deps/zlib/contrib/masmx64/inffasx64.asm

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; 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