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私はFP IEEE-754をMASMアセンブリのStrDecに取り組んでいます。それはうまくいきますが、実際に私がこのことを考え出したにもかかわらず、コンマの後に数字を追加する方法がわからない - 123.46のように2つありますが、123.456789が必要です。私は私の余分なビットを処理するためにカウンタが必要だと思うが、私はaccess violationを得て、カンマの後に余分な数字を加えてバイト数を増やしている。StrDecへの浮動小数点
.data
CaptionOut BYTE "Result: ", 0
temp_bcd dt ?
szdecimal db 32 dup(0)
MyNum REAL10 123.456789
.code
main PROC
; FPU to DecStr
fld MyNum
pushd 100 ;use the stack as storage for this value
fimul dword ptr[esp] ;converts 2 decimal places as 2 more integer digits
fbstp temp_bcd ;store the packed BCD integer value
pop eax ;clean the stack of the pushed 100
; ESI will be used for pointing to the packed BCD
; EDI will be used for pointing to the decimal string
push esi
push edi
lea esi,temp_bcd+9 ;point to the most significant byte
lea edi,szdecimal ;point to the start of the decimal string buffer
xor eax,eax
fwait ;to ascertain that the transfer of the
;packed BCD is completed
mov al,[esi] ;get the byte with the sign code
dec esi ;decrement to next most significant byte
or al,al ;for checking the sign bit
jns @F ;jump if no sign bit
mov al,"-" ;the value is negative
stosb ;insert the negative sign
@@:
; The next 8 bytes (in this example) will contain the integer digits
; and the least significant byte will then contain the 2 decimal digits.
; No leading 0 will be included in the integer portion
; unless it would be the only integer digit.
mov ecx,8 ;number of bytes to process for integer digits
@@:
mov al,[esi] ;get the next byte
dec esi ;adjust the pointer to the next one
or al,al ;for checking if it is 0
jnz @F ;the starting integer digit is now in AL
dec ecx ;adjust the counter of integer bytes
jnz @B ;continue searching for the first integer digit
; If the loop terminates with ECX=0, the integer portion would be 0.
; A "0" character must be inserted before processing the decimal digits
mov al,"0" ;the ASCII 0
stosb ;insert it
mov al,[esi] ;get the byte containing the decimal digits
jmp decimal_digits
@@:
; The first integer byte must be checked to determine
; if it contains 1 or 2 integer digits
test al,0f0h ;test if the H.O. nibble contains a digit
jz int_digit2 ;if not, process only the L.O. nibble
int_digit1:
ror ax,4 ;puts the H.O. nibble in the L.O. nibble position
;and saves the L.O. nibble in AH
add al,30h ;convert it to ASCII character
stosb ;store this character
shr ax,12 ;restores the L.O. nibble in AL
;and also resets the other bits of AX
int_digit2:
add al,30h ;convert it to ASCII character
stosb ;store this character
mov al,[esi] ;get next byte
dec esi ;adjust the pointer to the next one
dec ecx ;adjust the counter of integer bytes
jnz int_digit1 ;continue processing the integer bytes
decimal_digits:
mov byte ptr [edi],"." ;insert the preferred decimal delimiter
inc edi
; Also, if the number of required decimal digits is not even, the code
; would have to be altered to insert the decimal delimiter at the
; proper location.
ror ax,4 ;puts the H.O. nibble in the L.O. nibble position
;and saves the L.O. nibble in AH
add al,30h ;convert it to ASCII character
stosb ;store this character
shr ax,12 ;restores the L.O. nibble in AL
;and also resets the other bits of AX
add al,30h ;convert it to ASCII character
stosw ;store this character + the terminating 0
INVOKE MessageBoxA, 0, ADDR szdecimal, ADDR CaptionOut, 0
INVOKE ExitProcess,0
main ENDP
END main
任意のヘルプやアイデアをありがとう！