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1 /* inffas86.c is a hand tuned assembler version of
2  *
3  * inffast.c -- fast decoding
4  * Copyright (C) 1995-2003 Mark Adler
5  * For conditions of distribution and use, see copyright notice in zlib.h
6  *
7  * Copyright (C) 2003 Chris Anderson <christop@charm.net>
8  * Please use the copyright conditions above.
9  *
10  * Dec-29-2003 -- I added AMD64 inflate asm support.  This version is also
11  * slightly quicker on x86 systems because, instead of using rep movsb to copy
12  * data, it uses rep movsw, which moves data in 2-byte chunks instead of single
13  * bytes.  I've tested the AMD64 code on a Fedora Core 1 + the x86_64 updates
14  * from http://fedora.linux.duke.edu/fc1_x86_64
15  * which is running on an Athlon 64 3000+ / Gigabyte GA-K8VT800M system with
16  * 1GB ram.  The 64-bit version is about 4% faster than the 32-bit version,
17  * when decompressing mozilla-source-1.3.tar.gz.
18  *
19  * Mar-13-2003 -- Most of this is derived from inffast.S which is derived from
20  * the gcc -S output of zlib-1.2.0/inffast.c.  Zlib-1.2.0 is in beta release at
21  * the moment.  I have successfully compiled and tested this code with gcc2.96,
22  * gcc3.2, icc5.0, msvc6.0.  It is very close to the speed of inffast.S
23  * compiled with gcc -DNO_MMX, but inffast.S is still faster on the P3 with MMX
24  * enabled.  I will attempt to merge the MMX code into this version.  Newer
25  * versions of this and inffast.S can be found at
26  * http://www.eetbeetee.com/zlib/ and http://www.charm.net/~christop/zlib/
27  */
28 
29 #include "zutil.h"
30 #include "inftrees.h"
31 #include "inflate.h"
32 #include "inffast.h"
33 
34 /* Mark Adler's comments from inffast.c: */
35 
36 /*
37    Decode literal, length, and distance codes and write out the resulting
38    literal and match bytes until either not enough input or output is
39    available, an end-of-block is encountered, or a data error is encountered.
40    When large enough input and output buffers are supplied to inflate(), for
41    example, a 16K input buffer and a 64K output buffer, more than 95% of the
42    inflate execution time is spent in this routine.
43 
44    Entry assumptions:
45 
46         state->mode == LEN
47         strm->avail_in >= 6
48         strm->avail_out >= 258
49         start >= strm->avail_out
50         state->bits < 8
51 
52    On return, state->mode is one of:
53 
54         LEN -- ran out of enough output space or enough available input
55         TYPE -- reached end of block code, inflate() to interpret next block
56         BAD -- error in block data
57 
58    Notes:
59 
60     - The maximum input bits used by a length/distance pair is 15 bits for the
61       length code, 5 bits for the length extra, 15 bits for the distance code,
62       and 13 bits for the distance extra.  This totals 48 bits, or six bytes.
63       Therefore if strm->avail_in >= 6, then there is enough input to avoid
64       checking for available input while decoding.
65 
66     - The maximum bytes that a single length/distance pair can output is 258
67       bytes, which is the maximum length that can be coded.  inflate_fast()
68       requires strm->avail_out >= 258 for each loop to avoid checking for
69       output space.
70  */
inflate_fast(strm,start)71 void inflate_fast(strm, start)
72 z_streamp strm;
73 unsigned start;         /* inflate()'s starting value for strm->avail_out */
74 {
75     struct inflate_state FAR *state;
76     struct inffast_ar {
77 /* 64   32                               x86  x86_64 */
78 /* ar offset                              register */
79 /*  0    0 */ void *esp;                /* esp save */
80 /*  8    4 */ void *ebp;                /* ebp save */
81 /* 16    8 */ unsigned char FAR *in;    /* esi rsi  local strm->next_in */
82 /* 24   12 */ unsigned char FAR *last;  /*     r9   while in < last */
83 /* 32   16 */ unsigned char FAR *out;   /* edi rdi  local strm->next_out */
84 /* 40   20 */ unsigned char FAR *beg;   /*          inflate()'s init next_out */
85 /* 48   24 */ unsigned char FAR *end;   /*     r10  while out < end */
86 /* 56   28 */ unsigned char FAR *window;/*          size of window, wsize!=0 */
87 /* 64   32 */ code const FAR *lcode;    /* ebp rbp  local strm->lencode */
88 /* 72   36 */ code const FAR *dcode;    /*     r11  local strm->distcode */
89 /* 80   40 */ unsigned long hold;       /* edx rdx  local strm->hold */
90 /* 88   44 */ unsigned bits;            /* ebx rbx  local strm->bits */
91 /* 92   48 */ unsigned wsize;           /*          window size */
92 /* 96   52 */ unsigned write;           /*          window write index */
93 /*100   56 */ unsigned lmask;           /*     r12  mask for lcode */
94 /*104   60 */ unsigned dmask;           /*     r13  mask for dcode */
95 /*108   64 */ unsigned len;             /*     r14  match length */
96 /*112   68 */ unsigned dist;            /*     r15  match distance */
97 /*116   72 */ unsigned status;          /*          set when state chng*/
98     } ar;
99 
100 #if defined( __GNUC__ ) && defined( __amd64__ ) && ! defined( __i386 )
101 #define PAD_AVAIL_IN 6
102 #define PAD_AVAIL_OUT 258
103 #else
104 #define PAD_AVAIL_IN 5
105 #define PAD_AVAIL_OUT 257
106 #endif
107 
108     /* copy state to local variables */
109     state = (struct inflate_state FAR *)strm->state;
110     ar.in = strm->next_in;
111     ar.last = ar.in + (strm->avail_in - PAD_AVAIL_IN);
112     ar.out = strm->next_out;
113     ar.beg = ar.out - (start - strm->avail_out);
114     ar.end = ar.out + (strm->avail_out - PAD_AVAIL_OUT);
115     ar.wsize = state->wsize;
