/*

* inffast.S 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 <christop@charm.net>

* Please use the copyright conditions above.

*

* This version (Jan-23-2003) of inflate_fast was coded and tested under

* GNU/Linux on a pentium 3, using the gcc-3.2 compiler distribution. On that

* machine, I found that gzip style archives decompressed about 20% faster than

* the gcc-3.2 -O3 -fomit-frame-pointer compiled version. Your results will

* depend on how large of a buffer is used for z_stream.next_in & next_out

* (8K-32K worked best for my 256K cpu cache) and how much overhead there is in

* stream processing I/O and crc32/addler32. In my case, this routine used

* 70% of the cpu time and crc32 used 20%.

*

* I am confident that this version will work in the general case, but I have

* not tested a wide variety of datasets or a wide variety of platforms.

*

* Jan-24-2003 -- Added -DUSE_MMX define for slightly faster inflating.

* It should be a runtime flag instead of compile time flag...

*

* Jan-26-2003 -- Added runtime check for MMX support with cpuid instruction.

* With -DUSE_MMX, only MMX code is compiled. With -DNO_MMX, only non-MMX code

* is compiled. Without either option, runtime detection is enabled. Runtime

* detection should work on all modern cpus and the recomended algorithm (flip

* ID bit on eflags and then use the cpuid instruction) is used in many

* multimedia applications. Tested under win2k with gcc-2.95 and gas-2.12

* distributed with cygwin3. Compiling with gcc-2.95 -c inffast.S -o

* inffast.obj generates a COFF object which can then be linked with MSVC++

* compiled code. Tested under FreeBSD 4.7 with gcc-2.95.

*

* Jan-28-2003 -- Tested Athlon XP... MMX mode is slower than no MMX (and

* slower than compiler generated code). Adjusted cpuid check to use the MMX

* code only for Pentiums < P4 until I have more data on the P4. Speed

* improvment is only about 15% on the Athlon when compared with code generated

* with MSVC++. Not sure yet, but I think the P4 will also be slower using the

* MMX mode because many of it's x86 ALU instructions execute in .5 cycles and

* have less latency than MMX ops. Added code to buffer the last 11 bytes of

* the input stream since the MMX code grabs bits in chunks of 32, which

* differs from the inffast.c algorithm. I don't think there would have been

* read overruns where a page boundary was crossed (a segfault), but there

* could have been overruns when next_in ends on unaligned memory (unintialized

* memory read).

*

* Mar-13-2003 -- P4 MMX is slightly slower than P4 NO_MMX. I created a C

* version of the non-MMX code so that it doesn't depend on zstrm and zstate

* structure offsets which are hard coded in this file. This was last tested

* with zlib-1.2.0 which is currently in beta testing, newer versions of this

* and inffas86.c can be found at http://www.eetbeetee.com/zlib/ and

* http://www.charm.net/~christop/zlib/

*/

/*

* if you have underscore linking problems (_inflate_fast undefined), try

* using -DGAS_COFF

*/

#if ! defined( GAS_COFF ) && ! defined( GAS_ELF )

#if defined( WIN32 ) || defined( __CYGWIN__ )

#define GAS_COFF /* windows object format */

#else

#define GAS_ELF

#endif

#endif /* ! GAS_COFF && ! GAS_ELF */

#if defined( GAS_COFF )

/* coff externals have underscores */

#define inflate_fast _inflate_fast

#define inflate_fast_use_mmx _inflate_fast_use_mmx

#endif /* GAS_COFF */

.file "inffast.S"

.globl inflate_fast

.text

.align 4,0

.L_invalid_literal_length_code_msg:

.string "invalid literal/length code"

.align 4,0

.L_invalid_distance_code_msg:

.string "invalid distance code"

.align 4,0

.L_invalid_distance_too_far_msg:

.string "invalid distance too far back"

#if ! defined( NO_MMX )

