1 /* inffas8664.c is a hand tuned assembler version of inffast.c - fast decoding
2 * version for AMD64 on Windows using Microsoft C compiler
3 *
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 * 2005 - Adaptation to Microsoft C Compiler for AMD64 by Gilles Vollant
11 *
12 * inffas8664.c call function inffas8664fnc in inffasx64.asm
13 * inffasx64.asm is automatically convert from AMD64 portion of inffas86.c
14 *
15 * Dec-29-2003 -- I added AMD64 inflate asm support. This version is also
16 * slightly quicker on x86 systems because, instead of using rep movsb to copy
17 * data, it uses rep movsw, which moves data in 2-byte chunks instead of single
18 * bytes. I've tested the AMD64 code on a Fedora Core 1 + the x86_64 updates
19 * from http://fedora.linux.duke.edu/fc1_x86_64
20 * which is running on an Athlon 64 3000+ / Gigabyte GA-K8VT800M system with
21 * 1GB ram. The 64-bit version is about 4% faster than the 32-bit version,
22 * when decompressing mozilla-source-1.3.tar.gz.
23 *
24 * Mar-13-2003 -- Most of this is derived from inffast.S which is derived from
25 * the gcc -S output of zlib-1.2.0/inffast.c. Zlib-1.2.0 is in beta release at
26 * the moment. I have successfully compiled and tested this code with gcc2.96,
27 * gcc3.2, icc5.0, msvc6.0. It is very close to the speed of inffast.S
28 * compiled with gcc -DNO_MMX, but inffast.S is still faster on the P3 with MMX
29 * enabled. I will attempt to merge the MMX code into this version. Newer
30 * versions of this and inffast.S can be found at
31 * http://www.eetbeetee.com/zlib/ and http://www.charm.net/~christop/zlib/
32 *
33 */
34
35 #include <stdio.h>
36 #include "zutil.h"
37 #include "inftrees.h"
38 #include "inflate.h"
39 #include "inffast.h"
40
41 /* Mark Adler's comments from inffast.c: */
42
43 /*
44 Decode literal, length, and distance codes and write out the resulting
45 literal and match bytes until either not enough input or output is
46 available, an end-of-block is encountered, or a data error is encountered.
47 When large enough input and output buffers are supplied to inflate(), for
48 example, a 16K input buffer and a 64K output buffer, more than 95% of the
49 inflate execution time is spent in this routine.
50
51 Entry assumptions:
52
53 state->mode == LEN
54 strm->avail_in >= 6
55 strm->avail_out >= 258
56 start >= strm->avail_out
57 state->bits < 8
58
59 On return, state->mode is one of:
60
61 LEN -- ran out of enough output space or enough available input
62 TYPE -- reached end of block code, inflate() to interpret next block
63 BAD -- error in block data
64
65 Notes:
66
67 - The maximum input bits used by a length/distance pair is 15 bits for the
68 length code, 5 bits for the length extra, 15 bits for the distance code,
69 and 13 bits for the distance extra. This totals 48 bits, or six bytes.
70 Therefore if strm->avail_in >= 6, then there is enough input to avoid
71 checking for available input while decoding.
72
73 - The maximum bytes that a single length/distance pair can output is 258
74 bytes, which is the maximum length that can be coded. inflate_fast()
75 requires strm->avail_out >= 258 for each loop to avoid checking for
76 output space.
