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author | Rich Felker <dalias@aerifal.cx> | 2019-10-25 12:33:17 -0400 |
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committer | Rich Felker <dalias@aerifal.cx> | 2019-10-25 12:39:40 -0400 |
commit | a11a6246c64b186c5547b9527a768a56f3d6b281 (patch) | |
tree | f651892a6075900041d0b29abd9ac12e8a60c96a /src/ctype/towctrans.c | |
parent | e8aba58ab19a18f83d7f78e80d5e4f51e7e4e8a9 (diff) | |
download | musl-a11a6246c64b186c5547b9527a768a56f3d6b281.tar.gz musl-a11a6246c64b186c5547b9527a768a56f3d6b281.tar.bz2 musl-a11a6246c64b186c5547b9527a768a56f3d6b281.tar.xz musl-a11a6246c64b186c5547b9527a768a56f3d6b281.zip |
overhaul wide character case mapping implementation
the existing implementation of case mappings was very small (typically
around 1.5k), but unmaintainable, requiring manual addition of new
case mappings with each new edition of Unicode. often, it turned out
that newly-added case mappings were not easily representable in the
existing tightly-constrained table structures, requiring new hacks to
be invented and delaying support for new characters.
the new implementation added here follows the pattern used for
character class membership, with a two-level table allowing Unicode
blocks for which no data is needed to be elided. however, rather than
single-bit data, each character maps to a one of up to 6 case-mapping
rules available to its block, where 6 is floor(cbrt(256)) and allow 3
characters to be represented per byte (vs 8 with bit tables). blocks
that would need more than 6 rules designate one as an exception and
let lookup pass into a binary search of exceptional cases for the
block.
the number 6 was chosen empirically; many blocks would be ok with 4
rules (uncased, lower, upper, possible exceptions), some even just
with 2, but the latter are rare and fitting 4 characters per byte
rather than 3 does not save significant space. moreover, somewhat
surprisingly, there are sufficiently many blocks where even 4 rules
don't suffice without a lot of exceptions (blocks where some case
pairs are laced, others offset) that originally I was looking at
supporting variable-width tables, with 1-, 2-, or 3-bit entries,
thereby allowing blocks with 8 rules. as implemented in my
experiments, that version was significantly larger and involved more
memory accesses/cache lines.
improvements in size at the expense of some performance might be
possible by utilizing iswalpha data or merging the table of case
mapping identity with alphabetic identity. these were explored
somewhat when the code was first written, and might be worth
revisiting in the future.
Diffstat (limited to 'src/ctype/towctrans.c')
-rw-r--r-- | src/ctype/towctrans.c | 345 |
1 files changed, 55 insertions, 290 deletions