.align 4,0

.L_mask: /* mask[N] = ( 1 << N ) - 1 */

.long 0

.long 1

.long 3

.long 7

.long 15

.long 31

.long 63

.long 127

.long 255

.long 511

.long 1023

.long 2047

.long 4095

.long 8191

.long 16383

.long 32767

.long 65535

.long 131071

.long 262143

.long 524287

.long 1048575

.long 2097151

.long 4194303

.long 8388607

.long 16777215

.long 33554431

.long 67108863

.long 134217727

.long 268435455

.long 536870911

.long 1073741823

.long 2147483647

.long 4294967295

#endif /* NO_MMX */

.text

/*

* struct z_stream offsets, in zlib.h

*/

#define next_in_strm 0 /* strm->next_in */

#define avail_in_strm 4 /* strm->avail_in */

#define next_out_strm 12 /* strm->next_out */

#define avail_out_strm 16 /* strm->avail_out */

#define msg_strm 24 /* strm->msg */

#define state_strm 28 /* strm->state */

/*

* struct inflate_state offsets, in inflate.h

*/

#define mode_state 0 /* state->mode */

#define wsize_state 32 /* state->wsize */

#define write_state 40 /* state->write */

#define window_state 44 /* state->window */

#define hold_state 48 /* state->hold */

#define bits_state 52 /* state->bits */

#define lencode_state 68 /* state->lencode */

#define distcode_state 72 /* state->distcode */

#define lenbits_state 76 /* state->lenbits */

#define distbits_state 80 /* state->distbits */

/*

* inflate_fast's activation record

*/

#define local_var_size 64 /* how much local space for vars */

#define strm_sp 88 /* first arg: z_stream * (local_var_size + 24) */

#define start_sp 92 /* second arg: unsigned int (local_var_size + 28) */

/*

* offsets for local vars on stack

*/

#define out 60 /* unsigned char* */

#define window 56 /* unsigned char* */

#define wsize 52 /* unsigned int */

#define write 48 /* unsigned int */

#define in 44 /* unsigned char* */

#define beg 40 /* unsigned char* */

#define buf 28 /* char[ 12 ] */

#define len 24 /* unsigned int */

#define last 20 /* unsigned char* */

#define end 16 /* unsigned char* */

#define dcode 12 /* code* */

#define lcode 8 /* code* */

#define dmask 4 /* unsigned int */

#define lmask 0 /* unsigned int */

/*

* typedef enum inflate_mode consts, in inflate.h

*/

#define INFLATE_MODE_TYPE 11 /* state->mode flags enum-ed in inflate.h */

#define INFLATE_MODE_BAD 26

#if ! defined( USE_MMX ) && ! defined( NO_MMX )

#define RUN_TIME_MMX

#define CHECK_MMX 1

#define DO_USE_MMX 2

#define DONT_USE_MMX 3

.globl inflate_fast_use_mmx

.data

.align 4,0

inflate_fast_use_mmx: /* integer flag for run time control 1=check,2=mmx,3=no */

.long CHECK_MMX

#if defined( GAS_ELF )

/* elf info */

.type inflate_fast_use_mmx,@object

.size inflate_fast_use_mmx,4

#endif

#endif /* RUN_TIME_MMX */

#if defined( GAS_COFF )

/* coff info: scl 2 = extern, type 32 = function */

.def inflate_fast; .scl 2; .type 32; .endef

#endif

.text

.align 32,0x90

inflate_fast:

pushl %edi

pushl %esi

pushl %ebp

pushl %ebx

pushf /* save eflags (strm_sp, state_sp assumes this is 32 bits) */

subl $local_var_size, %esp

cld

#define strm_r %esi

#define state_r %edi

movl strm_sp(%esp), strm_r

movl state_strm(strm_r), state_r

/* in = strm->next_in;

* out = strm->next_out;

* last = in + strm->avail_in - 11;

* beg = out - (start - strm->avail_out);

* end = out + (strm->avail_out - 257);

