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Diffstat (limited to 'neozip/inftrees.c')
| -rw-r--r-- | neozip/inftrees.c | 403 |
1 files changed, 403 insertions, 0 deletions
diff --git a/neozip/inftrees.c b/neozip/inftrees.c new file mode 100644 index 0000000000..1320eb988a --- /dev/null +++ b/neozip/inftrees.c @@ -0,0 +1,403 @@ +/* inftrees.c -- generate Huffman trees for efficient decoding + * Copyright (C) 1995-2024 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +#include "zbuild.h" +#include "zutil.h" +#include "inftrees.h" +#include "inflate_p.h" +#include "fallback_builtins.h" + +#if defined(__SSE2__) +# include "arch/x86/x86_intrins.h" +#elif defined(__ARM_NEON) || defined(__ARM_NEON__) +# include "arch/arm/neon_intrins.h" +#elif defined(__ALTIVEC__) +# include "arch/power/power_intrins.h" +#endif + +const char PREFIX(inflate_copyright)[] = " inflate 1.3.1 Copyright 1995-2024 Mark Adler "; +/* + If you use the zlib library in a product, an acknowledgment is welcome + in the documentation of your product. If for some reason you cannot + include such an acknowledgment, I would appreciate that you keep this + copyright string in the executable of your product. + */ + +/* Count number of codes for each code length. */ +static inline void count_lengths(uint16_t *lens, int codes, uint16_t *count) { + /* IBM...made some weird choices for VSX/VMX. Basically vec_ld has an inherent + * endianness but we don't want to force VSX to be needed */ + static const ALIGNED_(16) uint8_t one[256] = { + 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 + }; + +#if defined(__ALTIVEC__) + vector unsigned char s1 = vec_splat_u8(0); + vector unsigned char s2 = vec_splat_u8(0); + + if (codes & 1) { + s1 = vec_ld(16 * lens[0], one); + --codes; + ++lens; + } + + while (codes) { + s1 = vec_add(s1, vec_ld(16 * lens[0], one)); + s2 = vec_add(s2, vec_ld(16 * lens[1], one)); + codes -= 2; + lens += 2; + } + + vector unsigned short sum_lo = vec_add(vec_unpackh(s1), vec_unpackh(s2)); + vector unsigned short sum_hi = vec_add(vec_unpackl(s1), vec_unpackl(s2)); + + vec_st(sum_lo, 0, &count[0]); + vec_st(sum_hi, 0, &count[8]); + +#elif defined(__ARM_NEON) || defined(__ARM_NEON__) + int sym; + uint8x16_t s1 = vdupq_n_u8(0); + uint8x16_t s2 = vdupq_n_u8(0); + + if (codes & 1) { + s1 = vld1q_u8(&one[16 * lens[0]]); + } + for (sym = codes & 1; sym < codes; sym += 2) { + s1 = vaddq_u8(s1, vld1q_u8(&one[16 * lens[sym]])); + s2 = vaddq_u8(s2, vld1q_u8(&one[16 * lens[sym+1]])); + } + + vst1q_u16(&count[0], vaddl_u8(vget_low_u8(s1), vget_low_u8(s2))); + vst1q_u16(&count[8], vaddl_u8(vget_high_u8(s1), vget_high_u8(s2))); + +#elif defined(__SSE2__) + int sym; + __m128i s1 = _mm_setzero_si128(); + __m128i s2 = _mm_setzero_si128(); + + if (codes & 1) { + s1 = _mm_load_si128((const __m128i*)&one[16 * lens[0]]); + } + for (sym = codes & 1; sym < codes; sym += 2) { + s1 = _mm_add_epi8(s1, _mm_load_si128((const __m128i*)&one[16 * lens[sym]])); // vaddq_u8 + s2 = _mm_add_epi8(s2, _mm_load_si128((const __m128i*)&one[16 * lens[sym+1]])); + } + +# if defined(__AVX2__) + __m256i w1 = _mm256_cvtepu8_epi16(s1); + __m256i w2 = _mm256_cvtepu8_epi16(s2); + __m256i sum = _mm256_add_epi16(w1, w2); + + _mm256_storeu_si256((__m256i*)&count[0], sum); +# else + __m128i zero = _mm_setzero_si128(); + + __m128i s1_lo = _mm_unpacklo_epi8(s1, zero); + __m128i s2_lo = _mm_unpacklo_epi8(s2, zero); + __m128i sum_lo = _mm_add_epi16(s1_lo, s2_lo); + _mm_storeu_si128((__m128i*)&count[0], sum_lo); + + __m128i s1_hi = _mm_unpackhi_epi8(s1, zero); + __m128i s2_hi = _mm_unpackhi_epi8(s2, zero); + __m128i sum_hi = _mm_add_epi16(s1_hi, s2_hi); + _mm_storeu_si128((__m128i*)&count[8], sum_hi); +# endif +#else + int len, sym; + for (len = 0; len <= MAX_BITS; len++) + count[len] = 0; + for (sym = 0; sym < codes; sym++) + count[lens[sym]]++; + Z_UNUSED(one); +#endif +} + +/* + Build a set of tables to decode the provided canonical Huffman code. + The code lengths are lens[0..codes-1]. The result starts at *table, + whose indices are 0..2^bits-1. work is a writable array of at least + lens shorts, which is used as a work area. type is the type of code + to be generated, CODES, LENS, or DISTS. On return, zero is success, + -1 is an invalid code, and +1 means that ENOUGH isn't enough. table + on return points to the next available entry's address. bits is the + requested root table index bits, and on return it is the actual root + table index bits. It will differ if the request is greater than the + longest code or if it is less than the shortest code. + */ +int Z_INTERNAL zng_inflate_table(codetype type, uint16_t *lens, unsigned codes, + code * *table, unsigned *bits, uint16_t *work) { + unsigned len; /* a code's length in bits */ + unsigned sym; /* index of code symbols */ + unsigned