diff --git a/src/ctype/towctrans.c b/src/ctype/towctrans.c index 9b91b2de..76d13769 100644 --- a/src/ctype/towctrans.c +++ b/src/ctype/towctrans.c @@ -1,308 +1,73 @@ -#include <ctype.h> -#include <stddef.h> #include <wctype.h> -#define CASEMAP(u1,u2,l) { (u1), (l)-(u1), (u2)-(u1)+1 } -#define CASELACE(u1,u2) CASEMAP((u1),(u2),(u1)+1) +static const unsigned char tab[]; -static const struct { - unsigned short upper; - signed char lower; - unsigned char len; -} casemaps[] = { - CASEMAP(0xc0,0xde,0xe0), +static const unsigned char rulebases[512]; +static const int rules[]; - CASELACE(0x0100,0x012e), - CASELACE(0x0132,0x0136), - CASELACE(0x0139,0x0147), - CASELACE(0x014a,0x0176), - CASELACE(0x0179,0x017d), +static const unsigned char exceptions[][2]; - CASELACE(0x370,0x372), - CASEMAP(0x391,0x3a1,0x3b1), - CASEMAP(0x3a3,0x3ab,0x3c3), - CASEMAP(0x400,0x40f,0x450), - CASEMAP(0x410,0x42f,0x430), +#include "casemap.h" - CASELACE(0x460,0x480), - CASELACE(0x48a,0x4be), - CASELACE(0x4c1,0x4cd), - CASELACE(0x4d0,0x50e), - - CASELACE(0x514,0x52e), - CASEMAP(0x531,0x556,0x561), - - CASELACE(0x01a0,0x01a4), - CASELACE(0x01b3,0x01b5), - CASELACE(0x01cd,0x01db), - CASELACE(0x01de,0x01ee), - CASELACE(0x01f8,0x021e), - CASELACE(0x0222,0x0232), - CASELACE(0x03d8,0x03ee), - - CASELACE(0x1e00,0x1e94), - CASELACE(0x1ea0,0x1efe), - - CASEMAP(0x1f08,0x1f0f,0x1f00), - CASEMAP(0x1f18,0x1f1d,0x1f10), - CASEMAP(0x1f28,0x1f2f,0x1f20), - CASEMAP(0x1f38,0x1f3f,0x1f30), - CASEMAP(0x1f48,0x1f4d,0x1f40), - - CASEMAP(0x1f68,0x1f6f,0x1f60), - CASEMAP(0x1f88,0x1f8f,0x1f80), - CASEMAP(0x1f98,0x1f9f,0x1f90), - CASEMAP(0x1fa8,0x1faf,0x1fa0), - CASEMAP(0x1fb8,0x1fb9,0x1fb0), - CASEMAP(0x1fba,0x1fbb,0x1f70), - CASEMAP(0x1fc8,0x1fcb,0x1f72), - CASEMAP(0x1fd8,0x1fd9,0x1fd0), - CASEMAP(0x1fda,0x1fdb,0x1f76), - CASEMAP(0x1fe8,0x1fe9,0x1fe0), - CASEMAP(0x1fea,0x1feb,0x1f7a), - CASEMAP(0x1ff8,0x1ff9,0x1f78), - CASEMAP(0x1ffa,0x1ffb,0x1f7c), - - CASEMAP(0x13f0,0x13f5,0x13f8), - CASELACE(0xa698,0xa69a), - CASELACE(0xa796,0xa79e), - - CASELACE(0x246,0x24e), - CASELACE(0x510,0x512), - CASEMAP(0x2160,0x216f,0x2170), - CASEMAP(0x2c00,0x2c2e,0x2c30), - CASELACE(0x2c67,0x2c6b), - CASELACE(0x2c80,0x2ce2), - CASELACE(0x2ceb,0x2ced), - - CASELACE(0xa640,0xa66c), - CASELACE(0xa680,0xa696), - - CASELACE(0xa722,0xa72e), - CASELACE(0xa732,0xa76e), - CASELACE(0xa779,0xa77b), - CASELACE(0xa77e,0xa786), - - CASELACE(0xa790,0xa792), - CASELACE(0xa7a0,0xa7a8), - - CASELACE(0xa7b4,0xa7b6), - - CASEMAP(0xff21,0xff3a,0xff41), - { 0,0,0 } -}; - -static const unsigned short pairs[][2] = { - { 'I', 0x0131 }, - { 'S', 0x017f }, - { 0x0130, 'i' }, - { 0x0178, 0x00ff }, - { 0x0181, 0x0253 }, - { 0x0182, 0x0183 }, - { 0x0184, 0x0185 }, - { 0x0186, 0x0254 }, - { 0x0187, 0x0188 }, - { 0x0189, 0x0256 }, - { 0x018a, 0x0257 }, - { 0x018b, 0x018c }, - { 0x018e, 0x01dd }, - { 0x018f, 0x0259 }, - { 0x0190, 0x025b }, - { 0x0191, 0x0192 }, - { 0x0193, 0x0260 }, - { 0x0194, 0x0263 }, - { 0x0196, 0x0269 }, - { 0x0197, 0x0268 }, - { 0x0198, 0x0199 }, - { 0x019c, 0x026f }, - { 