*/

movl avail_in_strm(strm_r), %edx

movl next_in_strm(strm_r), %eax

addl %eax, %edx /* avail_in += next_in */

subl $11, %edx /* avail_in -= 11 */

movl %eax, in(%esp)

movl %edx, last(%esp)

movl start_sp(%esp), %ebp

movl avail_out_strm(strm_r), %ecx

movl next_out_strm(strm_r), %ebx

subl %ecx, %ebp /* start -= avail_out */

negl %ebp /* start = -start */

addl %ebx, %ebp /* start += next_out */

subl $257, %ecx /* avail_out -= 257 */

addl %ebx, %ecx /* avail_out += out */

movl %ebx, out(%esp)

movl %ebp, beg(%esp)

movl %ecx, end(%esp)

/* wsize = state->wsize;

* write = state->write;

* window = state->window;

* hold = state->hold;

* bits = state->bits;

* lcode = state->lencode;

* dcode = state->distcode;

* lmask = ( 1 << state->lenbits ) - 1;

* dmask = ( 1 << state->distbits ) - 1;

*/

movl lencode_state(state_r), %eax

movl distcode_state(state_r), %ecx

movl %eax, lcode(%esp)

movl %ecx, dcode(%esp)

movl $1, %eax

movl lenbits_state(state_r), %ecx

shll %cl, %eax

decl %eax

movl %eax, lmask(%esp)

movl $1, %eax

movl distbits_state(state_r), %ecx

shll %cl, %eax

decl %eax

movl %eax, dmask(%esp)

movl wsize_state(state_r), %eax

movl write_state(state_r), %ecx

movl window_state(state_r), %edx

movl %eax, wsize(%esp)

movl %ecx, write(%esp)

movl %edx, window(%esp)

movl hold_state(state_r), %ebp

movl bits_state(state_r), %ebx

#undef strm_r

#undef state_r

#define in_r %esi

#define from_r %esi

#define out_r %edi

movl in(%esp), in_r

movl last(%esp), %ecx

cmpl in_r, %ecx

ja .L_align_long /* if in < last */

addl $11, %ecx /* ecx = &in[ avail_in ] */

subl in_r, %ecx /* ecx = avail_in */

movl $12, %eax

subl %ecx, %eax /* eax = 12 - avail_in */

leal buf(%esp), %edi

rep movsb /* memcpy( buf, in, avail_in ) */

movl %eax, %ecx

xorl %eax, %eax

rep stosb /* memset( &buf[ avail_in ], 0, 12 - avail_in ) */

leal buf(%esp), in_r /* in = buf */

movl in_r, last(%esp) /* last = in, do just one iteration */

jmp .L_is_aligned

/* align in_r on long boundary */

.L_align_long:

testl $3, in_r

jz .L_is_aligned

xorl %eax, %eax

movb (in_r), %al

incl in_r

movl %ebx, %ecx

addl $8, %ebx

shll %cl, %eax

orl %eax, %ebp

jmp .L_align_long

.L_is_aligned:

movl out(%esp), out_r

#if defined( NO_MMX )

jmp .L_do_loop

#endif

#if defined( USE_MMX )

jmp .L_init_mmx

#endif

/*** Runtime MMX check ***/

#if defined( RUN_TIME_MMX )

.L_check_mmx:

cmpl $DO_USE_MMX, inflate_fast_use_mmx

je .L_init_mmx

ja .L_do_loop /* > 2 */

pushl %eax

pushl %ebx

pushl %ecx

pushl %edx

pushf

movl (%esp), %eax /* copy eflags to eax */

xorl $0x200000, (%esp) /* try toggling ID bit of eflags (bit 21)

* to see if cpu supports cpuid...

