inffas86.c

测试过的

/* inffas86.c is a hand tuned assembler version of
 *
 * inffast.c -- fast decoding
 * Copyright (C) 1995-2003 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 *
 * Copyright (C) 2003 Chris Anderson <[e-mail]>
 * Please use the copyright conditions above.
 *
 * Dec-29-2003 -- I added AMD64 inflate asm support.  This version is also
 * slightly quicker on x86 systems because, instead of using rep movsb to copy
 * data, it uses rep movsw, which moves data in 2-byte chunks instead of single
 * bytes.  I've tested the AMD64 code on a Fedora Core 1 + the x86_64 updates
 * from http://fedora.linux.duke.edu/fc1_x86_64
 * which is running on an Athlon 64 3000+ / Gigabyte GA-K8VT800M system with
 * 1GB ram.  The 64-bit version is about 4% faster than the 32-bit version,
 * when decompressing mozilla-source-1.3.tar.gz.
 *
 * Mar-13-2003 -- Most of this is derived from inffast.S which is derived from
 * the gcc -S output of zlib-1.2.0/inffast.c.  Zlib-1.2.0 is in beta release at
 * the moment.  I have successfully compiled and tested this code with gcc2.96,
 * gcc3.2, icc5.0, msvc6.0.  It is very close to the speed of inffast.S
 * compiled with gcc -DNO_MMX, but inffast.S is still faster on the P3 with MMX
 * enabled.  I will attempt to merge the MMX code into this version.  Newer
 * versions of this and inffast.S can be found at
 * http://www.eetbeetee.com/zlib/ and http://www.charm.net/~christop/zlib/
 */

#include "zutil.h"
#include "inftrees.h"
#include "inflate.h"
#include "inffast.h"

/* Mark Adler's comments from inffast.c: */

/*
   Decode literal, length, and distance codes and write out the resulting
   literal and match bytes until either not enough input or output is
   available, an end-of-block is encountered, or a data error is encountered.
   When large enough input and output buffers are supplied to inflate(), for
   example, a 16K input buffer and a 64K output buffer, more than 95% of the
   inflate execution time is spent in this routine.

   Entry assumptions:

        state->mode == LEN
        strm->avail_in >= 6
        strm->avail_out >= 258
        start >= strm->avail_out
        state->bits < 8

   On return, state->mode is one of:

        LEN -- ran out of enough output space or enough available input
        TYPE -- reached end of block code, inflate() to interpret next block
        BAD -- error in block data

   Notes:

    - The maximum input bits used by a length/distance pair is 15 bits for the
      length code, 5 bits for the length extra, 15 bits for the distance code,
      and 13 bits for the distance extra.  This totals 48 bits, or six bytes.
      Therefore if strm->avail_in >= 6, then there is enough input to avoid
      checking for available input while decoding.

    - The maximum bytes that a single length/distance pair can output is 258
      bytes, which is the maximum length that can be coded.  inflate_fast()
      requires strm->avail_out >= 258 for each loop to avoid checking for
      output space.
 */
void inflate_fast(strm, start)
z_streamp strm;
unsigned start;         /* inflate()'s starting value for strm->avail_out */
{
    struct inflate_state FAR *state;
    struct inffast_ar {
/* 64   32                               x86  x86_64 */
/* ar offset                              register */
/*  0    0 */ void *esp;                /* esp save */
/*  8    4 */ void *ebp;                /* ebp save */
/* 16    8 */ unsigned char FAR *in;    /* esi rsi  local strm->next_in */
/* 24   12 */ unsigned char FAR *last;  /*     r9   while in < last */
/* 32   16 */ unsigned char FAR *out;   /* edi rdi  local strm->next_out */
/* 40   20 */ unsigned char FAR *beg;   /*          inflate()'s init next_out */
/* 48   24 */ unsigned char FAR *end;   /*     r10  while out < end */
/* 56   28 */ unsigned char FAR *window;/*          size of window, wsize!=0 */
/* 64   32 */ code const FAR *lcode;    /* ebp rbp  local strm->lencode */
/* 72   36 */ code const FAR *dcode;    /*     r11  local strm->distcode */
/* 80   40 */ unsigned long hold;       /* edx rdx  local strm->hold */
/* 88   44 */ unsigned bits;            /* ebx rbx  local strm->bits */
/* 92   48 */ unsigned wsize;           /*          window size */
/* 96   52 */ unsigned write;           /*          window write index */
/*100   56 */ unsigned lmask;           /*     r12  mask for lcode */
/*104   60 */ unsigned dmask;           /*     r13  mask for dcode */
/*108   64 */ unsigned len;             /*     r14  match length */
/*112   68 */ unsigned dist;            /*     r15  match distance */
/*116   72 */ unsigned status;          /*          set when state chng*/
    } ar;

