/*
;uInt longest_match_x64(
; deflate_state *s,
; IPos cur_match); // current match
; gvmat64.S -- Asm portion of the optimized longest_match for 32 bits x86_64
; (AMD64 on Athlon 64, Opteron, Phenom
; and Intel EM64T on Pentium 4 with EM64T, Pentium D, Core 2 Duo, Core I5/I7)
; this file is translation from gvmat64.asm to GCC 4.x (for Linux, Mac XCode)
; Copyright (C) 1995-2010 Jean-loup Gailly, Brian Raiter and Gilles Vollant.
;
; File written by Gilles Vollant, by converting to assembly the longest_match
; from Jean-loup Gailly in deflate.c of zLib and infoZip zip.
; and by taking inspiration on asm686 with masm, optimised assembly code
; from Brian Raiter, written 1998
;
; This software is provided 'as-is', without any express or implied
; warranty. In no event will the authors be held liable for any damages
; arising from the use of this software.
;
; Permission is granted to anyone to use this software for any purpose,
; including commercial applications, and to alter it and redistribute it
; freely, subject to the following restrictions:
;
; 1. The origin of this software must not be misrepresented; you must not
; claim that you wrote the original software. If you use this software
; in a product, an acknowledgment in the product documentation would be
; appreciated but is not required.
; 2. Altered source versions must be plainly marked as such, and must not be
; misrepresented as being the original software
; 3. This notice may not be removed or altered from any source distribution.
;
; http://www.zlib.net
; http://www.winimage.com/zLibDll
; http://www.muppetlabs.com/~breadbox/software/assembly.html
;
; to compile this file for zLib, I use option:
; gcc -c -arch x86_64 gvmat64.S
;uInt longest_match(s, cur_match)
; deflate_state *s;
; IPos cur_match; // current match /
;
; with XCode for Mac, I had strange error with some jump on intel syntax
; this is why BEFORE_JMP and AFTER_JMP are used
*/
#define BEFORE_JMP .att_syntax
#define AFTER_JMP .intel_syntax noprefix
#ifndef NO_UNDERLINE
# define match_init _match_init
# define longest_match _longest_match
#endif
.intel_syntax noprefix
.globl match_init, longest_match
.text
longest_match:
#define LocalVarsSize 96
/*
; register used : rax,rbx,rcx,rdx,rsi,rdi,r8,r9,r10,r11,r12
; free register : r14,r15
; register can be saved : rsp
*/
#define chainlenwmask (rsp + 8 - LocalVarsSize)
#define nicematch (rsp + 16 - LocalVarsSize)
#define save_rdi (rsp + 24 - LocalVarsSize)
#define save_rsi (rsp + 32 - LocalVarsSize)
#define save_rbx (rsp + 40 - LocalVarsSize)
#define save_rbp (rsp + 48 - LocalVarsSize)
#define save_r12 (rsp + 56 - LocalVarsSize)
#define save_r13 (rsp + 64 - LocalVarsSize)
#define save_r14 (rsp + 72 - LocalVarsSize)
#define save_r15 (rsp + 80 - LocalVarsSize)
/*
; all the +4 offsets are due to the addition of pending_buf_size (in zlib
; in the deflate_state structure since the asm code was first written
; (if you compile with zlib 1.0.4 or older, remove the +4).
; Note : these value are good with a 8 bytes boundary pack structure
*/
#define MAX_MATCH 258
#define MIN_MATCH 3
#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
/*
;;; Offsets for fields in the deflate_state structure. These numbers
;;; are calculated from the definition of deflate_state, with the
;;; assumption that the compiler will dword-align the fields. (Thus,
;;; changing the definition of deflate_state could easily cause this
;;; program to crash horribly, without so much as a warning at
;;; compile time. Sigh.)
; all the +zlib1222add offsets are due to the addition of fields
; in zlib in the deflate_state structure since the asm code was first written
; (if you compile with zlib 1.0.4 or older, use "zlib1222add equ (-4)").
; (if you compile with zlib between 1.0.5 and 1.2.2.1, use "zlib1222add equ 0").
; if you compile with zlib 1.2.2.2 or later , use "zlib1222add equ 8").