77 */
78
79
80
81 typedef struct inffast_ar {
82 /* 64 32 x86 x86_64 */
83 /* ar offset register */
84 /* 0 0 */ void *esp; /* esp save */
85 /* 8 4 */ void *ebp; /* ebp save */
86 /* 16 8 */ unsigned char FAR *in; /* esi rsi local strm->next_in */
87 /* 24 12 */ unsigned char FAR *last; /* r9 while in < last */
88 /* 32 16 */ unsigned char FAR *out; /* edi rdi local strm->next_out */
89 /* 40 20 */ unsigned char FAR *beg; /* inflate()'s init next_out */
90 /* 48 24 */ unsigned char FAR *end; /* r10 while out < end */
91 /* 56 28 */ unsigned char FAR *window;/* size of window, wsize!=0 */
92 /* 64 32 */ code const FAR *lcode; /* ebp rbp local strm->lencode */
93 /* 72 36 */ code const FAR *dcode; /* r11 local strm->distcode */
94 /* 80 40 */ size_t /*unsigned long */hold; /* edx rdx local strm->hold */
95 /* 88 44 */ unsigned bits; /* ebx rbx local strm->bits */
96 /* 92 48 */ unsigned wsize; /* window size */
97 /* 96 52 */ unsigned write; /* window write index */
98 /*100 56 */ unsigned lmask; /* r12 mask for lcode */
99 /*104 60 */ unsigned dmask; /* r13 mask for dcode */
100 /*108 64 */ unsigned len; /* r14 match length */
101 /*112 68 */ unsigned dist; /* r15 match distance */
102 /*116 72 */ unsigned status; /* set when state chng*/
103 } type_ar;
104 #ifdef ASMINF
105
106 void inflate_fast(strm, start)
107 z_streamp strm;
108 unsigned start; /* inflate()'s starting value for strm->avail_out */
109 {
110 struct inflate_state FAR *state;
111 type_ar ar;
112 void inffas8664fnc(struct inffast_ar * par);
113
114
115
116 #if (defined( __GNUC__ ) && defined( __amd64__ ) && ! defined( __i386 )) || (defined(_MSC_VER) && defined(_M_AMD64))
117 #define PAD_AVAIL_IN 6
118 #define PAD_AVAIL_OUT 258
119 #else
120 #define PAD_AVAIL_IN 5
121 #define PAD_AVAIL_OUT 257
122 #endif
123
124 /* copy state to local variables */
125 state = (struct inflate_state FAR *)strm->state;
126
127 ar.in = strm->next_in;
128 ar.last = ar.in + (strm->avail_in - PAD_AVAIL_IN);
129 ar.out = strm->next_out;
130 ar.beg = ar.out - (start - strm->avail_out);
131 ar.end = ar.out + (strm->avail_out - PAD_AVAIL_OUT);
132 ar.wsize = state->wsize;
133 ar.write = state->wnext;
134 ar.window = state->window;
135 ar.hold = state->hold;
136 ar.bits = state->bits;
137 ar.lcode = state->lencode;
138 ar.dcode = state->distcode;
139 ar.lmask = (1U << state->lenbits) - 1;
140 ar.dmask = (1U << state->distbits) - 1;
141
142 /* decode literals and length/distances until end-of-block or not enough
143 input data or output space */
144
145 /* align in on 1/2 hold size boundary */
146 while (((size_t)(void *)ar.in & (sizeof(ar.hold) / 2 - 1)) != 0) {
147 ar.hold += (unsigned long)*ar.in++ << ar.bits;
148 ar.bits += 8;
149 }
150
151 inffas8664fnc(&ar);
152
153 if (ar.status > 1) {
154 if (ar.status == 2)
155 strm->msg = "invalid literal/length code";
156 else if (ar.status == 3)
157 strm->msg = "invalid distance code";
158 else
159 strm->msg = "invalid distance too far back";
160 state->mode = BAD;
161 }
162 else if ( ar.status == 1 ) {
163 state->mode = TYPE;
164 }
165
166 /* return unused bytes (on entry, bits < 8, so in won't go too far back) */
167 ar.len = ar.bits >> 3;
168 ar.in -= ar.len;
169 ar.bits -= ar.len << 3;
170 ar.hold &= (1U << ar.bits) - 1;
171
172 /* update state and return */
173 strm->next_in = ar.in;
174 strm->next_out = ar.out;
175 strm->avail_in = (unsigned)(ar.in < ar.last ?
176 PAD_AVAIL_IN + (ar.last - ar.in) :
177 PAD_AVAIL_IN - (ar.in - ar.last));
178 strm->avail_out = (unsigned)(ar.out < ar.end ?
179 PAD_AVAIL_OUT + (ar.end - ar.out) :
180 PAD_AVAIL_OUT - (ar.out - ar.end));
181 state->hold = (unsigned long)ar.hold;
182 state->bits = ar.bits;
183 return;
184 }
185
186 #endif