kolibrios-fun/programs/develop/libraries/utils/trunk/_ftoa.inc

;-----------------------------------------------------------------------------+
; ”ã­ªæ¨ï ¯¥à¥¢®¤  ¢¥é¥á⢥­­®£® ç¨á«  ¢ áâà®ªã      [ by ManHunter / PCL ]   |
;-----------------------------------------------------------------------------|
; <EFBFBD> à ¬¥âàë:                                                                  |
;   lpFloat - 㪠§ â¥«ì ­  ¢¥é¥á⢥­­®¥ ç¨á«® TBYTE                           |
;   lpResult - 㪠§ â¥«ì ­  áâபã-¯à¨¥¬­¨ª १ã«ìâ â                         |
;-----------------------------------------------------------------------------+

proc    FloatToString lpFloat:DWORD, lpResult:DWORD
    ; ‹®ª «ì­ë¥ ¯¥à¥¬¥­­ë¥
    local   digits_count:DWORD
    local   old_cw:WORD
    local   new_cw:WORD
    local   saved_float:TBYTE
    local   tmp1 rb 11h
    local   tmp2 rb 11h

    ; ‘®åà ­¨âì ¢á¥ à¥£¨áâàë
    pusha

    ; “ª § â¥«ì ­  áâபã-¯à¨¥¬­¨ª
    mov     edi,[lpResult]

    ; <EFBFBD>â® ­®«ì?
    lea     esi,[lpFloat]
    cmp     dword [esi],0
    jne     loc_not_zero
    cmp     dword [esi+4],0
    jne     loc_not_zero
    cmp     word [esi+8],0
    jne     loc_not_zero
    ; ‡ ¯¨á âì ¢ áâப㠭®«ì
    mov     al,'0'
    stosb
    jmp     loc_ret

loc_not_zero:
    ; ‘ª®¯¨à®¢ âì ç¨á«® ¢ «®ª «ì­ãî ¯¥à¥¬¥­­ãî
    push    edi
    mov     esi,[lpFloat]
    lea     edi,[saved_float]
    movsd
    movsd
    movsw
    pop     edi
    ; —¨á«® ®âà¨æ â¥«ì­®¥?
    cmp     dword [saved_float+6],0
    jge     loc_not_signed
    ; <EFBFBD>ਢ¥á⨠ç¨á«® ª  ¡á®«îâ­®¬ã §­ ç¥­¨î
    and     byte [saved_float+9],7Fh
    ; ‡ ¯¨á âì ¢ áâப㠬¨­ãá
    mov     al,'-'
    stosb

loc_not_signed:
    ; <EFBFBD>஢¥à¨âì ç¨á«® ­  ­ «¨ç¨¥ ¤à®¡­®© ç á⨠¨
    ; ¯®¤áç¨â âì ª®«¨ç¥á⢮ æ¨äà ¢ ­¥¬
    fclex
    ; ‘®åà ­¨âì ã¯à ¢«ïî饥 á«®¢®
    fstcw   [old_cw]
    ; “áâ ­®¢¨âì ã¯à ¢«ïî饥 á«®¢®
    mov     [new_cw],0000001001111111b
    fldcw   [new_cw]
    lea     esi,[saved_float]
    fld     tbyte [esi]
    fld     st
    ; ‚뤥«¨âì ¬ ­â¨ááã ¨ ¯®à冷ª
    fxtract
    fstp    st
    fldlg2
    ; <EFBFBD>®«ãç¨âì ª®«¨ç¥á⢮ æ¨äà ¢ ç¨á«¥
    fmulp   st1,st
    fistp   [digits_count]
    ; …᫨ æ¨äà ¡®«ìè¥ 16, â® ç¨á«® ®â®¡à ¦ ¥âáï ¢
    ; ­®à¬ «¨§®¢ ­­®¬ ¢¨¤¥ á ¬ ­â¨áᮩ ¨ íªá¯®­¥­â®©
    cmp     [digits_count],10h
    jnb     loc_not_integer
    ; “ ç¨á«  ¥áâì ¤à®¡­ ï ç áâì?
    fld     st
    frndint
    fcomp   st1
    fstsw   ax
    test    ah,01000000b
    ; „ , ®â®¡à ¦ âì ç¨á«® á ¤à®¡­®© ç áâìî
    jz      loc_not_integer

    ; –¥«®¥ ç¨á«® ¡¥§ ¤à®¡­®© ç á⨠¨ íªá¯®­¥­âë
    lea     eax,[tmp1]
    fbstp   [eax]

    ; <EFBFBD>¥à¥¢¥á⨠BCD-ç¨á«® ¢ áâபã
    push    edi
    lea     esi,[tmp1+8]
    lea     edi,[tmp2]
    mov     ecx, 9
@@:
    std
    xor     eax,eax
    lodsb
    cld
    rol     ax,12
    rol     ah,4
    add     ax,'00'
    stosw
    loop    @b
    pop     edi

    ; <EFBFBD>யãáâ¨âì «¨¤¨àãî騩 ­®«ì
    mov     eax,11h
    mov     ecx,[digits_count]
    sub     eax,ecx
    inc     ecx
    lea     esi,[tmp2+eax]
    cmp     byte [esi],'0'
    jne     @f
    inc     esi
    dec     ecx
@@:
    ; <EFBFBD>¥à¥­¥á⨠¯®«ã祭­®¥ ç¨á«® ¨§ ¢à¥¬¥­­®£® ¡ãä¥à 
    rep     movsb
    jmp     loc_clear_stack

loc_not_integer:
    mov     eax,10h
    sub     eax,[digits_count]