*/
/* you can check the structure offset by running
#include <stdlib.h>
#include <stdio.h>
#include "deflate.h"
void print_depl()
{
deflate_state ds;
deflate_state *s=&ds;
printf("size pointer=%u\n",(int)sizeof(void*));
printf("#define dsWSize %u\n",(int)(((char*)&(s->w_size))-((char*)s)));
printf("#define dsWMask %u\n",(int)(((char*)&(s->w_mask))-((char*)s)));
printf("#define dsWindow %u\n",(int)(((char*)&(s->window))-((char*)s)));
printf("#define dsPrev %u\n",(int)(((char*)&(s->prev))-((char*)s)));
printf("#define dsMatchLen %u\n",(int)(((char*)&(s->match_length))-((char*)s)));
printf("#define dsPrevMatch %u\n",(int)(((char*)&(s->prev_match))-((char*)s)));
printf("#define dsStrStart %u\n",(int)(((char*)&(s->strstart))-((char*)s)));
printf("#define dsMatchStart %u\n",(int)(((char*)&(s->match_start))-((char*)s)));
printf("#define dsLookahead %u\n",(int)(((char*)&(s->lookahead))-((char*)s)));
printf("#define dsPrevLen %u\n",(int)(((char*)&(s->prev_length))-((char*)s)));
printf("#define dsMaxChainLen %u\n",(int)(((char*)&(s->max_chain_length))-((char*)s)));
printf("#define dsGoodMatch %u\n",(int)(((char*)&(s->good_match))-((char*)s)));
printf("#define dsNiceMatch %u\n",(int)(((char*)&(s->nice_match))-((char*)s)));
}
*/
#define dsWSize 68
#define dsWMask 76
#define dsWindow 80
#define dsPrev 96
#define dsMatchLen 144
#define dsPrevMatch 148
#define dsStrStart 156
#define dsMatchStart 160
#define dsLookahead 164
#define dsPrevLen 168
#define dsMaxChainLen 172
#define dsGoodMatch 188
#define dsNiceMatch 192
#define window_size [ rcx + dsWSize]
#define WMask [ rcx + dsWMask]
#define window_ad [ rcx + dsWindow]
#define prev_ad [ rcx + dsPrev]
#define strstart [ rcx + dsStrStart]
#define match_start [ rcx + dsMatchStart]
#define Lookahead [ rcx + dsLookahead] //; 0ffffffffh on infozip
#define prev_length [ rcx + dsPrevLen]
#define max_chain_length [ rcx + dsMaxChainLen]
#define good_match [ rcx + dsGoodMatch]
#define nice_match [ rcx + dsNiceMatch]
/*
; windows:
; parameter 1 in rcx(deflate state s), param 2 in rdx (cur match)
; see http://weblogs.asp.net/oldnewthing/archive/2004/01/14/58579.aspx and
; http://msdn.microsoft.com/library/en-us/kmarch/hh/kmarch/64bitAMD_8e951dd2-ee77-4728-8702-55ce4b5dd24a.xml.asp
;
; All registers must be preserved across the call, except for
; rax, rcx, rdx, r8, r9, r10, and r11, which are scratch.
;
; gcc on macosx-linux:
; see http://www.x86-64.org/documentation/abi-0.99.pdf
; param 1 in rdi, param 2 in rsi
; rbx, rsp, rbp, r12 to r15 must be preserved
;;; Save registers that the compiler may be using, and adjust esp to
;;; make room for our stack frame.
;;; Retrieve the function arguments. r8d will hold cur_match
;;; throughout the entire function. edx will hold the pointer to the
;;; deflate_state structure during the function's setup (before
;;; entering the main loop.
; ms: parameter 1 in rcx (deflate_state* s), param 2 in edx -> r8 (cur match)
; mac: param 1 in rdi, param 2 rsi
; this clear high 32 bits of r8, which can be garbage in both r8 and rdx
*/
mov [save_rbx],rbx
mov [save_rbp],rbp
mov rcx,rdi
mov r8d,esi
mov [save_r12],r12
mov [save_r13],r13
mov [save_r14],r14
mov [save_r15],r15
//;;; uInt wmask = s->w_mask;
//;;; unsigned chain_length = s->max_chain_length;
//;;; if (s->prev_length >= s->good_match) {
//;;; chain_length >>= 2;
//;;; }
mov edi, prev_length
mov esi, good_match
mov eax, WMask
mov ebx, max_chain_length
cmp edi, esi
jl LastMatchGood
shr ebx, 2
LastMatchGood:
//;;; chainlen is decremented once beforehand so that the function can
//;;; use the sign flag instead of the zero flag for the exit test.