116     ar.write = state->wnext;
117     ar.window = state->window;
118     ar.hold = state->hold;
119     ar.bits = state->bits;
120     ar.lcode = state->lencode;
121     ar.dcode = state->distcode;
122     ar.lmask = (1U << state->lenbits) - 1;
123     ar.dmask = (1U << state->distbits) - 1;
124 
125     /* decode literals and length/distances until end-of-block or not enough
126        input data or output space */
127 
128     /* align in on 1/2 hold size boundary */
129     while (((unsigned long)(void *)ar.in & (sizeof(ar.hold) / 2 - 1)) != 0) {
130         ar.hold += (unsigned long)*ar.in++ << ar.bits;
131         ar.bits += 8;
132     }
133 
134 #if defined( __GNUC__ ) && defined( __amd64__ ) && ! defined( __i386 )
135     __asm__ __volatile__ (
136 "        leaq    %0, %%rax\n"
137 "        movq    %%rbp, 8(%%rax)\n"       /* save regs rbp and rsp */
138 "        movq    %%rsp, (%%rax)\n"
139 "        movq    %%rax, %%rsp\n"          /* make rsp point to &ar */
140 "        movq    16(%%rsp), %%rsi\n"      /* rsi  = in */
141 "        movq    32(%%rsp), %%rdi\n"      /* rdi  = out */
142 "        movq    24(%%rsp), %%r9\n"       /* r9   = last */
143 "        movq    48(%%rsp), %%r10\n"      /* r10  = end */
144 "        movq    64(%%rsp), %%rbp\n"      /* rbp  = lcode */
145 "        movq    72(%%rsp), %%r11\n"      /* r11  = dcode */
146 "        movq    80(%%rsp), %%rdx\n"      /* rdx  = hold */
147 "        movl    88(%%rsp), %%ebx\n"      /* ebx  = bits */
148 "        movl    100(%%rsp), %%r12d\n"    /* r12d = lmask */
149 "        movl    104(%%rsp), %%r13d\n"    /* r13d = dmask */
150                                           /* r14d = len */
151                                           /* r15d = dist */
152 "        cld\n"
153 "        cmpq    %%rdi, %%r10\n"
154 "        je      .L_one_time\n"           /* if only one decode left */
155 "        cmpq    %%rsi, %%r9\n"
156 "        je      .L_one_time\n"
157 "        jmp     .L_do_loop\n"
158 
159 ".L_one_time:\n"
160 "        movq    %%r12, %%r8\n"           /* r8 = lmask */
161 "        cmpb    $32, %%bl\n"
162 "        ja      .L_get_length_code_one_time\n"
163 
164 "        lodsl\n"                         /* eax = *(uint *)in++ */
165 "        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
166 "        addb    $32, %%bl\n"             /* bits += 32 */
167 "        shlq    %%cl, %%rax\n"
168 "        orq     %%rax, %%rdx\n"          /* hold |= *((uint *)in)++ << bits */
169 "        jmp     .L_get_length_code_one_time\n"
170 
171 ".align 32,0x90\n"
172 ".L_while_test:\n"
173 "        cmpq    %%rdi, %%r10\n"
174 "        jbe     .L_break_loop\n"
175 "        cmpq    %%rsi, %%r9\n"
176 "        jbe     .L_break_loop\n"
177 
178 ".L_do_loop:\n"
179 "        movq    %%r12, %%r8\n"           /* r8 = lmask */
180 "        cmpb    $32, %%bl\n"
181 "        ja      .L_get_length_code\n"    /* if (32 < bits) */
182 
183 "        lodsl\n"                         /* eax = *(uint *)in++ */
184 "        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
185 "        addb    $32, %%bl\n"             /* bits += 32 */
186 "        shlq    %%cl, %%rax\n"
187 "        orq     %%rax, %%rdx\n"          /* hold |= *((uint *)in)++ << bits */
188 
189 ".L_get_length_code:\n"
190 "        andq    %%rdx, %%r8\n"            /* r8 &= hold */
191 "        movl    (%%rbp,%%r8,4), %%eax\n"  /* eax = lcode[hold & lmask] */
192 
193 "        movb    %%ah, %%cl\n"            /* cl = this.bits */
194 "        subb    %%ah, %%bl\n"            /* bits -= this.bits */
195 "        shrq    %%cl, %%rdx\n"           /* hold >>= this.bits */
196 
197 "        testb   %%al, %%al\n"
198 "        jnz     .L_test_for_length_base\n" /* if (op != 0) 45.7% */
199 
200 "        movq    %%r12, %%r8\n"            /* r8 = lmask */
201 "        shrl    $16, %%eax\n"            /* output this.val char */
202 "        stosb\n"
203 
204 ".L_get_length_code_one_time:\n"
205 "        andq    %%rdx, %%r8\n"            /* r8 &= hold */
206 "        movl    (%%rbp,%%r8,4), %%eax\n" /* eax = lcode[hold & lmask] */
207 
208 ".L_dolen:\n"
209 "        movb    %%ah, %%cl\n"            /* cl = this.bits */
210 "        subb    %%ah, %%bl\n"            /* bits -= this.bits */
211 "        shrq    %%cl, %%rdx\n"           /* hold >>= this.bits */
212 
213 "        testb   %%al, %%al\n"
214 "        jnz     .L_test_for_length_base\n" /* if (op != 0) 45.7% */
215 
216 "        shrl    $16, %%eax\n"            /* output this.val char */
217 "        stosb\n"
218 "        jmp     .L_while_test\n"
219 
220 ".align 32,0x90\n"
221 ".L_test_for_length_base:\n"
222 "        movl    %%eax, %%r14d\n"         /* len = this */
223 "        shrl    $16, %%r14d\n"           /* len = this.val */
224 "        movb    %%al, %%cl\n"
225 
226 "        testb   $16, %%al\n"
227 "        jz      .L_test_for_second_level_length\n" /* if ((op & 16) == 0) 8% */
228 "        andb    $15, %%cl\n"             /* op &= 15 */
229 "        jz      .L_decode_distance\n"    /* if (!op) */
230 
231 ".L_add_bits_to_len:\n"
232 "        subb    %%cl, %%bl\n"
233 "        xorl    %%eax, %%eax\n"
234 "        incl    %%eax\n"
235 "        shll    %%cl, %%eax\n"
236 "        decl    %%eax\n"
237 "        andl    %%edx, %%eax\n"          /* eax &= hold */
238 "        shrq    %%cl, %%rdx\n"
239 "        addl    %%eax, %%r14d\n"         /* len += hold & mask[op] */
240 
241 ".L_decode_distance:\n"
242 "        movq    %%r13, %%r8\n"           /* r8 = dmask */
243 "        cmpb    $32, %%bl\n"
244 "        ja      .L_get_distance_code\n"  /* if (32 < bits) */
245 
