boinc/zip/unzip/win32/crc_lcc.asm

120 lines
2.5 KiB
NASM

;===========================================================================
; Copyright (c) 1990-2000 Info-ZIP. All rights reserved.
;
; See the accompanying file LICENSE, version 2000-Apr-09 or later
; (the contents of which are also included in zip.h) for terms of use.
; If, for some reason, all these files are missing, the Info-ZIP license
; also may be found at: ftp://ftp.info-zip.org/pub/infozip/license.html
;===========================================================================
; crc_lcc.asm, optimized CRC calculation function for Zip and UnZip,
; created by Paul Kienitz and Christian Spieler. Last revised 24 Dec 98.
;
; The code in this file has been copied verbatim from crc_i386.{asm|S};
; only the assembler syntax and metacommands have been adapted to
; the habits of the free LCC-Win32 C compiler package.
; This version of the code uses the "optimized for i686" variant of
; crc_i386.{asm|S}.
; IMPORTANT NOTE to the Info-ZIP editors:
; The TAB characters in this source file are required by the parser of
; the LCC-Win32 assembler program and MUST NOT be removed!!
;
; For more information (and a revision log), look into the original
; source files.
;
.text
.file "crc32.c"
.text
.type _crc32,function
_crc32:
pushl %ebp
movl %esp,%ebp
pushl %ecx
pushl %ebx
pushl %esi
pushl %edi
.line 34
.line 37
movl 12(%ebp),%esi
subl %eax,%eax
testl %esi,%esi
jz _$3
.line 39
call _get_crc_table
movl %eax,%edi
.line 41
movl 8(%ebp),%eax
movl 16(%ebp),%ecx
notl %eax
testl %ecx,%ecx
jz _$4
_$5:
testl $3,%esi
jz _$6
xorb (%esi),%al
incl %esi
movzbl %al,%ebx
shrl $8,%eax
xorl (%edi,%ebx,4),%eax
decl %ecx
jnz _$5
_$6:
movl %ecx,%edx
shrl $3,%ecx
jz _$8
_$7:
xorl (%esi),%eax
addl $4,%esi
movzbl %al,%ebx
shrl $8,%eax
xorl (%edi,%ebx,4),%eax
movzbl %al,%ebx
shrl $8,%eax
xorl (%edi,%ebx,4),%eax
movzbl %al,%ebx
shrl $8,%eax
xorl (%edi,%ebx,4),%eax
movzbl %al,%ebx
shrl $8,%eax
xorl (%edi,%ebx,4),%eax
xorl (%esi),%eax
addl $4,%esi
movzbl %al,%ebx
shrl $8,%eax
xorl (%edi,%ebx,4),%eax
movzbl %al,%ebx
shrl $8,%eax
xorl (%edi,%ebx,4),%eax
movzbl %al,%ebx
shrl $8,%eax
xorl (%edi,%ebx,4),%eax
movzbl %al,%ebx
shrl $8,%eax
xorl (%edi,%ebx,4),%eax
decl %ecx
jnz _$7
_$8:
movl %edx,%ecx
andl $7,%ecx
jz _$4
_$9:
xorb (%esi),%al
incl %esi
movzbl %al,%ebx
shrl $8,%eax
xorl (%edi,%ebx,4),%eax
decl %ecx
jnz _$9
_$4:
xorl $0xffffffff,%eax
_$3:
.line 52
popl %edi
popl %esi
popl %ebx
leave
ret
_$34:
.size _crc32,_$34-_crc32
.globl _crc32
.extern _get_crc_table