    ; <EFBFBD>८¡à §®¢ âì ç¨á«® ¢ 楫®¥ ¤® 16 à §à冷¢
    mov     ecx,eax
    cmp     eax,0
    jge     @f
    neg     eax
@@:
    ; „«ï ç¨á¥« ¡®«ìè¥ 0 ª®à४â¨à®¢ª  ®ªà㣫¥­¨ï ¢ áâ®à®­ã 0
    mov     [new_cw],0000101001111111b
    cmp     ecx,0
    jge     @f
    mov     [new_cw],0000011001111111b
@@:
    ; “áâ ­®¢¨âì ã¯à ¢«ïî饥 á«®¢®
    fldcw   [new_cw]

    ; ‚®§¢¥á⨠10 ¢ á⥯¥­ì ª®«¨ç¥á⢠ æ¨äà
    fld     [float2]
    fld     [float2]
@@:
    fmul    st,st1
    dec     eax
    cmp     eax,1
    ja      @b

    ; <EFBFBD>®ç¨áâ¨âì á⥪
    fxch    st1
    fstp    st

    ; …᫨ ç¨á«® ¬¥­ìè¥ 0, ⮠㬭®¦¨âì, ¨­ ç¥ à §¤¥«¨âì
    cmp     ecx,0
    jge     @f
    fdivp   st1,st
    jmp     loc_rounded
@@:
    fmulp   st1,st

loc_rounded:
    ; <EFBFBD>®«ã祭­®¥ §­ ç¥­¨¥ ¬¥­ìè¥ 1.0e16 ?
    fcom    [float1]
    fstsw   ax
    test    ah,1
    jz      @f
    fmul    [float2]
    dec     [digits_count]
@@:
    ; –¥«®¥ ç¨á«® ¡¥§ ¤à®¡­®© ç á⨠¨ íªá¯®­¥­âë
    lea     eax,[tmp1]
    fbstp   [eax]

    ; <EFBFBD>¥à¥¢¥á⨠BCD-ç¨á«® ¢ áâபã
    push    edi
    lea     esi,[tmp1+8]
    lea     edi,[tmp2]
    mov     ecx, 9
@@:
    std
    xor     eax,eax
    lodsb
    cld
    rol     ax,12
    rol     ah,4
    add     ax,'00'
    stosw
    loop    @b
    pop     edi

    ; —¨á«ã âॡã¥âáï ¬ ­â¨áá  ¨ íªá¯®­¥­â ?
    lea     esi,[tmp2+1]
    mov     ecx,[digits_count]
    cmp     ecx,-0Fh
    jl      loc_mantiss_and_exponent
    cmp     ecx,10h
    jg      loc_mantiss_and_exponent

    ; ‡ ¯®«­¨âì ¤à®¡­ãî ç áâì ç¨á« 
    inc     ecx
    cmp     ecx,0
    jg      @f
    mov     ax,'0.'
    stosw
    neg     ecx
    mov     al,'0'
    rep     stosb
    mov     ecx,10h
    jmp     loc_fraction_filled
@@:
    rep     movsb
    mov     al,'.'
    stosb
    mov     ecx,10h
    sub     ecx,[digits_count]

loc_fraction_filled:
    rep     movsb
    jmp     @f

loc_clear_fraction:
    ; “¤ «¨âì § ¢¥àè î騥 ­ã«¨ ¤à®¡­®© ç áâ¨
    dec     edi
@@:
    cmp     byte [edi-1],'0'
    jz      loc_clear_fraction
    cmp     byte [edi-1],'.'
    jnz     @f
    dec     edi
@@:
    jmp     loc_clear_stack

loc_mantiss_and_exponent:
    ; „஡­ ï ç áâì ¬ ­â¨ááë
    movsb
    mov     al,'.'
    stosb
    movsd
    movsd
    movsw
    ; “¤ «¨âì § ¢¥àè î騥 ­ã«¨ ¤à®¡­®© ç áâ¨
@@:
    cmp     byte [edi-1],'0'
    jne     @f
    cmp     byte [edi-2],'.'
    je      @f
    dec     edi
    jmp     @b
@@:
    ; ‘¨¬¢®« ¨ §­ ª íªá¯®­¥­âë
    mov     al,'e'
    stosb
    mov     al,'+'
    mov     ebx,[digits_count]
    cmp     ebx, 0
    jge     @f
    mov     al,'-'
    neg     ebx
@@:
    stosb

    ; ‡­ ç¥­¨¥ íªá¯®­¥­âë
    mov     eax,ebx
    mov     ecx,10
    mov     ebx,4
@@:
    dec     ebx
    xor     edx,edx
    div     ecx
    add     dl,'0'
    mov     [tmp1+ebx],dl
    or      ebx,ebx
    jnz     @b

    ; <EFBFBD>யãáâ¨âì «¨¤¨àãî騥 ­ã«¨ íªá¯®­¥­âë
    mov     ecx,4
    lea     esi,[tmp1]
@@:
    lodsb
    cmp     al,'0'
    jne     @f
    dec     ecx
    jmp     @b
@@:
    dec     esi
    rep     movsb

loc_clear_stack:
    ; ‚®ááâ ­®¢¨âì ã¯à ¢«ïî饥 á«®¢®
    fldcw   [old_cw]
loc_ret:
    ; Žª®­ç ­¨¥ áâப¨
    mov     al,0
    stosb

    ; ‚®ááâ ­®¢¨âì ¢á¥ à¥£¨áâàë
    popa
    ret

float1  dq      1.0e16
float2  dq      10.0

endp