246 "        lodsl\n"                         /* eax = *(uint *)in++ */
247 "        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
248 "        addb    $32, %%bl\n"             /* bits += 32 */
249 "        shlq    %%cl, %%rax\n"
250 "        orq     %%rax, %%rdx\n"          /* hold |= *((uint *)in)++ << bits */
251 
252 ".L_get_distance_code:\n"
253 "        andq    %%rdx, %%r8\n"           /* r8 &= hold */
254 "        movl    (%%r11,%%r8,4), %%eax\n" /* eax = dcode[hold & dmask] */
255 
256 ".L_dodist:\n"
257 "        movl    %%eax, %%r15d\n"         /* dist = this */
258 "        shrl    $16, %%r15d\n"           /* dist = this.val */
259 "        movb    %%ah, %%cl\n"
260 "        subb    %%ah, %%bl\n"            /* bits -= this.bits */
261 "        shrq    %%cl, %%rdx\n"           /* hold >>= this.bits */
262 "        movb    %%al, %%cl\n"            /* cl = this.op */
263 
264 "        testb   $16, %%al\n"             /* if ((op & 16) == 0) */
265 "        jz      .L_test_for_second_level_dist\n"
266 "        andb    $15, %%cl\n"             /* op &= 15 */
267 "        jz      .L_check_dist_one\n"
268 
269 ".L_add_bits_to_dist:\n"
270 "        subb    %%cl, %%bl\n"
271 "        xorl    %%eax, %%eax\n"
272 "        incl    %%eax\n"
273 "        shll    %%cl, %%eax\n"
274 "        decl    %%eax\n"                 /* (1 << op) - 1 */
275 "        andl    %%edx, %%eax\n"          /* eax &= hold */
276 "        shrq    %%cl, %%rdx\n"
277 "        addl    %%eax, %%r15d\n"         /* dist += hold & ((1 << op) - 1) */
278 
279 ".L_check_window:\n"
280 "        movq    %%rsi, %%r8\n"           /* save in so from can use it's reg */
281 "        movq    %%rdi, %%rax\n"
282 "        subq    40(%%rsp), %%rax\n"      /* nbytes = out - beg */
283 
284 "        cmpl    %%r15d, %%eax\n"
285 "        jb      .L_clip_window\n"        /* if (dist > nbytes) 4.2% */
286 
287 "        movl    %%r14d, %%ecx\n"         /* ecx = len */
288 "        movq    %%rdi, %%rsi\n"
289 "        subq    %%r15, %%rsi\n"          /* from = out - dist */
290 
291 "        sarl    %%ecx\n"
292 "        jnc     .L_copy_two\n"           /* if len % 2 == 0 */
293 
294 "        rep     movsw\n"
295 "        movb    (%%rsi), %%al\n"
296 "        movb    %%al, (%%rdi)\n"
297 "        incq    %%rdi\n"
298 
299 "        movq    %%r8, %%rsi\n"           /* move in back to %rsi, toss from */
300 "        jmp     .L_while_test\n"
301 
302 ".L_copy_two:\n"
303 "        rep     movsw\n"
304 "        movq    %%r8, %%rsi\n"           /* move in back to %rsi, toss from */
305 "        jmp     .L_while_test\n"
306 
307 ".align 32,0x90\n"
308 ".L_check_dist_one:\n"
309 "        cmpl    $1, %%r15d\n"            /* if dist 1, is a memset */
310 "        jne     .L_check_window\n"
311 "        cmpq    %%rdi, 40(%%rsp)\n"      /* if out == beg, outside window */
312 "        je      .L_check_window\n"
313 
314 "        movl    %%r14d, %%ecx\n"         /* ecx = len */
315 "        movb    -1(%%rdi), %%al\n"
316 "        movb    %%al, %%ah\n"
317 
318 "        sarl    %%ecx\n"
319 "        jnc     .L_set_two\n"
320 "        movb    %%al, (%%rdi)\n"
321 "        incq    %%rdi\n"
322 
323 ".L_set_two:\n"
324 "        rep     stosw\n"
325 "        jmp     .L_while_test\n"
326 
327 ".align 32,0x90\n"
328 ".L_test_for_second_level_length:\n"
329 "        testb   $64, %%al\n"
330 "        jnz     .L_test_for_end_of_block\n" /* if ((op & 64) != 0) */
331 
332 "        xorl    %%eax, %%eax\n"
333 "        incl    %%eax\n"
334 "        shll    %%cl, %%eax\n"
335 "        decl    %%eax\n"
336 "        andl    %%edx, %%eax\n"         /* eax &= hold */
337 "        addl    %%r14d, %%eax\n"        /* eax += len */
338 "        movl    (%%rbp,%%rax,4), %%eax\n" /* eax = lcode[val+(hold&mask[op])]*/
339 "        jmp     .L_dolen\n"
340 
341 ".align 32,0x90\n"
342 ".L_test_for_second_level_dist:\n"
343 "        testb   $64, %%al\n"
344 "        jnz     .L_invalid_distance_code\n" /* if ((op & 64) != 0) */
345 
346 "        xorl    %%eax, %%eax\n"
347 "        incl    %%eax\n"
348 "        shll    %%cl, %%eax\n"
349 "        decl    %%eax\n"
350 "        andl    %%edx, %%eax\n"         /* eax &= hold */
351 "        addl    %%r15d, %%eax\n"        /* eax += dist */
352 "        movl    (%%r11,%%rax,4), %%eax\n" /* eax = dcode[val+(hold&mask[op])]*/
353 "        jmp     .L_dodist\n"
354 
355 ".align 32,0x90\n"
356 ".L_clip_window:\n"
357 "        movl    %%eax, %%ecx\n"         /* ecx = nbytes */
358 "        movl    92(%%rsp), %%eax\n"     /* eax = wsize, prepare for dist cmp */
359 "        negl    %%ecx\n"                /* nbytes = -nbytes */
360 
361 "        cmpl    %%r15d, %%eax\n"
362 "        jb      .L_invalid_distance_too_far\n" /* if (dist > wsize) */
363 
364 "        addl    %%r15d, %%ecx\n"         /* nbytes = dist - nbytes */
365 "        cmpl    $0, 96(%%rsp)\n"
366 "        jne     .L_wrap_around_window\n" /* if (write != 0) */
367 
368 "        movq    56(%%rsp), %%rsi\n"     /* from  = window */
369 "        subl    %%ecx, %%eax\n"         /* eax  -= nbytes */
370 "        addq    %%rax, %%rsi\n"         /* from += wsize - nbytes */
371 
372 "        movl    %%r14d, %%eax\n"        /* eax = len */
373 "        cmpl    %%ecx, %%r14d\n"
374 "        jbe     .L_do_copy\n"           /* if (nbytes >= len) */
375 
376 "        subl    %%ecx, %%eax\n"         /* eax -= nbytes */
377 "        rep     movsb\n"
378 "        movq    %%rdi, %%rsi\n"
379 "        subq    %%r15, %%rsi\n"         /* from = &out[ -dist ] */
380 "        jmp     .L_do_copy\n"
381 
382 ".align 32,0x90\n"
383 ".L_wrap_around_window:\n"