//;;; It is then shifted into the high word, to make room for the wmask
//;;; value, which it will always accompany.
dec ebx
shl ebx, 16
or ebx, eax
//;;; on zlib only
//;;; if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
mov eax, nice_match
mov [chainlenwmask], ebx
mov r10d, Lookahead
cmp r10d, eax
cmovnl r10d, eax
mov [nicematch],r10d
//;;; register Bytef *scan = s->window + s->strstart;
mov r10, window_ad
mov ebp, strstart
lea r13, [r10 + rbp]
//;;; Determine how many bytes the scan ptr is off from being
//;;; dword-aligned.
mov r9,r13
neg r13
and r13,3
//;;; IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
//;;; s->strstart - (IPos)MAX_DIST(s) : NIL;
mov eax, window_size
sub eax, MIN_LOOKAHEAD
xor edi,edi
sub ebp, eax
mov r11d, prev_length
cmovng ebp,edi
//;;; int best_len = s->prev_length;
//;;; Store the sum of s->window + best_len in esi locally, and in esi.
lea rsi,[r10+r11]
//;;; register ush scan_start = *(ushf*)scan;
//;;; register ush scan_end = *(ushf*)(scan+best_len-1);
//;;; Posf *prev = s->prev;
movzx r12d,word ptr [r9]
movzx ebx, word ptr [r9 + r11 - 1]
mov rdi, prev_ad
//;;; Jump into the main loop.
mov edx, [chainlenwmask]
cmp bx,word ptr [rsi + r8 - 1]
jz LookupLoopIsZero
LookupLoop1:
and r8d, edx
movzx r8d, word ptr [rdi + r8*2]
cmp r8d, ebp
jbe LeaveNow
sub edx, 0x00010000
BEFORE_JMP
js LeaveNow
AFTER_JMP
LoopEntry1:
cmp bx,word ptr [rsi + r8 - 1]
BEFORE_JMP
jz LookupLoopIsZero
AFTER_JMP
LookupLoop2:
and r8d, edx
movzx r8d, word ptr [rdi + r8*2]
cmp r8d, ebp
BEFORE_JMP
jbe LeaveNow
AFTER_JMP
sub edx, 0x00010000
BEFORE_JMP
js LeaveNow
AFTER_JMP
LoopEntry2:
cmp bx,word ptr [rsi + r8 - 1]
BEFORE_JMP
jz LookupLoopIsZero
AFTER_JMP
LookupLoop4:
and r8d, edx
movzx r8d, word ptr [rdi + r8*2]
cmp r8d, ebp
BEFORE_JMP
jbe LeaveNow
AFTER_JMP
sub edx, 0x00010000
BEFORE_JMP
js LeaveNow
AFTER_JMP
LoopEntry4:
cmp bx,word ptr [rsi + r8 - 1]
BEFORE_JMP
jnz LookupLoop1
jmp LookupLoopIsZero
AFTER_JMP
/*
;;; do {
;;; match = s->window + cur_match;
;;; if (*(ushf*)(match+best_len-1) != scan_end ||
;;; *(ushf*)match != scan_start) continue;
;;; [...]
;;; } while ((cur_match = prev[cur_match & wmask]) > limit
;;; && --chain_length != 0);
;;;
;;; Here is the inner loop of the function. The function will spend the
;;; majority of its time in this loop, and majority of that time will
;;; be spent in the first ten instructions.
;;;
;;; Within this loop:
;;; ebx = scanend
;;; r8d = curmatch
;;; edx = chainlenwmask - i.e., ((chainlen << 16) | wmask)
;;; esi = windowbestlen - i.e., (window + bestlen)
;;; edi = prev
;;; ebp = limit
*/
.balign 16
LookupLoop:
and r8d, edx
movzx r8d, word ptr [rdi + r8*2]
cmp r8d, ebp
BEFORE_JMP
jbe LeaveNow
AFTER_JMP
sub edx, 0x00010000
BEFORE_JMP
js LeaveNow
AFTER_JMP
LoopEntry:
cmp bx,word ptr [rsi + r8 - 1]
BEFORE_JMP
jnz LookupLoop1
AFTER_JMP
LookupLoopIsZero:
cmp r12w, word ptr [r10 + r8]
BEFORE_JMP
jnz LookupLoop1
AFTER_JMP
//;;; Store the current value of chainlen.
mov [chainlenwmask], edx
/*
;;; Point edi to the string under scrutiny, and esi to the string we
;;; are hoping to match it up with. In actuality, esi and edi are
;;; both pointed (MAX_MATCH_8 - scanalign) bytes ahead, and edx is
;;; initialized to -(MAX_MATCH_8 - scanalign).