min, max; /* minimum and maximum code lengths */ + unsigned root; /* number of index bits for root table */ + unsigned curr; /* number of index bits for current table */ + unsigned drop; /* code bits to drop for sub-table */ + int left; /* number of prefix codes available */ + unsigned used; /* code entries in table used */ + uint16_t rhuff; /* Reversed huffman code */ + unsigned huff; /* Huffman code */ + unsigned incr; /* for incrementing code, index */ + unsigned fill; /* index for replicating entries */ + unsigned low; /* low bits for current root entry */ + unsigned mask; /* mask for low root bits */ + code here; /* table entry for duplication */ + code *next; /* next available space in table */ + const uint16_t *base; /* base value table to use */ + const uint16_t *extra; /* extra bits table to use */ + unsigned match; /* use base and extra for symbol >= match */ + uint16_t ALIGNED_(16) count[MAX_BITS+1]; /* number of codes of each length */ + uint16_t offs[MAX_BITS+1]; /* offsets in table for each length */ + static const uint16_t lbase[31] = { /* Length codes 257..285 base */ + 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, + 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0}; + static const uint16_t lext[31] = { /* Length codes 257..285 extra */ + 16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18, + 19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 203, 77}; + static const uint16_t dbase[32] = { /* Distance codes 0..29 base */ + 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, + 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, + 8193, 12289, 16385, 24577, 0, 0}; + static const uint16_t dext[32] = { /* Distance codes 0..29 extra */ + 16, 16, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22, + 23, 23, 24, 24, 25, 25, 26, 26, 27, 27, + 28, 28, 29, 29, 64, 64}; + + /* + Process a set of code lengths to create a canonical Huffman code. The + code lengths are lens[0..codes-1]. Each length corresponds to the + symbols 0..codes-1. The Huffman code is generated by first sorting the + symbols by length from short to long, and retaining the symbol order + for codes with equal lengths. Then the code starts with all zero bits + for the first code of the shortest length, and the codes are integer + increments for the same length, and zeros are appended as the length + increases. For the deflate format, these bits are stored backwards + from their more natural integer increment ordering, and so when the + decoding tables are built in the large loop below, the integer codes + are incremented backwards. + + This routine assumes, but does not check, that all of the entries in + lens[] are in the range 0..MAXBITS. The caller must assure this. + 1..MAXBITS is interpreted as that code length. zero means that that + symbol does not occur in this code. + + The codes are sorted by computing a count of codes for each length, + creating from that a table of starting indices for each length in the + sorted table, and then entering the symbols in order in the sorted + table. The sorted table is work[], with that space being provided by + the caller. + + The length counts are used for other purposes as well, i.e. finding + the minimum and maximum length codes, determining if there are any + codes at all, checking for a valid set of lengths, and looking ahead + at length counts to determine sub-table sizes when building the + decoding tables. + */ + + /* accumulate lengths for codes (assumes lens[] all in 0..MAXBITS) */ + count_lengths(lens, codes, count); + + /* bound code lengths, force root to be within code lengths */ + root = *bits; + for (max = MAX_BITS; max >= 1; max--) + if (count[max] != 0) break; + root = MIN(root, max); + if (UNLIKELY(max == 0)) { /* no symbols to code at all */ + here.op = (unsigned char)64; /* invalid code marker */ + here.bits = (unsigned char)1; + here.val = (uint16_t)0; + *(*table)++ = here; /* make a table to force an error */ + *(*table)++ = here; + *bits = 1; + return 0; /* no symbols, but wait for decoding to report error */ + } + for (min = 1; min < max; min++) + if (count[min] != 0) break; + root = MAX(root, min); + + /* check for an over-subscribed or incomplete set of lengths */ + left = 1; + for (len = 1; len <= MAX_BITS; len++) { + left <<= 1; + left -= count[len]; + if (left < 0) return -1; /* over-subscribed */ + } + if (left > 0 && (type == CODES || max != 1)) + return -1; /* incomplete set */ + + /* generate offsets into symbol table for each length for sorting */ + offs[1] = 0; + for (len = 1; len < MAX_BITS; len++) + offs[len + 1] = offs[len] + count[len]; + + /* sort symbols by length, by symbol order within each length */ + for (sym = 0; sym < codes; sym++) + if (lens[sym] != 0) work[offs[lens[sym]]++] = (uint16_t)sym; + + /* + Create and fill in decoding