384 "        movl    96(%%rsp), %%eax\n"     /* eax = write */
385 "        cmpl    %%eax, %%ecx\n"
386 "        jbe     .L_contiguous_in_window\n" /* if (write >= nbytes) */
387 
388 "        movl    92(%%rsp), %%esi\n"     /* from  = wsize */
389 "        addq    56(%%rsp), %%rsi\n"     /* from += window */
390 "        addq    %%rax, %%rsi\n"         /* from += write */
391 "        subq    %%rcx, %%rsi\n"         /* from -= nbytes */
392 "        subl    %%eax, %%ecx\n"         /* nbytes -= write */
393 
394 "        movl    %%r14d, %%eax\n"        /* eax = len */
395 "        cmpl    %%ecx, %%eax\n"
396 "        jbe     .L_do_copy\n"           /* if (nbytes >= len) */
397 
398 "        subl    %%ecx, %%eax\n"         /* len -= nbytes */
399 "        rep     movsb\n"
400 "        movq    56(%%rsp), %%rsi\n"     /* from = window */
401 "        movl    96(%%rsp), %%ecx\n"     /* nbytes = write */
402 "        cmpl    %%ecx, %%eax\n"
403 "        jbe     .L_do_copy\n"           /* if (nbytes >= len) */
404 
405 "        subl    %%ecx, %%eax\n"         /* len -= nbytes */
406 "        rep     movsb\n"
407 "        movq    %%rdi, %%rsi\n"
408 "        subq    %%r15, %%rsi\n"         /* from = out - dist */
409 "        jmp     .L_do_copy\n"
410 
411 ".align 32,0x90\n"
412 ".L_contiguous_in_window:\n"
413 "        movq    56(%%rsp), %%rsi\n"     /* rsi = window */
414 "        addq    %%rax, %%rsi\n"
415 "        subq    %%rcx, %%rsi\n"         /* from += write - nbytes */
416 
417 "        movl    %%r14d, %%eax\n"        /* eax = len */
418 "        cmpl    %%ecx, %%eax\n"
419 "        jbe     .L_do_copy\n"           /* if (nbytes >= len) */
420 
421 "        subl    %%ecx, %%eax\n"         /* len -= nbytes */
422 "        rep     movsb\n"
423 "        movq    %%rdi, %%rsi\n"
424 "        subq    %%r15, %%rsi\n"         /* from = out - dist */
425 "        jmp     .L_do_copy\n"           /* if (nbytes >= len) */
426 
427 ".align 32,0x90\n"
428 ".L_do_copy:\n"
429 "        movl    %%eax, %%ecx\n"         /* ecx = len */
430 "        rep     movsb\n"
431 
432 "        movq    %%r8, %%rsi\n"          /* move in back to %esi, toss from */
433 "        jmp     .L_while_test\n"
434 
435 ".L_test_for_end_of_block:\n"
436 "        testb   $32, %%al\n"
437 "        jz      .L_invalid_literal_length_code\n"
438 "        movl    $1, 116(%%rsp)\n"
439 "        jmp     .L_break_loop_with_status\n"
440 
441 ".L_invalid_literal_length_code:\n"
442 "        movl    $2, 116(%%rsp)\n"
443 "        jmp     .L_break_loop_with_status\n"
444 
445 ".L_invalid_distance_code:\n"
446 "        movl    $3, 116(%%rsp)\n"
447 "        jmp     .L_break_loop_with_status\n"
448 
449 ".L_invalid_distance_too_far:\n"
450 "        movl    $4, 116(%%rsp)\n"
451 "        jmp     .L_break_loop_with_status\n"
452 
453 ".L_break_loop:\n"
454 "        movl    $0, 116(%%rsp)\n"
455 
456 ".L_break_loop_with_status:\n"
457 /* put in, out, bits, and hold back into ar and pop esp */
458 "        movq    %%rsi, 16(%%rsp)\n"     /* in */
459 "        movq    %%rdi, 32(%%rsp)\n"     /* out */
460 "        movl    %%ebx, 88(%%rsp)\n"     /* bits */
461 "        movq    %%rdx, 80(%%rsp)\n"     /* hold */
462 "        movq    (%%rsp), %%rax\n"       /* restore rbp and rsp */
463 "        movq    8(%%rsp), %%rbp\n"
464 "        movq    %%rax, %%rsp\n"
465           :
466           : "m" (ar)
467           : "memory", "%rax", "%rbx", "%rcx", "%rdx", "%rsi", "%rdi",
468             "%r8", "%r9", "%r10", "%r11", "%r12", "%r13", "%r14", "%r15"
469     );
470 #elif ( defined( __GNUC__ ) || defined( __ICC ) ) && defined( __i386 )
471     __asm__ __volatile__ (
472 "        leal    %0, %%eax\n"
473 "        movl    %%esp, (%%eax)\n"        /* save esp, ebp */
474 "        movl    %%ebp, 4(%%eax)\n"
475 "        movl    %%eax, %%esp\n"
476 "        movl    8(%%esp), %%esi\n"       /* esi = in */
477 "        movl    16(%%esp), %%edi\n"      /* edi = out */
478 "        movl    40(%%esp), %%edx\n"      /* edx = hold */
479 "        movl    44(%%esp), %%ebx\n"      /* ebx = bits */
480 "        movl    32(%%esp), %%ebp\n"      /* ebp = lcode */
481 
482 "        cld\n"
483 "        jmp     .L_do_loop\n"
484 
485 ".align 32,0x90\n"
486 ".L_while_test:\n"
487 "        cmpl    %%edi, 24(%%esp)\n"      /* out < end */
488 "        jbe     .L_break_loop\n"
489 "        cmpl    %%esi, 12(%%esp)\n"      /* in < last */
490 "        jbe     .L_break_loop\n"
491 
492 ".L_do_loop:\n"
493 "        cmpb    $15, %%bl\n"
494 "        ja      .L_get_length_code\n"    /* if (15 < bits) */
495 
496 "        xorl    %%eax, %%eax\n"
497 "        lodsw\n"                         /* al = *(ushort *)in++ */
498 "        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
499 "        addb    $16, %%bl\n"             /* bits += 16 */
500 "        shll    %%cl, %%eax\n"
501 "        orl     %%eax, %%edx\n"        /* hold |= *((ushort *)in)++ << bits */
502 
503 ".L_get_length_code:\n"
504 "        movl    56(%%esp), %%eax\n"      /* eax = lmask */
505 "        andl    %%edx, %%eax\n"          /* eax &= hold */
506 "        movl    (%%ebp,%%eax,4), %%eax\n" /* eax = lcode[hold & lmask] */
507 
508 ".L_dolen:\n"
509 "        movb    %%ah, %%cl\n"            /* cl = this.bits */
510 "        subb    %%ah, %%bl\n"            /* bits -= this.bits */
511 "        shrl    %%cl, %%edx\n"           /* hold >>= this.bits */
512 
513 "        testb   %%al, %%al\n"
514 "        jnz     .L_test_for_length_base\n" /* if (op != 0) 45.7% */
515 
516 "        shrl    $16, %%eax\n"            /* output this.val char */
517 "        stosb\n"