#if defined( __GNUC__ ) && defined( __amd64__ ) && ! defined( __i386 )
#define PAD_AVAIL_IN 6
#define PAD_AVAIL_OUT 258
#else
#define PAD_AVAIL_IN 5
#define PAD_AVAIL_OUT 257
#endif

    /* copy state to local variables */
    state = (struct inflate_state FAR *)strm->state;
    ar.in = strm->next_in;
    ar.last = ar.in + (strm->avail_in - PAD_AVAIL_IN);
    ar.out = strm->next_out;
    ar.beg = ar.out - (start - strm->avail_out);
    ar.end = ar.out + (strm->avail_out - PAD_AVAIL_OUT);
    ar.wsize = state->wsize;
    ar.write = state->write;
    ar.window = state->window;
    ar.hold = state->hold;
    ar.bits = state->bits;
    ar.lcode = state->lencode;
    ar.dcode = state->distcode;
    ar.lmask = (1U << state->lenbits) - 1;
    ar.dmask = (1U << state->distbits) - 1;

    /* decode literals and length/distances until end-of-block or not enough
       input data or output space */

    /* align in on 1/2 hold size boundary */
    while (((unsigned long)(void *)ar.in & (sizeof(ar.hold) / 2 - 1)) != 0) {
        ar.hold += (unsigned long)*ar.in++ << ar.bits;
        ar.bits += 8;
    }

#if defined( __GNUC__ ) && defined( __amd64__ ) && ! defined( __i386 )
    __asm__ __volatile__ (
"        leaq    %0, %%rax\n"
"        movq    %%rbp, 8(%%rax)\n"       /* save regs rbp and rsp */
"        movq    %%rsp, (%%rax)\n"
"        movq    %%rax, %%rsp\n"          /* make rsp point to &ar */
"        movq    16(%%rsp), %%rsi\n"      /* rsi  = in */
"        movq    32(%%rsp), %%rdi\n"      /* rdi  = out */
"        movq    24(%%rsp), %%r9\n"       /* r9   = last */
"        movq    48(%%rsp), %%r10\n"      /* r10  = end */
"        movq    64(%%rsp), %%rbp\n"      /* rbp  = lcode */
"        movq    72(%%rsp), %%r11\n"      /* r11  = dcode */
"        movq    80(%%rsp), %%rdx\n"      /* rdx  = hold */
"        movl    88(%%rsp), %%ebx\n"      /* ebx  = bits */
"        movl    100(%%rsp), %%r12d\n"    /* r12d = lmask */
"        movl    104(%%rsp), %%r13d\n"    /* r13d = dmask */
                                          /* r14d = len */
                                          /* r15d = dist */
"        cld\n"
"        cmpq    %%rdi, %%r10\n"
"        je      .L_one_time\n"           /* if only one decode left */
"        cmpq    %%rsi, %%r9\n"
"        je      .L_one_time\n"
"        jmp     .L_do_loop\n"

".L_one_time:\n"
"        movq    %%r12, %%r8\n"           /* r8 = lmask */
"        cmpb    $32, %%bl\n"
"        ja      .L_get_length_code_one_time\n"

"        lodsl\n"                         /* eax = *(uint *)in++ */
"        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
"        addb    $32, %%bl\n"             /* bits += 32 */
"        shlq    %%cl, %%rax\n"
"        orq     %%rax, %%rdx\n"          /* hold |= *((uint *)in)++ << bits */
"        jmp     .L_get_length_code_one_time\n"

".align 32,0x90\n"
".L_while_test:\n"
"        cmpq    %%rdi, %%r10\n"
"        jbe     .L_break_loop\n"
"        cmpq    %%rsi, %%r9\n"
"        jbe     .L_break_loop\n"

".L_do_loop:\n"
"        movq    %%r12, %%r8\n"           /* r8 = lmask */
"        cmpb    $32, %%bl\n"
"        ja      .L_get_length_code\n"    /* if (32 < bits) */

"        lodsl\n"                         /* eax = *(uint *)in++ */
"        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
"        addb    $32, %%bl\n"             /* bits += 32 */
"        shlq    %%cl, %%rax\n"
"        orq     %%rax, %%rdx\n"          /* hold |= *((uint *)in)++ << bits */

".L_get_length_code:\n"
"        andq    %%rdx, %%r8\n"            /* r8 &= hold */
"        movl    (%%rbp,%%r8,4), %%eax\n"  /* eax = lcode[hold & lmask] */