*/
lea rsi,[r8+r10]
mov rdx, 0xfffffffffffffef8 //; -(MAX_MATCH_8)
lea rsi, [rsi + r13 + 0x0108] //;MAX_MATCH_8]
lea rdi, [r9 + r13 + 0x0108] //;MAX_MATCH_8]
prefetcht1 [rsi+rdx]
prefetcht1 [rdi+rdx]
/*
;;; Test the strings for equality, 8 bytes at a time. At the end,
;;; adjust rdx so that it is offset to the exact byte that mismatched.
;;;
;;; We already know at this point that the first three bytes of the
;;; strings match each other, and they can be safely passed over before
;;; starting the compare loop. So what this code does is skip over 0-3
;;; bytes, as much as necessary in order to dword-align the edi
;;; pointer. (rsi will still be misaligned three times out of four.)
;;;
;;; It should be confessed that this loop usually does not represent
;;; much of the total running time. Replacing it with a more
;;; straightforward "rep cmpsb" would not drastically degrade
;;; performance.
*/
LoopCmps:
mov rax, [rsi + rdx]
xor rax, [rdi + rdx]
jnz LeaveLoopCmps
mov rax, [rsi + rdx + 8]
xor rax, [rdi + rdx + 8]
jnz LeaveLoopCmps8
mov rax, [rsi + rdx + 8+8]
xor rax, [rdi + rdx + 8+8]
jnz LeaveLoopCmps16
add rdx,8+8+8
BEFORE_JMP
jnz LoopCmps
jmp LenMaximum
AFTER_JMP
LeaveLoopCmps16: add rdx,8
LeaveLoopCmps8: add rdx,8
LeaveLoopCmps:
test eax, 0x0000FFFF
jnz LenLower
test eax,0xffffffff
jnz LenLower32
add rdx,4
shr rax,32
or ax,ax
BEFORE_JMP
jnz LenLower
AFTER_JMP
LenLower32:
shr eax,16
add rdx,2
LenLower:
sub al, 1
adc rdx, 0
//;;; Calculate the length of the match. If it is longer than MAX_MATCH,
//;;; then automatically accept it as the best possible match and leave.
lea rax, [rdi + rdx]
sub rax, r9
cmp eax, MAX_MATCH
BEFORE_JMP
jge LenMaximum
AFTER_JMP
/*
;;; If the length of the match is not longer than the best match we
;;; have so far, then forget it and return to the lookup loop.
;///////////////////////////////////
*/
cmp eax, r11d
jg LongerMatch
lea rsi,[r10+r11]
mov rdi, prev_ad
mov edx, [chainlenwmask]
BEFORE_JMP
jmp LookupLoop
AFTER_JMP
/*
;;; s->match_start = cur_match;
;;; best_len = len;
;;; if (len >= nice_match) break;
;;; scan_end = *(ushf*)(scan+best_len-1);
*/
LongerMatch:
mov r11d, eax
mov match_start, r8d
cmp eax, [nicematch]
BEFORE_JMP
jge LeaveNow
AFTER_JMP
lea rsi,[r10+rax]
movzx ebx, word ptr [r9 + rax - 1]
mov rdi, prev_ad
mov edx, [chainlenwmask]
BEFORE_JMP
jmp LookupLoop
AFTER_JMP
//;;; Accept the current string, with the maximum possible length.
LenMaximum:
mov r11d,MAX_MATCH
mov match_start, r8d
//;;; if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
//;;; return s->lookahead;
LeaveNow:
mov eax, Lookahead
cmp r11d, eax
cmovng eax, r11d
//;;; Restore the stack and return from whence we came.
// mov rsi,[save_rsi]
// mov rdi,[save_rdi]
mov rbx,[save_rbx]
mov rbp,[save_rbp]
mov r12,[save_r12]
mov r13,[save_r13]
mov r14,[save_r14]
mov r15,[save_r15]
ret 0
//; please don't remove this string !
//; Your can freely use gvmat64 in any free or commercial app
//; but it is far better don't remove the string in the binary!
// db 0dh,0ah,"asm686 with masm, optimised assembly code from Brian Raiter, written 1998, converted to amd 64 by Gilles Vollant 2005",0dh,0ah,0
match_init:
ret 0