518 "        jmp     .L_while_test\n"
519 
520 ".align 32,0x90\n"
521 ".L_test_for_length_base:\n"
522 "        movl    %%eax, %%ecx\n"          /* len = this */
523 "        shrl    $16, %%ecx\n"            /* len = this.val */
524 "        movl    %%ecx, 64(%%esp)\n"      /* save len */
525 "        movb    %%al, %%cl\n"
526 
527 "        testb   $16, %%al\n"
528 "        jz      .L_test_for_second_level_length\n" /* if ((op & 16) == 0) 8% */
529 "        andb    $15, %%cl\n"             /* op &= 15 */
530 "        jz      .L_decode_distance\n"    /* if (!op) */
531 "        cmpb    %%cl, %%bl\n"
532 "        jae     .L_add_bits_to_len\n"    /* if (op <= bits) */
533 
534 "        movb    %%cl, %%ch\n"            /* stash op in ch, freeing cl */
535 "        xorl    %%eax, %%eax\n"
536 "        lodsw\n"                         /* al = *(ushort *)in++ */
537 "        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
538 "        addb    $16, %%bl\n"             /* bits += 16 */
539 "        shll    %%cl, %%eax\n"
540 "        orl     %%eax, %%edx\n"         /* hold |= *((ushort *)in)++ << bits */
541 "        movb    %%ch, %%cl\n"            /* move op back to ecx */
542 
543 ".L_add_bits_to_len:\n"
544 "        subb    %%cl, %%bl\n"
545 "        xorl    %%eax, %%eax\n"
546 "        incl    %%eax\n"
547 "        shll    %%cl, %%eax\n"
548 "        decl    %%eax\n"
549 "        andl    %%edx, %%eax\n"          /* eax &= hold */
550 "        shrl    %%cl, %%edx\n"
551 "        addl    %%eax, 64(%%esp)\n"      /* len += hold & mask[op] */
552 
553 ".L_decode_distance:\n"
554 "        cmpb    $15, %%bl\n"
555 "        ja      .L_get_distance_code\n"  /* if (15 < bits) */
556 
557 "        xorl    %%eax, %%eax\n"
558 "        lodsw\n"                         /* al = *(ushort *)in++ */
559 "        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
560 "        addb    $16, %%bl\n"             /* bits += 16 */
561 "        shll    %%cl, %%eax\n"
562 "        orl     %%eax, %%edx\n"         /* hold |= *((ushort *)in)++ << bits */
563 
564 ".L_get_distance_code:\n"
565 "        movl    60(%%esp), %%eax\n"      /* eax = dmask */
566 "        movl    36(%%esp), %%ecx\n"      /* ecx = dcode */
567 "        andl    %%edx, %%eax\n"          /* eax &= hold */
568 "        movl    (%%ecx,%%eax,4), %%eax\n"/* eax = dcode[hold & dmask] */
569 
570 ".L_dodist:\n"
571 "        movl    %%eax, %%ebp\n"          /* dist = this */
572 "        shrl    $16, %%ebp\n"            /* dist = this.val */
573 "        movb    %%ah, %%cl\n"
574 "        subb    %%ah, %%bl\n"            /* bits -= this.bits */
575 "        shrl    %%cl, %%edx\n"           /* hold >>= this.bits */
576 "        movb    %%al, %%cl\n"            /* cl = this.op */
577 
578 "        testb   $16, %%al\n"             /* if ((op & 16) == 0) */
579 "        jz      .L_test_for_second_level_dist\n"
580 "        andb    $15, %%cl\n"             /* op &= 15 */
581 "        jz      .L_check_dist_one\n"
582 "        cmpb    %%cl, %%bl\n"
583 "        jae     .L_add_bits_to_dist\n"   /* if (op <= bits) 97.6% */
584 
585 "        movb    %%cl, %%ch\n"            /* stash op in ch, freeing cl */
586 "        xorl    %%eax, %%eax\n"
587 "        lodsw\n"                         /* al = *(ushort *)in++ */
588 "        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
589 "        addb    $16, %%bl\n"             /* bits += 16 */
590 "        shll    %%cl, %%eax\n"
591 "        orl     %%eax, %%edx\n"        /* hold |= *((ushort *)in)++ << bits */
592 "        movb    %%ch, %%cl\n"            /* move op back to ecx */
593 
594 ".L_add_bits_to_dist:\n"
595 "        subb    %%cl, %%bl\n"
596 "        xorl    %%eax, %%eax\n"
597 "        incl    %%eax\n"
598 "        shll    %%cl, %%eax\n"
599 "        decl    %%eax\n"                 /* (1 << op) - 1 */
600 "        andl    %%edx, %%eax\n"          /* eax &= hold */
601 "        shrl    %%cl, %%edx\n"
602 "        addl    %%eax, %%ebp\n"          /* dist += hold & ((1 << op) - 1) */
603 
604 ".L_check_window:\n"
605 "        movl    %%esi, 8(%%esp)\n"       /* save in so from can use it's reg */
606 "        movl    %%edi, %%eax\n"
607 "        subl    20(%%esp), %%eax\n"      /* nbytes = out - beg */
608 
609 "        cmpl    %%ebp, %%eax\n"
610 "        jb      .L_clip_window\n"        /* if (dist > nbytes) 4.2% */
611 
612 "        movl    64(%%esp), %%ecx\n"      /* ecx = len */
613 "        movl    %%edi, %%esi\n"
614 "        subl    %%ebp, %%esi\n"          /* from = out - dist */
615 
616 "        sarl    %%ecx\n"
617 "        jnc     .L_copy_two\n"           /* if len % 2 == 0 */
618 
619 "        rep     movsw\n"
620 "        movb    (%%esi), %%al\n"
621 "        movb    %%al, (%%edi)\n"
622 "        incl    %%edi\n"
623 
624 "        movl    8(%%esp), %%esi\n"       /* move in back to %esi, toss from */
625 "        movl    32(%%esp), %%ebp\n"      /* ebp = lcode */
626 "        jmp     .L_while_test\n"
627 
628 ".L_copy_two:\n"
629 "        rep     movsw\n"
630 "        movl    8(%%esp), %%esi\n"       /* move in back to %esi, toss from */
631 "        movl    32(%%esp), %%ebp\n"      /* ebp = lcode */
632 "        jmp     .L_while_test\n"
633 
634 ".align 32,0x90\n"
635 ".L_check_dist_one:\n"
636 "        cmpl    $1, %%ebp\n"            /* if dist 1, is a memset */
637 "        jne     .L_check_window\n"
638 "        cmpl    %%edi, 20(%%esp)\n"
639 "        je      .L_check_window\n"      /* out == beg, if outside window */
640 
641 "        movl    64(%%esp), %%ecx\n"      /* ecx = len */
642 "        movb    -1(%%edi), %%al\n"
643 "        movb    %%al, %%ah\n"