* ID bit method not supported by NexGen but

* bios may load a cpuid instruction and

* cpuid may be disabled on Cyrix 5-6x86 */

popf

pushf

popl %edx /* copy new eflags to edx */

xorl %eax, %edx /* test if ID bit is flipped */

jz .L_dont_use_mmx /* not flipped if zero */

xorl %eax, %eax

cpuid

cmpl $0x756e6547, %ebx /* check for GenuineIntel in ebx,ecx,edx */

jne .L_dont_use_mmx

cmpl $0x6c65746e, %ecx

jne .L_dont_use_mmx

cmpl $0x49656e69, %edx

jne .L_dont_use_mmx

movl $1, %eax

cpuid /* get cpu features */

shrl $8, %eax

andl $15, %eax

cmpl $6, %eax /* check for Pentium family, is 0xf for P4 */

jne .L_dont_use_mmx

testl $0x800000, %edx /* test if MMX feature is set (bit 23) */

jnz .L_use_mmx

jmp .L_dont_use_mmx

.L_use_mmx:

movl $DO_USE_MMX, inflate_fast_use_mmx

jmp .L_check_mmx_pop

.L_dont_use_mmx:

movl $DONT_USE_MMX, inflate_fast_use_mmx

.L_check_mmx_pop:

popl %edx

popl %ecx

popl %ebx

popl %eax

jmp .L_check_mmx

#endif

/*** Non-MMX code ***/

#if defined ( NO_MMX ) || defined( RUN_TIME_MMX )

#define hold_r %ebp

#define bits_r %bl

#define bitslong_r %ebx

.align 32,0x90

.L_while_test:

/* while (in < last && out < end)

*/

cmpl out_r, end(%esp)

jbe .L_break_loop /* if (out >= end) */

cmpl in_r, last(%esp)

jbe .L_break_loop

.L_do_loop:

/* regs: %esi = in, %ebp = hold, %bl = bits, %edi = out

*

* do {

* if (bits < 15) {

* hold |= *((unsigned short *)in)++ << bits;

* bits += 16

* }

* this = lcode[hold & lmask]

*/

cmpb $15, bits_r

ja .L_get_length_code /* if (15 < bits) */

xorl %eax, %eax

lodsw /* al = *(ushort *)in++ */

movb bits_r, %cl /* cl = bits, needs it for shifting */

addb $16, bits_r /* bits += 16 */

shll %cl, %eax

orl %eax, hold_r /* hold |= *((ushort *)in)++ << bits */

.L_get_length_code:

movl lmask(%esp), %edx /* edx = lmask */

movl lcode(%esp), %ecx /* ecx = lcode */

andl hold_r, %edx /* edx &= hold */

movl (%ecx,%edx,4), %eax /* eax = lcode[hold & lmask] */

.L_dolen:

/* regs: %esi = in, %ebp = hold, %bl = bits, %edi = out

*

* dolen:

* bits -= this.bits;

* hold >>= this.bits

*/

movb %ah, %cl /* cl = this.bits */

subb %ah, bits_r /* bits -= this.bits */

shrl %cl, hold_r /* hold >>= this.bits */

/* check if op is a literal

* if (op == 0) {

* PUP(out) = this.val;

* }

*/

testb %al, %al

jnz .L_test_for_length_base /* if (op != 0) 45.7% */

shrl $16, %eax /* output this.val char */

stosb

jmp .L_while_test

.L_test_for_length_base:

/* regs: %esi = in, %ebp = hold, %bl = bits, %edi = out, %edx = len

*

* else if (op & 16) {

* len = this.val

* op &= 15

* if (op) {

* if (op > bits) {

* hold |= *((unsigned short *)in)++ << bits;

* bits += 16

* }

* len += hold & mask[op];

* bits -= op;

* hold >>= op;

