; inffasx64.asm is a hand tuned assembler version of inffast.c - fast decoding
; version for AMD64 on Windows using Microsoft C compiler
;
; inffasx64.asm is automatically convert from AMD64 portion of inffas86.c
; inffasx64.asm is called by inffas8664.c, which contain more info.
; to compile this file, I use option
; ml64.exe /Flinffasx64 /c /Zi inffasx64.asm
; with Microsoft Macro Assembler (x64) for AMD64
;
; This file compile with Microsoft Macro Assembler (x64) for AMD64
;
; ml64.exe is given with Visual Studio 2005/2008/2010 and Windows WDK
;
; (you can get Windows WDK with ml64 for AMD64 from
; http://www.microsoft.com/whdc/Devtools/wdk/default.mspx for low price)
;
.code
inffas8664fnc PROC
; 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, r-9, r10, and r11, which are scratch.
mov [rsp-8],rsi
mov [rsp-16],rdi
mov [rsp-24],r12
mov [rsp-32],r13
mov [rsp-40],r14
mov [rsp-48],r15
mov [rsp-56],rbx
mov rax,rcx
mov [rax+8], rbp ; /* save regs rbp and rsp */
mov [rax], rsp
mov rsp, rax ; /* make rsp point to &ar */
mov rsi, [rsp+16] ; /* rsi = in */
mov rdi, [rsp+32] ; /* rdi = out */
mov r9, [rsp+24] ; /* r9 = last */
mov r10, [rsp+48] ; /* r10 = end */
mov rbp, [rsp+64] ; /* rbp = lcode */
mov r11, [rsp+72] ; /* r11 = dcode */
mov rdx, [rsp+80] ; /* rdx = hold */
mov ebx, [rsp+88] ; /* ebx = bits */
mov r12d, [rsp+100] ; /* r12d = lmask */
mov r13d, [rsp+104] ; /* r13d = dmask */
; /* r14d = len */
; /* r15d = dist */
cld
cmp r10, rdi
je L_one_time ; /* if only one decode left */
cmp r9, rsi
jne L_do_loop
L_one_time:
mov r8, r12 ; /* r8 = lmask */
cmp bl, 32
ja L_get_length_code_one_time
lodsd ; /* eax = *(uint *)in++ */
mov cl, bl ; /* cl = bits, needs it for shifting */
add bl, 32 ; /* bits += 32 */
shl rax, cl
or rdx, rax ; /* hold |= *((uint *)in)++ << bits */
jmp L_get_length_code_one_time
ALIGN 4
L_while_test:
cmp r10, rdi
jbe L_break_loop
cmp r9, rsi
jbe L_break_loop
L_do_loop:
mov r8, r12 ; /* r8 = lmask */
cmp bl, 32
ja L_get_length_code ; /* if (32 < bits) */
lodsd ; /* eax = *(uint *)in++ */
mov cl, bl ; /* cl = bits, needs it for shifting */
add bl, 32 ; /* bits += 32 */
shl rax, cl
or rdx, rax ; /* hold |= *((uint *)in)++ << bits */
L_get_length_code:
and r8, rdx ; /* r8 &= hold */
mov eax, [rbp+r8*4] ; /* eax = lcode[hold & lmask] */
mov cl, ah ; /* cl = this.bits */
sub bl, ah ; /* bits -= this.bits */
shr rdx, cl ; /* hold >>= this.bits */
test al, al
jnz L_test_for_length_base ; /* if (op != 0) 45.7% */
mov r8, r12 ; /* r8 = lmask */
shr eax, 16 ; /* output this.val char */
stosb
L_get_length_code_one_time:
and r8, rdx ; /* r8 &= hold */
mov eax, [rbp+r8*4] ; /* eax = lcode[hold & lmask] */
L_dolen:
mov cl, ah ; /* cl = this.bits */
sub bl, ah ; /* bits -= this.bits */
shr rdx, cl ; /* hold >>= this.bits */
test al, al
jnz L_test_for_length_base ; /* if (op != 0) 45.7% */