644 
645 "        sarl    %%ecx\n"
646 "        jnc     .L_set_two\n"
647 "        movb    %%al, (%%edi)\n"
648 "        incl    %%edi\n"
649 
650 ".L_set_two:\n"
651 "        rep     stosw\n"
652 "        movl    32(%%esp), %%ebp\n"      /* ebp = lcode */
653 "        jmp     .L_while_test\n"
654 
655 ".align 32,0x90\n"
656 ".L_test_for_second_level_length:\n"
657 "        testb   $64, %%al\n"
658 "        jnz     .L_test_for_end_of_block\n" /* if ((op & 64) != 0) */
659 
660 "        xorl    %%eax, %%eax\n"
661 "        incl    %%eax\n"
662 "        shll    %%cl, %%eax\n"
663 "        decl    %%eax\n"
664 "        andl    %%edx, %%eax\n"         /* eax &= hold */
665 "        addl    64(%%esp), %%eax\n"     /* eax += len */
666 "        movl    (%%ebp,%%eax,4), %%eax\n" /* eax = lcode[val+(hold&mask[op])]*/
667 "        jmp     .L_dolen\n"
668 
669 ".align 32,0x90\n"
670 ".L_test_for_second_level_dist:\n"
671 "        testb   $64, %%al\n"
672 "        jnz     .L_invalid_distance_code\n" /* if ((op & 64) != 0) */
673 
674 "        xorl    %%eax, %%eax\n"
675 "        incl    %%eax\n"
676 "        shll    %%cl, %%eax\n"
677 "        decl    %%eax\n"
678 "        andl    %%edx, %%eax\n"         /* eax &= hold */
679 "        addl    %%ebp, %%eax\n"         /* eax += dist */
680 "        movl    36(%%esp), %%ecx\n"     /* ecx = dcode */
681 "        movl    (%%ecx,%%eax,4), %%eax\n" /* eax = dcode[val+(hold&mask[op])]*/
682 "        jmp     .L_dodist\n"
683 
684 ".align 32,0x90\n"
685 ".L_clip_window:\n"
686 "        movl    %%eax, %%ecx\n"
687 "        movl    48(%%esp), %%eax\n"     /* eax = wsize */
688 "        negl    %%ecx\n"                /* nbytes = -nbytes */
689 "        movl    28(%%esp), %%esi\n"     /* from = window */
690 
691 "        cmpl    %%ebp, %%eax\n"
692 "        jb      .L_invalid_distance_too_far\n" /* if (dist > wsize) */
693 
694 "        addl    %%ebp, %%ecx\n"         /* nbytes = dist - nbytes */
695 "        cmpl    $0, 52(%%esp)\n"
696 "        jne     .L_wrap_around_window\n" /* if (write != 0) */
697 
698 "        subl    %%ecx, %%eax\n"
699 "        addl    %%eax, %%esi\n"         /* from += wsize - nbytes */
700 
701 "        movl    64(%%esp), %%eax\n"     /* eax = len */
702 "        cmpl    %%ecx, %%eax\n"
703 "        jbe     .L_do_copy\n"           /* if (nbytes >= len) */
704 
705 "        subl    %%ecx, %%eax\n"         /* len -= nbytes */
706 "        rep     movsb\n"
707 "        movl    %%edi, %%esi\n"
708 "        subl    %%ebp, %%esi\n"         /* from = out - dist */
709 "        jmp     .L_do_copy\n"
710 
711 ".align 32,0x90\n"
712 ".L_wrap_around_window:\n"
713 "        movl    52(%%esp), %%eax\n"     /* eax = write */
714 "        cmpl    %%eax, %%ecx\n"
715 "        jbe     .L_contiguous_in_window\n" /* if (write >= nbytes) */
716 
717 "        addl    48(%%esp), %%esi\n"     /* from += wsize */
718 "        addl    %%eax, %%esi\n"         /* from += write */
719 "        subl    %%ecx, %%esi\n"         /* from -= nbytes */
720 "        subl    %%eax, %%ecx\n"         /* nbytes -= write */
721 
722 "        movl    64(%%esp), %%eax\n"     /* eax = len */
723 "        cmpl    %%ecx, %%eax\n"
724 "        jbe     .L_do_copy\n"           /* if (nbytes >= len) */
725 
726 "        subl    %%ecx, %%eax\n"         /* len -= nbytes */
727 "        rep     movsb\n"
728 "        movl    28(%%esp), %%esi\n"     /* from = window */
729 "        movl    52(%%esp), %%ecx\n"     /* nbytes = write */
730 "        cmpl    %%ecx, %%eax\n"
731 "        jbe     .L_do_copy\n"           /* if (nbytes >= len) */
732 
733 "        subl    %%ecx, %%eax\n"         /* len -= nbytes */
734 "        rep     movsb\n"
735 "        movl    %%edi, %%esi\n"
736 "        subl    %%ebp, %%esi\n"         /* from = out - dist */
737 "        jmp     .L_do_copy\n"
738 
739 ".align 32,0x90\n"
740 ".L_contiguous_in_window:\n"
741 "        addl    %%eax, %%esi\n"
742 "        subl    %%ecx, %%esi\n"         /* from += write - nbytes */
743 
744 "        movl    64(%%esp), %%eax\n"     /* eax = len */
745 "        cmpl    %%ecx, %%eax\n"
746 "        jbe     .L_do_copy\n"           /* if (nbytes >= len) */
747 
748 "        subl    %%ecx, %%eax\n"         /* len -= nbytes */
749 "        rep     movsb\n"
750 "        movl    %%edi, %%esi\n"
751 "        subl    %%ebp, %%esi\n"         /* from = out - dist */
752 "        jmp     .L_do_copy\n"           /* if (nbytes >= len) */
753 
754 ".align 32,0x90\n"
755 ".L_do_copy:\n"
756 "        movl    %%eax, %%ecx\n"
757 "        rep     movsb\n"
758 
759 "        movl    8(%%esp), %%esi\n"      /* move in back to %esi, toss from */
760 "        movl    32(%%esp), %%ebp\n"     /* ebp = lcode */
761 "        jmp     .L_while_test\n"
762 
763 ".L_test_for_end_of_block:\n"
764 "        testb   $32, %%al\n"
765 "        jz      .L_invalid_literal_length_code\n"
766 "        movl    $1, 72(%%esp)\n"
767 "        jmp     .L_break_loop_with_status\n"
768 
769 ".L_invalid_literal_length_code:\n"
770 "        movl    $2, 72(%%esp)\n"
771 "        jmp     .L_break_loop_with_status\n"
772 
773 ".L_invalid_distance_code:\n"
774 "        movl    $3, 72(%%esp)\n"
775 "        jmp     .L_break_loop_with_status\n"
776 
777 ".L_invalid_distance_too_far:\n"
778 "        movl    8(%%esp), %%esi\n"
779 "        movl    $4, 72(%%esp)\n"
780 "        jmp     .L_break_loop_with_status\n"
781 
782 ".L_break_loop:\n"
783 "        movl    $0, 72(%%esp)\n"
784 
785 ".L_break_loop_with_status:\n"
786 /* put in, out, bits, and hold back into ar and pop esp */
787 "        movl    %%esi, 8(%%esp)\n"      /* save in */