0x019d, 0x0272 }, - { 0x019f, 0x0275 }, - { 0x01a6, 0x0280 }, - { 0x01a7, 0x01a8 }, - { 0x01a9, 0x0283 }, - { 0x01ac, 0x01ad }, - { 0x01ae, 0x0288 }, - { 0x01af, 0x01b0 }, - { 0x01b1, 0x028a }, - { 0x01b2, 0x028b }, - { 0x01b7, 0x0292 }, - { 0x01b8, 0x01b9 }, - { 0x01bc, 0x01bd }, - { 0x01c4, 0x01c6 }, - { 0x01c4, 0x01c5 }, - { 0x01c5, 0x01c6 }, - { 0x01c7, 0x01c9 }, - { 0x01c7, 0x01c8 }, - { 0x01c8, 0x01c9 }, - { 0x01ca, 0x01cc }, - { 0x01ca, 0x01cb }, - { 0x01cb, 0x01cc }, - { 0x01f1, 0x01f3 }, - { 0x01f1, 0x01f2 }, - { 0x01f2, 0x01f3 }, - { 0x01f4, 0x01f5 }, - { 0x01f6, 0x0195 }, - { 0x01f7, 0x01bf }, - { 0x0220, 0x019e }, - { 0x0386, 0x03ac }, - { 0x0388, 0x03ad }, - { 0x0389, 0x03ae }, - { 0x038a, 0x03af }, - { 0x038c, 0x03cc }, - { 0x038e, 0x03cd }, - { 0x038f, 0x03ce }, - { 0x0399, 0x0345 }, - { 0x0399, 0x1fbe }, - { 0x03a3, 0x03c2 }, - { 0x03f7, 0x03f8 }, - { 0x03fa, 0x03fb }, - { 0x1e60, 0x1e9b }, - { 0x1e9e, 0xdf }, - - { 0x1f59, 0x1f51 }, - { 0x1f5b, 0x1f53 }, - { 0x1f5d, 0x1f55 }, - { 0x1f5f, 0x1f57 }, - { 0x1fbc, 0x1fb3 }, - { 0x1fcc, 0x1fc3 }, - { 0x1fec, 0x1fe5 }, - { 0x1ffc, 0x1ff3 }, - - { 0x23a, 0x2c65 }, - { 0x23b, 0x23c }, - { 0x23d, 0x19a }, - { 0x23e, 0x2c66 }, - { 0x241, 0x242 }, - { 0x243, 0x180 }, - { 0x244, 0x289 }, - { 0x245, 0x28c }, - { 0x37f, 0x3f3 }, - { 0x3f4, 0x3b8 }, - { 0x3f9, 0x3f2 }, - { 0x3fd, 0x37b }, - { 0x3fe, 0x37c }, - { 0x3ff, 0x37d }, - { 0x4c0, 0x4cf }, - - { 0x2126, 0x3c9 }, - { 0x212a, 'k' }, - { 0x212b, 0xe5 }, - { 0x2132, 0x214e }, - { 0x2183, 0x2184 }, - { 0x2c60, 0x2c61 }, - { 0x2c62, 0x26b }, - { 0x2c63, 0x1d7d }, - { 0x2c64, 0x27d }, - { 0x2c6d, 0x251 }, - { 0x2c6e, 0x271 }, - { 0x2c6f, 0x250 }, - { 0x2c70, 0x252 }, - { 0x2c72, 0x2c73 }, - { 0x2c75, 0x2c76 }, - { 0x2c7e, 0x23f }, - { 0x2c7f, 0x240 }, - { 0x2cf2, 0x2cf3 }, - - { 0xa77d, 0x1d79 }, - { 0xa78b, 0xa78c }, - { 0xa78d, 0x265 }, - { 0xa7aa, 0x266 }, - - { 0x10c7, 0x2d27 }, - { 0x10cd, 0x2d2d }, - - /* bogus greek 'symbol' letters */ - { 0x376, 0x377 }, - { 0x39c, 0xb5 }, - { 0x392, 0x3d0 }, - { 0x398, 0x3d1 }, - { 0x3a6, 0x3d5 }, - { 0x3a0, 0x3d6 }, - { 0x39a, 0x3f0 }, - { 0x3a1, 0x3f1 }, - { 0x395, 0x3f5 }, - { 0x3cf, 0x3d7 }, - - { 0xa7ab, 0x25c }, - { 0xa7ac, 0x261 }, - { 0xa7ad, 0x26c }, - { 0xa7ae, 0x26a }, - { 0xa7b0, 0x29e }, - { 0xa7b1, 0x287 }, - { 0xa7b2, 0x29d }, - { 0xa7b3, 0xab53 }, - - /* special cyrillic lowercase forms */ - { 0x412, 0x1c80 }, - { 0x414, 0x1c81 }, - { 0x41e, 0x1c82 }, - { 0x421, 0x1c83 }, - { 0x422, 0x1c84 }, - { 0x422, 0x1c85 }, - { 0x42a, 0x1c86 }, - { 0x462, 0x1c87 }, - { 0xa64a, 0x1c88 }, - - { 0,0 } -}; - - -static wchar_t __towcase(wchar_t wc, int lower) +static int casemap(unsigned c, int dir) { - int i; - int lmul = 2*lower-1; - int lmask = lower-1; - /* no letters with case in these large ranges */ - if (!iswalpha(wc) - || (unsigned)wc - 0x0600 <= 0x0fff-0x0600 - || (unsigned)wc - 0x2e00 <= 0xa63f-0x2e00 - || (unsigned)wc - 0xa800 <= 0xab52-0xa800 - || (unsigned)wc - 0xabc0 <= 0xfeff-0xabc0) - return wc; - /* special case because the diff between upper/lower is too big */ - if (lower && (unsigned)wc - 0x10a0 < 0x2e) - if (wc>0x10c5 && wc != 0x10c7 && wc != 0x10cd) return wc; - else return wc + 0x2d00 - 0x10a0; - if (!lower && (unsigned)wc - 0x2d00 < 0x26) - if (wc>0x2d25 && wc != 0x2d27 && wc != 0x2d2d) return wc; - else return wc + 0x10a0 - 0x2d00; - if (lower && (unsigned)wc - 0x13a0 < 0x50) - return wc + 0xab70 - 0x13a0; - if (!lower && (unsigned)wc - 0xab70 < 0x50) - return wc + 0x13a0 - 0xab70; - for (i=0; casemaps[i].len; i++) { - int base = casemaps[i].upper + (lmask & casemaps[i].lower); - if ((unsigned)wc-base < casemaps[i].len) { - if (casemaps[i].lower == 1) - return wc + lower - ((wc-casemaps[i].upper)&1); - return wc + lmul*casemaps[i].lower; + unsigned b, x, y, v, rt, xb, xn; + int r, rd, c0 = c; + + if (c >= 0x20000) return c; + + b = c>>8; + c &= 255; + x = c/3; + y = c%3; + + /* lookup entry in two-level base-6 table */ + v = tab[tab[b]*86+x]; + static const int mt[] = { 2048, 342, 57 }; + v = (v*mt[y]>>11)%6; + + /* use the bit vector out of the tables as an index into + * a block-specific set of rules and decode the rule into + * a type and a case-mapping delta. */ + r = rules[rulebases[b]+v]; + rt = r & 255; + rd = r >> 8; + + /* rules 0/1 are simple lower/upper case with a delta. + * apply according to desired mapping direction. */ + if (rt < 2) return c0 + (rd & -(rt^dir)); + + /* binary search. endpoints of the binary search for + * this block are stored in the rule delta field. */ + xn = rd & 0xff; + xb = (unsigned)rd >> 8; + while (xn) { + unsigned try = exceptions[xb+xn/2][0]; + if (try == c) { + r = rules[exceptions[xb+xn/2][1]]; + rt = r & 255; + rd = r >> 8; + if (rt < 2) return c0 + (rd & -(rt^dir)); + /* Hard-coded for the four exceptional titlecase */ + return c0 + (dir ? -1 : 1); + } else if (try > c) { + xn /= 2; + } else { + xb += xn/2; + xn -= xn/2; } } - for (i=0; pairs[i][1-lower]; i++) { - if (pairs[i][1-lower] == wc) - return pairs[i][lower]; - } - if ((unsigned)wc - (0x10428 - 0x28*lower) < 0x28) - return wc - 0x28 + 0x50*lower; - if ((unsigned)wc - (0x104d8 - 0x28*lower) < 0x24) - return wc - 0x28 + 0x50*lower; - if ((unsigned)wc - (0x10cc0 - 0x40*lower) < 0x33) - return wc - 0x40 + 0x80*lower; - if ((unsigned)wc - (0x118c0 - 0x20*lower) < 0x20) - return wc - 0x20 + 0x40*lower; - if ((unsigned)wc - (0x1e922 - 0x22*lower) < 0x22) - return wc - 0x22 + 0x44*lower; - return wc; + return c0; } -wint_t towupper(wint_t wc) +wint_t towlower(wint_t wc) { - return (unsigned)wc < 128 ? toupper(wc) : __towcase(wc, 0); + return casemap(wc, 0); } -wint_t towlower(wint_t wc) +wint_t towupper(wint_t wc) { - return (unsigned)wc < 128 ? tolower(wc) : __towcase(wc, 1); + return casemap(wc, 1); } wint_t __towupper_l(wint_t c, locale_t l) |