxxxxx0 0xxxxxx0 - * AND with 10000000 10000000 00000000 00000000 - * (which is PERL_VARIANTS_WORD_MASK) - * Right shift by 7 00000001 00000000 00000000 - * - * This results in every bit in the word being zero except the - * lowest in each continuation byte. - * - * Multiplying by PERL_COUNT_MULTIPLIER and right shifting yields - * the count of those 1 bits (as explained in commit - * 03c1e4ab1d6ee9062fb3f94b0ba31db6698724b1). Subtracting that - * from the number of bytes in the word gives the number of - * non-continuations, i.e. the number of characters. */ - off += PERL_WORDSIZE - (((( ( (((~ (* (PERL_UINTMAX_T *) s))) << 1) - & ( (* (PERL_UINTMAX_T *) s))) - & PERL_VARIANTS_WORD_MASK) - >> (CHARBITS - 1)) - * PERL_COUNT_MULTIPLIER) - >> ((PERL_WORDSIZE - 1) * CHARBITS)); - } - - s--; - } - -#endif - - while (s > start) { + /* Note: if we know that the input is well-formed, we can do per-word + * hop-back. Commit d6ad3b72778369a84a215b498d8d60d5b03aa1af implemented + * that. But it was reverted because doing per-word has some + * start-up/tear-down overhead, so only makes sense if the distance to be + * moved is large, and core perl doesn't currently move more than a few + * characters at a time. You can reinstate it if it does become + * advantageous. */ + while (off++ && s > start) { do { s--; } while (UTF8_IS_CONTINUATION(*s) && s > start); - - if (++off >= 0) { - break; - } } GCC_DIAG_IGNORE(-Wcast-qual) @@ -2159,13 +2108,6 @@ Perl_utf8_hop_back(const U8 *s, SSize_t off, const U8 *start) GCC_DIAG_RESTORE } -#ifndef PERL_IN_REGEXEC_C /* Keep these around for that file */ -# undef PERL_WORDSIZE -# undef PERL_COUNT_MULTIPLIER -# undef PERL_WORD_BOUNDARY_MASK -# undef PERL_VARIANTS_WORD_MASK -#endif - /* =for apidoc utf8_hop_safe |