788 "        movl    %%edi, 16(%%esp)\n"     /* save out */
789 "        movl    %%ebx, 44(%%esp)\n"     /* save bits */
790 "        movl    %%edx, 40(%%esp)\n"     /* save hold */
791 "        movl    4(%%esp), %%ebp\n"      /* restore esp, ebp */
792 "        movl    (%%esp), %%esp\n"
793           :
794           : "m" (ar)
795           : "memory", "%eax", "%ebx", "%ecx", "%edx", "%esi", "%edi"
796     );
797 #elif defined( _MSC_VER ) && ! defined( _M_AMD64 )
798     __asm {
799 	lea	eax, ar
800 	mov	[eax], esp         /* save esp, ebp */
801 	mov	[eax+4], ebp
802 	mov	esp, eax
803 	mov	esi, [esp+8]       /* esi = in */
804 	mov	edi, [esp+16]      /* edi = out */
805 	mov	edx, [esp+40]      /* edx = hold */
806 	mov	ebx, [esp+44]      /* ebx = bits */
807 	mov	ebp, [esp+32]      /* ebp = lcode */
808 
809 	cld
810 	jmp	L_do_loop
811 
812 ALIGN 4
813 L_while_test:
814 	cmp	[esp+24], edi
815 	jbe	L_break_loop
816 	cmp	[esp+12], esi
817 	jbe	L_break_loop
818 
819 L_do_loop:
820 	cmp	bl, 15
821 	ja	L_get_length_code    /* if (15 < bits) */
822 
823 	xor	eax, eax
824 	lodsw                         /* al = *(ushort *)in++ */
825 	mov	cl, bl            /* cl = bits, needs it for shifting */
826 	add	bl, 16             /* bits += 16 */
827 	shl	eax, cl
828 	or	edx, eax        /* hold |= *((ushort *)in)++ << bits */
829 
830 L_get_length_code:
831 	mov	eax, [esp+56]      /* eax = lmask */
832 	and	eax, edx          /* eax &= hold */
833 	mov	eax, [ebp+eax*4] /* eax = lcode[hold & lmask] */
834 
835 L_dolen:
836 	mov	cl, ah            /* cl = this.bits */
837 	sub	bl, ah            /* bits -= this.bits */
838 	shr	edx, cl           /* hold >>= this.bits */
839 
840 	test	al, al
841 	jnz	L_test_for_length_base /* if (op != 0) 45.7% */
842 
843 	shr	eax, 16            /* output this.val char */
844 	stosb
845 	jmp	L_while_test
846 
847 ALIGN 4
848 L_test_for_length_base:
849 	mov	ecx, eax          /* len = this */
850 	shr	ecx, 16            /* len = this.val */
851 	mov	[esp+64], ecx      /* save len */
852 	mov	cl, al
853 
854 	test	al, 16
855 	jz	L_test_for_second_level_length /* if ((op & 16) == 0) 8% */
856 	and	cl, 15             /* op &= 15 */
857 	jz	L_decode_distance    /* if (!op) */
858 	cmp	bl, cl
859 	jae	L_add_bits_to_len    /* if (op <= bits) */
860 
861 	mov	ch, cl            /* stash op in ch, freeing cl */
862 	xor	eax, eax
863 	lodsw                         /* al = *(ushort *)in++ */
864 	mov	cl, bl            /* cl = bits, needs it for shifting */
865 	add	bl, 16             /* bits += 16 */
866 	shl	eax, cl
867 	or	edx, eax         /* hold |= *((ushort *)in)++ << bits */
868 	mov	cl, ch            /* move op back to ecx */
869 
870 L_add_bits_to_len:
871 	sub	bl, cl
872 	xor	eax, eax
873 	inc	eax
874 	shl	eax, cl
875 	dec	eax
876 	and	eax, edx          /* eax &= hold */
877 	shr	edx, cl
878 	add	[esp+64], eax      /* len += hold & mask[op] */
879 
880 L_decode_distance:
881 	cmp	bl, 15
882 	ja	L_get_distance_code  /* if (15 < bits) */
883 
884 	xor	eax, eax
885 	lodsw                         /* al = *(ushort *)in++ */
886 	mov	cl, bl            /* cl = bits, needs it for shifting */
887 	add	bl, 16             /* bits += 16 */
888 	shl	eax, cl
889 	or	edx, eax         /* hold |= *((ushort *)in)++ << bits */
890 
891 L_get_distance_code:
892 	mov	eax, [esp+60]      /* eax = dmask */
893 	mov	ecx, [esp+36]      /* ecx = dcode */
894 	and	eax, edx          /* eax &= hold */
895 	mov	eax, [ecx+eax*4]/* eax = dcode[hold & dmask] */
896 
897 L_dodist:
898 	mov	ebp, eax          /* dist = this */
899 	shr	ebp, 16            /* dist = this.val */
900 	mov	cl, ah
901 	sub	bl, ah            /* bits -= this.bits */
902 	shr	edx, cl           /* hold >>= this.bits */
903 	mov	cl, al            /* cl = this.op */
904 
905 	test	al, 16             /* if ((op & 16) == 0) */
906 	jz	L_test_for_second_level_dist
907 	and	cl, 15             /* op &= 15 */
908 	jz	L_check_dist_one
909 	cmp	bl, cl
910 	jae	L_add_bits_to_dist   /* if (op <= bits) 97.6% */
911 
912 	mov	ch, cl            /* stash op in ch, freeing cl */
913 	xor	eax, eax
914 	lodsw                         /* al = *(ushort *)in++ */
915 	mov	cl, bl            /* cl = bits, needs it for shifting */
916 	add	bl, 16             /* bits += 16 */
917 	shl	eax, cl
918 	or	edx, eax        /* hold |= *((ushort *)in)++ << bits */
919 	mov	cl, ch            /* move op back to ecx */
920 
921 L_add_bits_to_dist:
922 	sub	bl, cl
923 	xor	eax, eax
924 	inc	eax
925 	shl	eax, cl
926 	dec	eax                 /* (1 << op) - 1 */
927 	and	eax, edx          /* eax &= hold */
928 	shr	edx, cl
929 	add	ebp, eax          /* dist += hold & ((1 << op) - 1) */
930 
931 L_check_window:
932 	mov	[esp+8], esi       /* save in so from can use it's reg */
933 	mov	eax, edi
934 	sub	eax, [esp+20]      /* nbytes = out - beg */
935 
936 	cmp	eax, ebp
937 	jb	L_clip_window        /* if (dist > nbytes) 4.2% */
938 
939 	mov	ecx, [esp+64]      /* ecx = len */
940 	mov	esi, edi
941 	sub	esi, ebp          /* from = out - dist */
942 
943 	sar	ecx, 1
944 	jnc	L_copy_two
945 
946 	rep     movsw
947 	mov	al, [esi]
948 	mov	[edi], al
949 	inc	edi
950 
951 	mov	esi, [esp+8]      /* move in back to %esi, toss from */
952 	mov	ebp, [esp+32]     /* ebp = lcode */
953 	jmp	L_while_test
954 
955 L_copy_two:
956 	rep     movsw
957 	mov	esi, [esp+8]      /* move in back to %esi, toss from */
958 	mov	ebp, [esp+32]     /* ebp = lcode */
959 	jmp	L_while_test
960 
961 ALIGN 4
962 L_check_dist_one:
963 	cmp	ebp, 1            /* if dist 1, is a memset */
964 	jne	L_check_window
965 	cmp	[esp+20], edi
966 	je	L_check_window    /* out == beg, if outside window */