tables. In this loop, the table being + filled is at next and has curr index bits. The code being used is huff + with length len. That code is converted to an index by dropping drop + bits off of the bottom. For codes where len is less than drop + curr, + those top drop + curr - len bits are incremented through all values to + fill the table with replicated entries. + + root is the number of index bits for the root table. When len exceeds + root, sub-tables are created pointed to by the root entry with an index + of the low root bits of huff. This is saved in low to check for when a + new sub-table should be started. drop is zero when the root table is + being filled, and drop is root when sub-tables are being filled. + + When a new sub-table is needed, it is necessary to look ahead in the + code lengths to determine what size sub-table is needed. The length + counts are used for this, and so count[] is decremented as codes are + entered in the tables. + + used keeps track of how many table entries have been allocated from the + provided *table space. It is checked for LENS and DIST tables against + the constants ENOUGH_LENS and ENOUGH_DISTS to guard against changes in + the initial root table size constants. See the comments in inftrees.h + for more information. + + sym increments through all symbols, and the loop terminates when + all codes of length max, i.e. all codes, have been processed. This + routine permits incomplete codes, so another loop after this one fills + in the rest of the decoding tables with invalid code markers. + */ + + /* set up for code type */ + switch (type) { + case CODES: + base = extra = work; /* dummy value--not used */ + match = 20; + break; + case LENS: + base = lbase; + extra = lext; + match = 257; + break; + default: /* DISTS */ + base = dbase; + extra = dext; + match = 0; + } + + /* initialize state for loop */ + rhuff = 0; /* starting code, reversed */ + huff = 0; /* starting code */ + sym = 0; /* starting code symbol */ + len = min; /* starting code length */ + next = *table; /* current table to fill in */ + curr = root; /* current table index bits */ + drop = 0; /* current bits to drop from code for index */ + low = (unsigned)(-1); /* trigger new sub-table when len > root */ + used = 1U << root; /* use root table entries */ + mask = used - 1; /* mask for comparing low */ + + /* check available table space */ + if ((type == LENS && used > ENOUGH_LENS) || + (type == DISTS && used > ENOUGH_DISTS)) + return 1; + + /* process all codes and make table entries */ + for (;;) { + /* create table entry */ + here.bits = (unsigned char)(len - drop); + if (LIKELY(work[sym] >= match)) { + unsigned op = extra[work[sym] - match]; + here.op = COMBINE_OP(op, here.bits); + here.bits = COMBINE_BITS(here.bits, op); + here.val = base[work[sym] - match]; + } else if (work[sym] + 1U < match) { + here.op = (unsigned char)0; + here.val = work[sym]; + } else { + here.op = (unsigned char)(32 + 64); /* end of block */ + here.val = 0; + } + + /* replicate for those indices with low len bits equal to huff */ + incr = 1U << (len - drop); + fill = 1U << curr; + min = fill; /* save offset to next table */ + do { + fill -= incr; + next[(huff >> drop) + fill] = here; + } while (fill != 0); + + /* backwards increment the len-bit code huff */ + rhuff += (0x8000u >> (len - 1)); + huff = zng_bitreverse16(rhuff); + + /* go to next symbol, update count, len */ + sym++; + if (--(count[len]) == 0) { + if (len == max) + break; + len = lens[work[sym]]; + } + + /* create new sub-table if needed */ + if (len > root && (huff & mask) != low) { + /* if first time, transition to sub-tables */ + if (drop == 0) + drop = root; + + /* increment past last table */ + next += min; /* here min is 1 << curr */ + + /* determine length of next table */ + curr = len - drop; + left = (int)(1 << curr); + while (curr + drop < max) { + left -= count[curr + drop]; + if (left <= 0) + break; + curr++; + left <<= 1; + } + + /* check for enough space */ + used += 1U << curr; + if ((type == LENS && used > ENOUGH_LENS) || (type == DISTS && used > ENOUGH_DISTS)) + return 1; + + /* point entry in root table to sub-table */ + low = huff & mask; + (*table)[low].op = (unsigned char)curr; + (*table)[low].bits = (unsigned char)root; + (*table)[low].val = (uint16_t)(next - *table); + } + } + + /* fill in remaining table entry if code is incomplete (guaranteed to have + at most one remaining entry, since if the code is incomplete, the + maximum code length that was allowed to get this far is one bit) */ + if (UNLIKELY(huff != 0)) { + here.op = (unsigned char)64; /* invalid code marker */ + here.bits = (unsigned char)(len - drop); + here.val = (uint16_t)0; + next[huff] = here; + } + + /* set return parameters */ + *table += used; + *bits = root; + return 0; +} |