shr eax, 16 ; /* output this.val char */
stosb
jmp L_while_test
ALIGN 4
L_test_for_length_base:
mov r14d, eax ; /* len = this */
shr r14d, 16 ; /* len = this.val */
mov cl, al
test al, 16
jz L_test_for_second_level_length ; /* if ((op & 16) == 0) 8% */
and cl, 15 ; /* op &= 15 */
jz L_decode_distance ; /* if (!op) */
L_add_bits_to_len:
sub bl, cl
xor eax, eax
inc eax
shl eax, cl
dec eax
and eax, edx ; /* eax &= hold */
shr rdx, cl
add r14d, eax ; /* len += hold & mask[op] */
L_decode_distance:
mov r8, r13 ; /* r8 = dmask */
cmp bl, 32
ja L_get_distance_code ; /* if (32 < bits) */
lodsd ; /* eax = *(uint *)in++ */
mov cl, bl ; /* cl = bits, needs it for shifting */
add bl, 32 ; /* bits += 32 */
shl rax, cl
or rdx, rax ; /* hold |= *((uint *)in)++ << bits */
L_get_distance_code:
and r8, rdx ; /* r8 &= hold */
mov eax, [r11+r8*4] ; /* eax = dcode[hold & dmask] */
L_dodist:
mov r15d, eax ; /* dist = this */
shr r15d, 16 ; /* dist = this.val */
mov cl, ah
sub bl, ah ; /* bits -= this.bits */
shr rdx, cl ; /* hold >>= this.bits */
mov cl, al ; /* cl = this.op */
test al, 16 ; /* if ((op & 16) == 0) */
jz L_test_for_second_level_dist
and cl, 15 ; /* op &= 15 */
jz L_check_dist_one
L_add_bits_to_dist:
sub bl, cl
xor eax, eax
inc eax
shl eax, cl
dec eax ; /* (1 << op) - 1 */
and eax, edx ; /* eax &= hold */
shr rdx, cl
add r15d, eax ; /* dist += hold & ((1 << op) - 1) */
L_check_window:
mov r8, rsi ; /* save in so from can use it's reg */
mov rax, rdi
sub rax, [rsp+40] ; /* nbytes = out - beg */
cmp eax, r15d
jb L_clip_window ; /* if (dist > nbytes) 4.2% */
mov ecx, r14d ; /* ecx = len */
mov rsi, rdi
sub rsi, r15 ; /* from = out - dist */
sar ecx, 1
jnc L_copy_two ; /* if len % 2 == 0 */
rep movsw
mov al, [rsi]
mov [rdi], al
inc rdi
mov rsi, r8 ; /* move in back to %rsi, toss from */
jmp L_while_test
L_copy_two:
rep movsw
mov rsi, r8 ; /* move in back to %rsi, toss from */
jmp L_while_test
ALIGN 4
L_check_dist_one:
cmp r15d, 1 ; /* if dist 1, is a memset */
jne L_check_window
cmp [rsp+40], rdi ; /* if out == beg, outside window */
je L_check_window
mov ecx, r14d ; /* ecx = len */
mov al, [rdi-1]
mov ah, al
sar ecx, 1
jnc L_set_two
mov [rdi], al
inc rdi
L_set_two:
rep stosw
jmp L_while_test
ALIGN 4
L_test_for_second_level_length:
test al, 64
jnz L_test_for_end_of_block ; /* if ((op & 64) != 0) */
xor eax, eax
inc eax
shl eax, cl
dec eax
and eax, edx ; /* eax &= hold */
add eax, r14d ; /* eax += len */
mov eax, [rbp+rax*4] ; /* eax = lcode[val+(hold&mask[op])]*/
jmp L_dolen
ALIGN 4
L_test_for_second_level_dist:
test al, 64
jnz L_invalid_distance_code ; /* if ((op & 64) != 0) */
xor eax, eax
inc eax
shl eax, cl
dec eax
and eax, edx ; /* eax &= hold */
add eax, r15d ; /* eax += dist */
mov eax, [r11+rax*4] ; /* eax = dcode[val+(hold&mask[op])]*/
jmp L_dodist
ALIGN 4
L_clip_window:
mov ecx, eax ; /* ecx = nbytes */
mov eax, [rsp+92] ; /* eax = wsize, prepare for dist cmp */
neg ecx ; /* nbytes = -nbytes */
cmp eax, r15d
jb L_invalid_distance_too_far ; /* if (dist > wsize) */
add ecx, r15d ; /* nbytes = dist - nbytes */
cmp dword ptr [rsp+96], 0
jne L_wrap_around_window ; /* if (write != 0) */
mov rsi, [rsp+56] ; /* from = window */
sub eax, ecx ; /* eax -= nbytes */
add rsi, rax ; /* from += wsize - nbytes */
mov eax, r14d ; /* eax = len */
cmp r14d, ecx
jbe L_do_copy ; /* if (nbytes >= len) */
sub eax, ecx ; /* eax -= nbytes */
rep movsb
mov rsi, rdi
sub rsi, r15 ; /* from = &out[ -dist ] */
jmp L_do_copy
ALIGN 4
L_wrap_around_window:
mov eax, [rsp+96] ; /* eax = write */
cmp ecx, eax
jbe L_contiguous_in_window ; /* if (write >= nbytes) */
mov esi, [rsp+92] ; /* from = wsize */
add rsi, [rsp+56] ; /* from += window */
add rsi, rax ; /* from += write */
sub rsi, rcx ; /* from -= nbytes */
sub ecx, eax ; /* nbytes -= write */
mov eax, r14d ; /* eax = len */
cmp eax, ecx
jbe L_do_copy ; /* if (nbytes >= len) */
sub eax, ecx ; /* len -= nbytes */
rep movsb
mov rsi, [rsp+56] ; /* from = window */
mov ecx, [rsp+96] ; /* nbytes = write */
cmp eax, ecx
jbe L_do_copy ; /* if (nbytes >= len) */
sub eax, ecx ; /* len -= nbytes */
rep movsb
mov rsi, rdi
sub rsi, r15 ; /* from = out - dist */
jmp L_do_copy
ALIGN 4
L_contiguous_in_window:
mov rsi, [rsp+56] ; /* rsi = window */
add rsi, rax
sub rsi, rcx ; /* from += write - nbytes */
mov eax, r14d ; /* eax = len */
cmp eax, ecx
jbe L_do_copy ; /* if (nbytes >= len) */
sub eax, ecx ; /* len -= nbytes */
rep movsb
mov rsi, rdi
sub rsi, r15 ; /* from = out - dist */
jmp L_do_copy ; /* if (nbytes >= len) */
ALIGN 4
L_do_copy:
mov ecx, eax ; /* ecx = len */
rep movsb
mov rsi, r8 ; /* move in back to %esi, toss from */
jmp L_while_test
L_test_for_end_of_block:
test al, 32
jz L_invalid_literal_length_code
mov dword ptr [rsp+116], 1
jmp L_break_loop_with_status
L_invalid_literal_length_code:
mov dword ptr [rsp+116], 2
jmp L_break_loop_with_status
L_invalid_distance_code:
mov dword ptr [rsp+116], 3
jmp L_break_loop_with_status
L_invalid_distance_too_far:
mov dword ptr [rsp+116], 4
jmp L_break_loop_with_status
L_break_loop:
mov dword ptr [rsp+116], 0
L_break_loop_with_status:
; /* put in, out, bits, and hold back into ar and pop esp */
mov [rsp+16], rsi ; /* in */
mov [rsp+32], rdi ; /* out */
mov [rsp+88], ebx ; /* bits */
mov [rsp+80], rdx ; /* hold */
mov rax, [rsp] ; /* restore rbp and rsp */
mov rbp, [rsp+8]
mov rsp, rax
mov rsi,[rsp-8]
mov rdi,[rsp-16]
mov r12,[rsp-24]
mov r13,[rsp-32]
mov r14,[rsp-40]
mov r15,[rsp-48]
mov rbx,[rsp-56]
ret 0
; :
; : "m" (ar)
; : "memory", "%rax", "%rbx", "%rcx", "%rdx", "%rsi", "%rdi",
; "%r8", "%r9", "%r10", "%r11", "%r12", "%r13", "%r14", "%r15"
; );
inffas8664fnc ENDP
;_TEXT ENDS
END