* }

*/

#define len_r %edx

movl %eax, len_r /* len = this */

shrl $16, len_r /* len = this.val */

movb %al, %cl

testb $16, %al

jz .L_test_for_second_level_length /* if ((op & 16) == 0) 8% */

andb $15, %cl /* op &= 15 */

jz .L_save_len /* if (!op) */

cmpb %cl, bits_r

jae .L_add_bits_to_len /* if (op <= bits) */

movb %cl, %ch /* stash op in ch, freeing cl */

xorl %eax, %eax

lodsw /* al = *(ushort *)in++ */

movb bits_r, %cl /* cl = bits, needs it for shifting */

addb $16, bits_r /* bits += 16 */

shll %cl, %eax

orl %eax, hold_r /* hold |= *((ushort *)in)++ << bits */

movb %ch, %cl /* move op back to ecx */

.L_add_bits_to_len:

movl $1, %eax

shll %cl, %eax

decl %eax

subb %cl, bits_r

andl hold_r, %eax /* eax &= hold */

shrl %cl, hold_r

addl %eax, len_r /* len += hold & mask[op] */

.L_save_len:

movl len_r, len(%esp) /* save len */

#undef len_r

.L_decode_distance:

/* regs: %esi = in, %ebp = hold, %bl = bits, %edi = out, %edx = dist

*

* if (bits < 15) {

* hold |= *((unsigned short *)in)++ << bits;

* bits += 16

* }

* this = dcode[hold & dmask];

* dodist:

* bits -= this.bits;

* hold >>= this.bits;

* op = this.op;

*/

cmpb $15, bits_r

ja .L_get_distance_code /* if (15 < bits) */

xorl %eax, %eax

lodsw /* al = *(ushort *)in++ */

movb bits_r, %cl /* cl = bits, needs it for shifting */

addb $16, bits_r /* bits += 16 */

shll %cl, %eax

orl %eax, hold_r /* hold |= *((ushort *)in)++ << bits */

.L_get_distance_code:

movl dmask(%esp), %edx /* edx = dmask */

movl dcode(%esp), %ecx /* ecx = dcode */

andl hold_r, %edx /* edx &= hold */

movl (%ecx,%edx,4), %eax /* eax = dcode[hold & dmask] */

#define dist_r %edx

.L_dodist:

movl %eax, dist_r /* dist = this */

shrl $16, dist_r /* dist = this.val */

movb %ah, %cl

subb %ah, bits_r /* bits -= this.bits */

shrl %cl, hold_r /* hold >>= this.bits */

/* if (op & 16) {

* dist = this.val

* op &= 15

* if (op > bits) {

* hold |= *((unsigned short *)in)++ << bits;

* bits += 16

* }

* dist += hold & mask[op];

* bits -= op;

* hold >>= op;

*/

movb %al, %cl /* cl = this.op */

testb $16, %al /* if ((op & 16) == 0) */

jz .L_test_for_second_level_dist

andb $15, %cl /* op &= 15 */

jz .L_check_dist_one

cmpb %cl, bits_r

jae .L_add_bits_to_dist /* if (op <= bits) 97.6% */

movb %cl, %ch /* stash op in ch, freeing cl */

xorl %eax, %eax

lodsw /* al = *(ushort *)in++ */

movb bits_r, %cl /* cl = bits, needs it for shifting */

addb $16, bits_r /* bits += 16 */

shll %cl, %eax

orl %eax, hold_r /* hold |= *((ushort *)in)++ << bits */

movb %ch, %cl /* move op back to ecx */

.L_add_bits_to_dist:

movl $1, %eax

shll %cl, %eax

decl %eax /* (1 << op) - 1 */

subb %cl, bits_r

andl hold_r, %eax /* eax &= hold */

shrl %cl, hold_r

addl %eax, dist_r /* dist += hold & ((1 << op) - 1) */

jmp .L_check_window

.L_check_window:

/* regs: %esi = from, %ebp = hold, %bl = bits, %edi = out, %edx = dist

* %ecx = nbytes

*

* nbytes = out - beg;

* if (dist <= nbytes) {

* from = out - dist;

* do {

* PUP(out) = PUP(from);