"        movb    %%ah, %%cl\n"            /* cl = this.bits */
"        subb    %%ah, %%bl\n"            /* bits -= this.bits */
"        shrq    %%cl, %%rdx\n"           /* hold >>= this.bits */

"        testb   %%al, %%al\n"
"        jnz     .L_test_for_length_base\n" /* if (op != 0) 45.7% */

"        movq    %%r12, %%r8\n"            /* r8 = lmask */
"        shrl    $16, %%eax\n"            /* output this.val char */
"        stosb\n"

".L_get_length_code_one_time:\n"
"        andq    %%rdx, %%r8\n"            /* r8 &= hold */
"        movl    (%%rbp,%%r8,4), %%eax\n" /* eax = lcode[hold & lmask] */

".L_dolen:\n"
"        movb    %%ah, %%cl\n"            /* cl = this.bits */
"        subb    %%ah, %%bl\n"            /* bits -= this.bits */
"        shrq    %%cl, %%rdx\n"           /* hold >>= this.bits */

"        testb   %%al, %%al\n"
"        jnz     .L_test_for_length_base\n" /* if (op != 0) 45.7% */

"        shrl    $16, %%eax\n"            /* output this.val char */
"        stosb\n"
"        jmp     .L_while_test\n"

".align 32,0x90\n"
".L_test_for_length_base:\n"
"        movl    %%eax, %%r14d\n"         /* len = this */
"        shrl    $16, %%r14d\n"           /* len = this.val */
"        movb    %%al, %%cl\n"

"        testb   $16, %%al\n"
"        jz      .L_test_for_second_level_length\n" /* if ((op & 16) == 0) 8% */
"        andb    $15, %%cl\n"             /* op &= 15 */
"        jz      .L_decode_distance\n"    /* if (!op) */

".L_add_bits_to_len:\n"
"        subb    %%cl, %%bl\n"
"        xorl    %%eax, %%eax\n"
"        incl    %%eax\n"
"        shll    %%cl, %%eax\n"
"        decl    %%eax\n"
"        andl    %%edx, %%eax\n"          /* eax &= hold */
"        shrq    %%cl, %%rdx\n"
"        addl    %%eax, %%r14d\n"         /* len += hold & mask[op] */

".L_decode_distance:\n"
"        movq    %%r13, %%r8\n"           /* r8 = dmask */
"        cmpb    $32, %%bl\n"
"        ja      .L_get_distance_code\n"  /* if (32 < bits) */

"        lodsl\n"                         /* eax = *(uint *)in++ */
"        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
"        addb    $32, %%bl\n"             /* bits += 32 */
"        shlq    %%cl, %%rax\n"
"        orq     %%rax, %%rdx\n"          /* hold |= *((uint *)in)++ << bits */

".L_get_distance_code:\n"
"        andq    %%rdx, %%r8\n"           /* r8 &= hold */
"        movl    (%%r11,%%r8,4), %%eax\n" /* eax = dcode[hold & dmask] */

".L_dodist:\n"
"        movl    %%eax, %%r15d\n"         /* dist = this */
"        shrl    $16, %%r15d\n"           /* dist = this.val */
"        movb    %%ah, %%cl\n"
"        subb    %%ah, %%bl\n"            /* bits -= this.bits */
"        shrq    %%cl, %%rdx\n"           /* hold >>= this.bits */
"        movb    %%al, %%cl\n"            /* cl = this.op */

"        testb   $16, %%al\n"             /* if ((op & 16) == 0) */
"        jz      .L_test_for_second_level_dist\n"
"        andb    $15, %%cl\n"             /* op &= 15 */
"        jz      .L_check_dist_one\n"

".L_add_bits_to_dist:\n"
"        subb    %%cl, %%bl\n"
"        xorl    %%eax, %%eax\n"
"        incl    %%eax\n"
"        shll    %%cl, %%eax\n"
"        decl    %%eax\n"                 /* (1 << op) - 1 */
"        andl    %%edx, %%eax\n"          /* eax &= hold */
"        shrq    %%cl, %%rdx\n"
"        addl    %%eax, %%r15d\n"         /* dist += hold & ((1 << op) - 1) */

".L_check_window:\n"
"        movq    %%rsi, %%r8\n"           /* save in so from can use it's reg */
"        movq    %%rdi, %%rax\n"
"        subq    40(%%rsp), %%rax\n"      /* nbytes = out - beg */

"        cmpl    %%r15d, %%eax\n"
"        jb      .L_clip_window\n"        /* if (dist > nbytes) 4.2% */