967 
968 	mov	ecx, [esp+64]     /* ecx = len */
969 	mov	al, [edi-1]
970 	mov	ah, al
971 
972 	sar	ecx, 1
973 	jnc	L_set_two
974 	mov	[edi], al         /* memset out with from[-1] */
975 	inc	edi
976 
977 L_set_two:
978 	rep     stosw
979 	mov	ebp, [esp+32]     /* ebp = lcode */
980 	jmp	L_while_test
981 
982 ALIGN 4
983 L_test_for_second_level_length:
984 	test	al, 64
985 	jnz	L_test_for_end_of_block /* if ((op & 64) != 0) */
986 
987 	xor	eax, eax
988 	inc	eax
989 	shl	eax, cl
990 	dec	eax
991 	and	eax, edx         /* eax &= hold */
992 	add	eax, [esp+64]     /* eax += len */
993 	mov	eax, [ebp+eax*4] /* eax = lcode[val+(hold&mask[op])]*/
994 	jmp	L_dolen
995 
996 ALIGN 4
997 L_test_for_second_level_dist:
998 	test	al, 64
999 	jnz	L_invalid_distance_code /* if ((op & 64) != 0) */
1000 
1001 	xor	eax, eax
1002 	inc	eax
1003 	shl	eax, cl
1004 	dec	eax
1005 	and	eax, edx         /* eax &= hold */
1006 	add	eax, ebp         /* eax += dist */
1007 	mov	ecx, [esp+36]     /* ecx = dcode */
1008 	mov	eax, [ecx+eax*4] /* eax = dcode[val+(hold&mask[op])]*/
1009 	jmp	L_dodist
1010 
1011 ALIGN 4
1012 L_clip_window:
1013 	mov	ecx, eax
1014 	mov	eax, [esp+48]     /* eax = wsize */
1015 	neg	ecx                /* nbytes = -nbytes */
1016 	mov	esi, [esp+28]     /* from = window */
1017 
1018 	cmp	eax, ebp
1019 	jb	L_invalid_distance_too_far /* if (dist > wsize) */
1020 
1021 	add	ecx, ebp         /* nbytes = dist - nbytes */
1022 	cmp	dword ptr [esp+52], 0
1023 	jne	L_wrap_around_window /* if (write != 0) */
1024 
1025 	sub	eax, ecx
1026 	add	esi, eax         /* from += wsize - nbytes */
1027 
1028 	mov	eax, [esp+64]    /* eax = len */
1029 	cmp	eax, ecx
1030 	jbe	L_do_copy          /* if (nbytes >= len) */
1031 
1032 	sub	eax, ecx         /* len -= nbytes */
1033 	rep     movsb
1034 	mov	esi, edi
1035 	sub	esi, ebp         /* from = out - dist */
1036 	jmp	L_do_copy
1037 
1038 ALIGN 4
1039 L_wrap_around_window:
1040 	mov	eax, [esp+52]    /* eax = write */
1041 	cmp	ecx, eax
1042 	jbe	L_contiguous_in_window /* if (write >= nbytes) */
1043 
1044 	add	esi, [esp+48]    /* from += wsize */
1045 	add	esi, eax         /* from += write */
1046 	sub	esi, ecx         /* from -= nbytes */
1047 	sub	ecx, eax         /* nbytes -= write */
1048 
1049 	mov	eax, [esp+64]    /* eax = len */
1050 	cmp	eax, ecx
1051 	jbe	L_do_copy          /* if (nbytes >= len) */
1052 
1053 	sub	eax, ecx         /* len -= nbytes */
1054 	rep     movsb
1055 	mov	esi, [esp+28]     /* from = window */
1056 	mov	ecx, [esp+52]     /* nbytes = write */
1057 	cmp	eax, ecx
1058 	jbe	L_do_copy          /* if (nbytes >= len) */
1059 
1060 	sub	eax, ecx         /* len -= nbytes */
1061 	rep     movsb
1062 	mov	esi, edi
1063 	sub	esi, ebp         /* from = out - dist */
1064 	jmp	L_do_copy
1065 
1066 ALIGN 4
1067 L_contiguous_in_window:
1068 	add	esi, eax
1069 	sub	esi, ecx         /* from += write - nbytes */
1070 
1071 	mov	eax, [esp+64]    /* eax = len */
1072 	cmp	eax, ecx
1073 	jbe	L_do_copy          /* if (nbytes >= len) */
1074 
1075 	sub	eax, ecx         /* len -= nbytes */
1076 	rep     movsb
1077 	mov	esi, edi
1078 	sub	esi, ebp         /* from = out - dist */
1079 	jmp	L_do_copy
1080 
1081 ALIGN 4
1082 L_do_copy:
1083 	mov	ecx, eax
1084 	rep     movsb
1085 
1086 	mov	esi, [esp+8]      /* move in back to %esi, toss from */
1087 	mov	ebp, [esp+32]     /* ebp = lcode */
1088 	jmp	L_while_test
1089 
1090 L_test_for_end_of_block:
1091 	test	al, 32
1092 	jz	L_invalid_literal_length_code
1093 	mov	dword ptr [esp+72], 1
1094 	jmp	L_break_loop_with_status
1095 
1096 L_invalid_literal_length_code:
1097 	mov	dword ptr [esp+72], 2
1098 	jmp	L_break_loop_with_status
1099 
1100 L_invalid_distance_code:
1101 	mov	dword ptr [esp+72], 3
1102 	jmp	L_break_loop_with_status
1103 
1104 L_invalid_distance_too_far:
1105 	mov	esi, [esp+4]
1106 	mov	dword ptr [esp+72], 4
1107 	jmp	L_break_loop_with_status
1108 
1109 L_break_loop:
1110 	mov	dword ptr [esp+72], 0
1111 
1112 L_break_loop_with_status:
1113 /* put in, out, bits, and hold back into ar and pop esp */
1114 	mov	[esp+8], esi     /* save in */
1115 	mov	[esp+16], edi    /* save out */
1116 	mov	[esp+44], ebx    /* save bits */
1117 	mov	[esp+40], edx    /* save hold */
1118 	mov	ebp, [esp+4]     /* restore esp, ebp */
1119 	mov	esp, [esp]
1120     }
1121 #else
1122 #error "x86 architecture not defined"
1123 #endif
1124 
1125     if (ar.status > 1) {
1126         if (ar.status == 2)
1127             strm->msg = "invalid literal/length code";
1128         else if (ar.status == 3)
1129             strm->msg = "invalid distance code";
1130         else
1131             strm->msg = "invalid distance too far back";
1132         state->mode = BAD;
1133     }
1134     else if ( ar.status == 1 ) {
1135         state->mode = TYPE;
1136     }
1137 
1138     /* return unused bytes (on entry, bits < 8, so in won't go too far back) */
1139     ar.len = ar.bits >> 3;
1140     ar.in -= ar.len;
1141     ar.bits -= ar.len << 3;
1142     ar.hold &= (1U << ar.bits) - 1;
1143 
1144     /* update state and return */
1145     strm->next_in = ar.in;
1146     strm->next_out = ar.out;
1147     strm->avail_in = (unsigned)(ar.in < ar.last ?
1148                                 PAD_AVAIL_IN + (ar.last - ar.in) :
1149                                 PAD_AVAIL_IN - (ar.in - ar.last));
1150     strm->avail_out = (unsigned)(ar.out < ar.end ?
1151                                  PAD_AVAIL_OUT + (ar.end - ar.out) :
1152                                  PAD_AVAIL_OUT - (ar.out - ar.end));
1153     state->hold = ar.hold;
1154     state->bits = ar.bits;
1155     return;
1156 }
1157 
1158