* } while (--len > 0) {

* }

*/

movl in_r, in(%esp) /* save in so from can use it's reg */

movl out_r, %eax

subl beg(%esp), %eax /* nbytes = out - beg */

cmpl dist_r, %eax

jb .L_clip_window /* if (dist > nbytes) 4.2% */

movl len(%esp), %ecx

movl out_r, from_r

subl dist_r, from_r /* from = out - dist */

subl $3, %ecx

movb (from_r), %al

movb %al, (out_r)

movb 1(from_r), %al

movb 2(from_r), %dl

addl $3, from_r

movb %al, 1(out_r)

movb %dl, 2(out_r)

addl $3, out_r

rep movsb

movl in(%esp), in_r /* move in back to %esi, toss from */

jmp .L_while_test

.align 16,0x90

.L_check_dist_one:

cmpl $1, dist_r

jne .L_check_window

cmpl out_r, beg(%esp)

je .L_check_window

decl out_r

movl len(%esp), %ecx

movb (out_r), %al

subl $3, %ecx

movb %al, 1(out_r)

movb %al, 2(out_r)

movb %al, 3(out_r)

addl $4, out_r

rep stosb

jmp .L_while_test

.align 16,0x90

.L_test_for_second_level_length:

/* else if ((op & 64) == 0) {

* this = lcode[this.val + (hold & mask[op])];

* }

*/

testb $64, %al

jnz .L_test_for_end_of_block /* if ((op & 64) != 0) */

movl $1, %eax

shll %cl, %eax

decl %eax

andl hold_r, %eax /* eax &= hold */

addl %edx, %eax /* eax += this.val */

movl lcode(%esp), %edx /* edx = lcode */

movl (%edx,%eax,4), %eax /* eax = lcode[val + (hold&mask[op])] */

jmp .L_dolen

.align 16,0x90

.L_test_for_second_level_dist:

/* else if ((op & 64) == 0) {

* this = dcode[this.val + (hold & mask[op])];

* }

*/

testb $64, %al

jnz .L_invalid_distance_code /* if ((op & 64) != 0) */

movl $1, %eax

shll %cl, %eax

decl %eax

andl hold_r, %eax /* eax &= hold */

addl %edx, %eax /* eax += this.val */

movl dcode(%esp), %edx /* edx = dcode */

movl (%edx,%eax,4), %eax /* eax = dcode[val + (hold&mask[op])] */

jmp .L_dodist

.align 16,0x90

.L_clip_window:

/* regs: %esi = from, %ebp = hold, %bl = bits, %edi = out, %edx = dist

* %ecx = nbytes

*

* else {

* if (dist > wsize) {

* invalid distance

* }

* from = window;

* nbytes = dist - nbytes;

* if (write == 0) {

* from += wsize - nbytes;

*/

#define nbytes_r %ecx

movl %eax, nbytes_r

movl wsize(%esp), %eax /* prepare for dist compare */

negl nbytes_r /* nbytes = -nbytes */

movl window(%esp), from_r /* from = window */

cmpl dist_r, %eax

jb .L_invalid_distance_too_far /* if (dist > wsize) */

addl dist_r, nbytes_r /* nbytes = dist - nbytes */

cmpl $0, write(%esp)

jne .L_wrap_around_window /* if (write != 0) */

subl nbytes_r, %eax

addl %eax, from_r /* from += wsize - nbytes */

/* regs: %esi = from, %ebp = hold, %bl = bits, %edi = out, %edx = dist

* %ecx = nbytes, %eax = len

*

* if (nbytes < len) {

* len -= nbytes;

* do {

* PUP(out) = PUP(from);

* } while (--nbytes);

* from = out - dist;