"        movl    %%r14d, %%ecx\n"         /* ecx = len */
"        movq    %%rdi, %%rsi\n"
"        subq    %%r15, %%rsi\n"          /* from = out - dist */

"        sarl    %%ecx\n"
"        jnc     .L_copy_two\n"           /* if len % 2 == 0 */

"        rep     movsw\n"
"        movb    (%%rsi), %%al\n"
"        movb    %%al, (%%rdi)\n"
"        incq    %%rdi\n"

"        movq    %%r8, %%rsi\n"           /* move in back to %rsi, toss from */
"        jmp     .L_while_test\n"

".L_copy_two:\n"
"        rep     movsw\n"
"        movq    %%r8, %%rsi\n"           /* move in back to %rsi, toss from */
"        jmp     .L_while_test\n"

".align 32,0x90\n"
".L_check_dist_one:\n"
"        cmpl    $1, %%r15d\n"            /* if dist 1, is a memset */
"        jne     .L_check_window\n"
"        cmpq    %%rdi, 40(%%rsp)\n"      /* if out == beg, outside window */
"        je      .L_check_window\n"

"        movl    %%r14d, %%ecx\n"         /* ecx = len */
"        movb    -1(%%rdi), %%al\n"
"        movb    %%al, %%ah\n"

"        sarl    %%ecx\n"
"        jnc     .L_set_two\n"
"        movb    %%al, (%%rdi)\n"
"        incq    %%rdi\n"

".L_set_two:\n"
"        rep     stosw\n"
"        jmp     .L_while_test\n"

".align 32,0x90\n"
".L_test_for_second_level_length:\n"
"        testb   $64, %%al\n"
"        jnz     .L_test_for_end_of_block\n" /* if ((op & 64) != 0) */

"        xorl    %%eax, %%eax\n"
"        incl    %%eax\n"
"        shll    %%cl, %%eax\n"
"        decl    %%eax\n"
"        andl    %%edx, %%eax\n"         /* eax &= hold */
"        addl    %%r14d, %%eax\n"        /* eax += len */
"        movl    (%%rbp,%%rax,4), %%eax\n" /* eax = lcode[val+(hold&mask[op])]*/
"        jmp     .L_dolen\n"

".align 32,0x90\n"
".L_test_for_second_level_dist:\n"
"        testb   $64, %%al\n"
"        jnz     .L_invalid_distance_code\n" /* if ((op & 64) != 0) */

"        xorl    %%eax, %%eax\n"
"        incl    %%eax\n"
"        shll    %%cl, %%eax\n"
"        decl    %%eax\n"
"        andl    %%edx, %%eax\n"         /* eax &= hold */
"        addl    %%r15d, %%eax\n"        /* eax += dist */
"        movl    (%%r11,%%rax,4), %%eax\n" /* eax = dcode[val+(hold&mask[op])]*/
"        jmp     .L_dodist\n"

".align 32,0x90\n"
".L_clip_window:\n"
"        movl    %%eax, %%ecx\n"         /* ecx = nbytes */
"        movl    92(%%rsp), %%eax\n"     /* eax = wsize, prepare for dist cmp */
"        negl    %%ecx\n"                /* nbytes = -nbytes */

"        cmpl    %%r15d, %%eax\n"
"        jb      .L_invalid_distance_too_far\n" /* if (dist > wsize) */

"        addl    %%r15d, %%ecx\n"         /* nbytes = dist - nbytes */
"        cmpl    $0, 96(%%rsp)\n"
"        jne     .L_wrap_around_window\n" /* if (write != 0) */

"        movq    56(%%rsp), %%rsi\n"     /* from  = window */
"        subl    %%ecx, %%eax\n"         /* eax  -= nbytes */
"        addq    %%rax, %%rsi\n"         /* from += wsize - nbytes */

"        movl    %%r14d, %%eax\n"        /* eax = len */
"        cmpl    %%ecx, %%r14d\n"
"        jbe     .L_do_copy\n"           /* if (nbytes >= len) */

"        subl    %%ecx, %%eax\n"         /* eax -= nbytes */
"        rep     movsb\n"
"        movq    %%rdi, %%rsi\n"
"        subq    %%r15, %%rsi\n"         /* from = &out[ -dist ] */
"        jmp     .L_do_copy\n"

".align 32,0x90\n"
".L_wrap_around_window:\n"
"        movl    96(%%rsp), %%eax\n"     /* eax = write */
"        cmpl    %%eax, %%ecx\n"
"        jbe     .L_contiguous_in_window\n" /* if (write >= nbytes) */