^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /* inffast.c -- fast decoding
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * Copyright (C) 1995-2004 Mark Adler
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * For conditions of distribution and use, see copyright notice in zlib.h
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <linux/zutil.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include "inftrees.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include "inflate.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include "inffast.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #ifndef ASMINF
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) union uu {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) unsigned short us;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) unsigned char b[2];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) /* Endian independed version */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) static inline unsigned short
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) get_unaligned16(const unsigned short *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) union uu mm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) unsigned char *b = (unsigned char *)p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) mm.b[0] = b[0];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) mm.b[1] = b[1];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) return mm.us;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) Decode literal, length, and distance codes and write out the resulting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) literal and match bytes until either not enough input or output is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) available, an end-of-block is encountered, or a data error is encountered.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) When large enough input and output buffers are supplied to inflate(), for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) example, a 16K input buffer and a 64K output buffer, more than 95% of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) inflate execution time is spent in this routine.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) Entry assumptions:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) state->mode == LEN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) strm->avail_in >= 6
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) strm->avail_out >= 258
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) start >= strm->avail_out
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) state->bits < 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) On return, state->mode is one of:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) LEN -- ran out of enough output space or enough available input
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) TYPE -- reached end of block code, inflate() to interpret next block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) BAD -- error in block data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) Notes:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) - The maximum input bits used by a length/distance pair is 15 bits for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) length code, 5 bits for the length extra, 15 bits for the distance code,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) and 13 bits for the distance extra. This totals 48 bits, or six bytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) Therefore if strm->avail_in >= 6, then there is enough input to avoid
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) checking for available input while decoding.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) - The maximum bytes that a single length/distance pair can output is 258
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) bytes, which is the maximum length that can be coded. inflate_fast()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) requires strm->avail_out >= 258 for each loop to avoid checking for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) output space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) - @start: inflate()'s starting value for strm->avail_out
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) void inflate_fast(z_streamp strm, unsigned start)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) struct inflate_state *state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) const unsigned char *in; /* local strm->next_in */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) const unsigned char *last; /* while in < last, enough input available */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) unsigned char *out; /* local strm->next_out */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) unsigned char *beg; /* inflate()'s initial strm->next_out */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) unsigned char *end; /* while out < end, enough space available */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) #ifdef INFLATE_STRICT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) unsigned dmax; /* maximum distance from zlib header */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) unsigned wsize; /* window size or zero if not using window */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) unsigned whave; /* valid bytes in the window */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) unsigned write; /* window write index */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) unsigned char *window; /* allocated sliding window, if wsize != 0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) unsigned long hold; /* local strm->hold */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) unsigned bits; /* local strm->bits */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) code const *lcode; /* local strm->lencode */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) code const *dcode; /* local strm->distcode */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) unsigned lmask; /* mask for first level of length codes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) unsigned dmask; /* mask for first level of distance codes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) code this; /* retrieved table entry */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) unsigned op; /* code bits, operation, extra bits, or */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) /* window position, window bytes to copy */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) unsigned len; /* match length, unused bytes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) unsigned dist; /* match distance */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) unsigned char *from; /* where to copy match from */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) /* copy state to local variables */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) state = (struct inflate_state *)strm->state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) in = strm->next_in;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) last = in + (strm->avail_in - 5);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) out = strm->next_out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) beg = out - (start - strm->avail_out);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) end = out + (strm->avail_out - 257);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) #ifdef INFLATE_STRICT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) dmax = state->dmax;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) wsize = state->wsize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) whave = state->whave;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) write = state->write;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) window = state->window;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) hold = state->hold;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) bits = state->bits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) lcode = state->lencode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) dcode = state->distcode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) lmask = (1U << state->lenbits) - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) dmask = (1U << state->distbits) - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) /* decode literals and length/distances until end-of-block or not enough
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) input data or output space */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) if (bits < 15) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) hold += (unsigned long)(*in++) << bits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) bits += 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) hold += (unsigned long)(*in++) << bits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) bits += 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) this = lcode[hold & lmask];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) dolen:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) op = (unsigned)(this.bits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) hold >>= op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) bits -= op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) op = (unsigned)(this.op);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) if (op == 0) { /* literal */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) *out++ = (unsigned char)(this.val);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) else if (op & 16) { /* length base */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) len = (unsigned)(this.val);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) op &= 15; /* number of extra bits */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) if (op) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) if (bits < op) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) hold += (unsigned long)(*in++) << bits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) bits += 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) len += (unsigned)hold & ((1U << op) - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) hold >>= op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) bits -= op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) if (bits < 15) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) hold += (unsigned long)(*in++) << bits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) bits += 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) hold += (unsigned long)(*in++) << bits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) bits += 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) this = dcode[hold & dmask];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) dodist:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) op = (unsigned)(this.bits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) hold >>= op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) bits -= op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) op = (unsigned)(this.op);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) if (op & 16) { /* distance base */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) dist = (unsigned)(this.val);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) op &= 15; /* number of extra bits */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) if (bits < op) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) hold += (unsigned long)(*in++) << bits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) bits += 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) if (bits < op) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) hold += (unsigned long)(*in++) << bits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) bits += 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) dist += (unsigned)hold & ((1U << op) - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) #ifdef INFLATE_STRICT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) if (dist > dmax) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) strm->msg = (char *)"invalid distance too far back";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) state->mode = BAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) hold >>= op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) bits -= op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) op = (unsigned)(out - beg); /* max distance in output */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) if (dist > op) { /* see if copy from window */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) op = dist - op; /* distance back in window */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) if (op > whave) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) strm->msg = (char *)"invalid distance too far back";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) state->mode = BAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) from = window;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) if (write == 0) { /* very common case */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) from += wsize - op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) if (op < len) { /* some from window */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) len -= op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) *out++ = *from++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) } while (--op);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) from = out - dist; /* rest from output */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) else if (write < op) { /* wrap around window */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) from += wsize + write - op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) op -= write;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) if (op < len) { /* some from end of window */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) len -= op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) *out++ = *from++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) } while (--op);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) from = window;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) if (write < len) { /* some from start of window */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) op = write;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) len -= op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) *out++ = *from++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) } while (--op);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) from = out - dist; /* rest from output */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) else { /* contiguous in window */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) from += write - op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) if (op < len) { /* some from window */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) len -= op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) *out++ = *from++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) } while (--op);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) from = out - dist; /* rest from output */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) while (len > 2) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) *out++ = *from++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) *out++ = *from++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) *out++ = *from++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) len -= 3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) if (len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) *out++ = *from++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) if (len > 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) *out++ = *from++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) unsigned short *sout;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) unsigned long loops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) from = out - dist; /* copy direct from output */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) /* minimum length is three */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) /* Align out addr */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) if (!((long)(out - 1) & 1)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) *out++ = *from++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) len--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) sout = (unsigned short *)(out);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) if (dist > 2) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) unsigned short *sfrom;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) sfrom = (unsigned short *)(from);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) loops = len >> 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) do
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) *sout++ = *sfrom++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) *sout++ = get_unaligned16(sfrom++);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) while (--loops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) out = (unsigned char *)sout;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) from = (unsigned char *)sfrom;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) } else { /* dist == 1 or dist == 2 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) unsigned short pat16;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) pat16 = *(sout-1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) if (dist == 1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) union uu mm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) /* copy one char pattern to both bytes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) mm.us = pat16;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) mm.b[0] = mm.b[1];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) pat16 = mm.us;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) loops = len >> 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) do
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) *sout++ = pat16;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) while (--loops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) out = (unsigned char *)sout;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) if (len & 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) *out++ = *from++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) else if ((op & 64) == 0) { /* 2nd level distance code */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) this = dcode[this.val + (hold & ((1U << op) - 1))];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) goto dodist;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) strm->msg = (char *)"invalid distance code";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) state->mode = BAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) else if ((op & 64) == 0) { /* 2nd level length code */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) this = lcode[this.val + (hold & ((1U << op) - 1))];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) goto dolen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) else if (op & 32) { /* end-of-block */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) state->mode = TYPE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) strm->msg = (char *)"invalid literal/length code";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) state->mode = BAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) } while (in < last && out < end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) /* return unused bytes (on entry, bits < 8, so in won't go too far back) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) len = bits >> 3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) in -= len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) bits -= len << 3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) hold &= (1U << bits) - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) /* update state and return */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) strm->next_in = in;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) strm->next_out = out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) strm->avail_in = (unsigned)(in < last ? 5 + (last - in) : 5 - (in - last));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) strm->avail_out = (unsigned)(out < end ?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 257 + (end - out) : 257 - (out - end));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) state->hold = hold;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) state->bits = bits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) inflate_fast() speedups that turned out slower (on a PowerPC G3 750CXe):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) - Using bit fields for code structure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) - Different op definition to avoid & for extra bits (do & for table bits)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) - Three separate decoding do-loops for direct, window, and write == 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) - Special case for distance > 1 copies to do overlapped load and store copy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) - Explicit branch predictions (based on measured branch probabilities)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) - Deferring match copy and interspersed it with decoding subsequent codes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) - Swapping literal/length else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) - Swapping window/direct else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) - Larger unrolled copy loops (three is about right)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) - Moving len -= 3 statement into middle of loop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) #endif /* !ASMINF */
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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