* }

* }

*/

#define len_r %eax

movl len(%esp), len_r

cmpl nbytes_r, len_r

jbe .L_do_copy1 /* if (nbytes >= len) */

subl nbytes_r, len_r /* len -= nbytes */

rep movsb

movl out_r, from_r

subl dist_r, from_r /* from = out - dist */

jmp .L_do_copy1

cmpl nbytes_r, len_r

jbe .L_do_copy1 /* if (nbytes >= len) */

subl nbytes_r, len_r /* len -= nbytes */

rep movsb

movl out_r, from_r

subl dist_r, from_r /* from = out - dist */

jmp .L_do_copy1

.L_wrap_around_window:

/* regs: %esi = from, %ebp = hold, %bl = bits, %edi = out, %edx = dist

* %ecx = nbytes, %eax = write, %eax = len

*

* else if (write < nbytes) {

* from += wsize + write - nbytes;

* nbytes -= write;

* if (nbytes < len) {

* len -= nbytes;

* do {

* PUP(out) = PUP(from);

* } while (--nbytes);

* from = window;

* nbytes = write;

* if (nbytes < len) {

* len -= nbytes;

* do {

* PUP(out) = PUP(from);

* } while(--nbytes);

* from = out - dist;

* }

* }

* }

*/

#define write_r %eax

movl write(%esp), write_r

cmpl write_r, nbytes_r

jbe .L_contiguous_in_window /* if (write >= nbytes) */

addl wsize(%esp), from_r

addl write_r, from_r

subl nbytes_r, from_r /* from += wsize + write - nbytes */

subl write_r, nbytes_r /* nbytes -= write */

#undef write_r

movl len(%esp), len_r

cmpl nbytes_r, len_r

jbe .L_do_copy1 /* if (nbytes >= len) */

subl nbytes_r, len_r /* len -= nbytes */

rep movsb

movl window(%esp), from_r /* from = window */

movl write(%esp), nbytes_r /* nbytes = write */

cmpl nbytes_r, len_r

jbe .L_do_copy1 /* if (nbytes >= len) */

subl nbytes_r, len_r /* len -= nbytes */

rep movsb

movl out_r, from_r

subl dist_r, from_r /* from = out - dist */

jmp .L_do_copy1

.L_contiguous_in_window:

/* regs: %esi = from, %ebp = hold, %bl = bits, %edi = out, %edx = dist

* %ecx = nbytes, %eax = write, %eax = len

*

* else {

* from += write - nbytes;

* if (nbytes < len) {

* len -= nbytes;

* do {

* PUP(out) = PUP(from);

* } while (--nbytes);

* from = out - dist;

* }

* }

*/

#define write_r %eax

addl write_r, from_r

subl nbytes_r, from_r /* from += write - nbytes */

#undef write_r

movl len(%esp), len_r

cmpl nbytes_r, len_r

jbe .L_do_copy1 /* if (nbytes >= len) */

subl nbytes_r, len_r /* len -= nbytes */

rep movsb

movl out_r, from_r

subl dist_r, from_r /* from = out - dist */

.L_do_copy1:

/* regs: %esi = from, %esi = in, %ebp = hold, %bl = bits, %edi = out

* %eax = len

*

* while (len > 0) {

* PUP(out) = PUP(from);

* len--;

* }

* }

* } while (in < last && out < end);

*/

#undef nbytes_r

#define in_r %esi

movl len_r, %ecx

rep movsb

movl in(%esp), in_r /* move in back to %esi, toss from */

jmp .L_while_test

#undef len_r

#undef dist_r

#endif /* NO_MMX || RUN_TIME_MMX */

/*** MMX code ***/

#if defined( USE_MMX ) || defined( RUN_TIME_MMX )

.align 32,0x90

.L_init_mmx:

emms

#undef bits_r

#undef bitslong_r

#define bitslong_r %ebp

#define hold_mm %mm0

movd %ebp, hold_mm

movl %ebx, bitslong_r

#define used_mm %mm1

#define dmask2_mm %mm2

#define lmask2_mm %mm3

#define lmask_mm %mm4

#define dmask_mm %mm5

#define tmp_mm %mm6

movd lmask(%esp), lmask_mm

movq lmask_mm, lmask2_mm

movd dmask(%esp), dmask_mm

movq dmask_mm, dmask2_mm

pxor used_mm, used_mm

movl lcode(%esp), %ebx /* ebx = lcode */

jmp .L_do_loop_mmx

.align 32,0x90

.L_while_test_mmx:

/* while (in < last && out < end)

*/

cmpl out_r, end(%esp)

jbe .L_break_loop /* if (out >= end) */

cmpl in_r, last(%esp)

jbe .L_break_loop

.L_do_loop_mmx:

psrlq used_mm, hold_mm /* hold_mm >>= last bit length */

cmpl $32, bitslong_r

ja .L_get_length_code_mmx /* if (32 < bits) */

movd bitslong_r, tmp_mm

movd (in_r), %mm7

addl $4, in_r

psllq tmp_mm, %mm7

addl $32, bitslong_r

por %mm7, hold_mm /* hold_mm |= *((uint *)in)++ << bits */

.L_get_length_code_mmx:

pand hold_mm, lmask_mm

movd lmask_mm, %eax

movq lmask2_mm, lmask_mm

movl (%ebx,%eax,4), %eax /* eax = lcode[hold & lmask] */

.L_dolen_mmx:

movzbl %ah, %ecx /* ecx = this.bits */

movd %ecx, used_mm

subl %ecx, bitslong_r /* bits -= this.bits */

testb %al, %al

jnz .L_test_for_length_base_mmx /* if (op != 0) 45.7% */

shrl $16, %eax /* output this.val char */

stosb

jmp .L_while_test_mmx

.L_test_for_length_base_mmx:

#define len_r %edx

movl %eax, len_r /* len = this */

shrl $16, len_r /* len = this.val */

testb $16, %al

jz .L_test_for_second_level_length_mmx /* if ((op & 16) == 0) 8% */

andl $15, %eax /* op &= 15 */

jz .L_decode_distance_mmx /* if (!op) */

psrlq used_mm, hold_mm /* hold_mm >>= last bit length */

movd %eax, used_mm

movd hold_mm, %ecx

subl %eax, bitslong_r

andl .L_mask(,%eax,4), %ecx

addl %ecx, len_r /* len += hold & mask[op] */

.L_decode_distance_mmx:

psrlq used_mm, hold_mm /* hold_mm >>= last bit length */

cmpl $32, bitslong_r

ja .L_get_dist_code_mmx /* if (32 < bits) */

movd bitslong_r, tmp_mm

movd (in_r), %mm7

addl $4, in_r

psllq tmp_mm, %mm7

addl $32, bitslong_r

por %mm7, hold_mm /* hold_mm |= *((uint *)in)++ << bits */

.L_get_dist_code_mmx:

movl dcode(%esp), %ebx /* ebx = dcode */

pand hold_mm, dmask_mm

movd dmask_mm, %eax

movq dmask2_mm, dmask_mm

movl (%ebx,%eax,4), %eax /* eax = dcode[hold & lmask] */

.L_dodist_mmx:

#define dist_r %ebx

movzbl %ah, %ecx /* ecx = this.bits */

movl %eax, dist_r

shrl $16, dist_r /* dist = this.val */

subl %ecx, bitslong_r /* bits -= this.bits */

movd %ecx, used_mm

testb $16, %al /* if ((op & 16) == 0) */

jz .L_test_for_second_level_dist_mmx

andl $15, %eax /* op &= 15 */

jz .L_check_dist_one_mmx

.L_add_bits_to_dist_mmx:

psrlq used_mm, hold_mm /* hold_mm >>= last bit length */

movd %eax, used_mm /* save bit length of current op */

movd hold_mm, %ecx /* get the next bits on input stream */

subl %eax, bitslong_r /* bits -= op bits */

andl .L_mask(,%eax,4), %ecx /* ecx = hold & mask[op] */

addl %ecx, dist_r /* dist += hold & mask[op] */