📽️ 🖕🏿 🤛🏽 Convertir una cadena de caracteres en un doble 👶🏿 🤳🏼 🤜

Convierta la cadena de caracteres a doble precisión en MASM64 sin usar FPU usando las instrucciones SSE4.1. El formato del número corresponde al formato aceptado por el compilador ML64.EXE

1. Configuración de convenciones de compilación, direccionamiento y llamada.

1.1. .

x64 software conventions

RCX

.

1.2. .

x64

x32

. . /LARGEADDRESSAWARE:NO

.

2. Constantes de texto y alias.

2.1.

() «» :

BUFF_STR  equ esp - xmmword * 4

2.2. .

DWORD

INT

, , «» «» :

;  
CUR_CHAR  equ  ecx	      ;    
DOT_CHAR  equ  edx        ;    
HASH_STR  equ  r8d        ;    
END_CHAR  equ  HASH_STR   ;    
N_Z_CHAR  equ  r9d        ;      
OFF_CHAR  equ  N_Z_CHAR   ;       
END_FRAC  equ  r10d       ;      
EXP_CHAR  equ  END_FRAC   ;     
LEN_NUMB  equ  r11d       ;    
LEN_CELL  equ  LEN_NUMB   ;    

HASH_MUL  equ  ebx        ;      
MANT_ARG  equ  r8         ;   
LOGB_ARG  equ  r9d        ;   
MANT_MUL  equ  r10        ;  
LOGB_MUL  equ  r11d       ;

3. Sección de datos

. «» , , SIMD

, :

.data
Xmm_HT     byte 10h dup (09h)
Xmm_CR     byte 10h dup (0Dh)
Xmm_SP     byte 10h dup (20h)
Xmm_SL     byte 10h dup ('/')
Xmm_30     byte 10h dup ('0')
Xmm_39     byte 10h dup ('9')

Xmm_0001   word  8  dup      (010Ah)
Xmm_0010  dword  4  dup     (10064h)
Xmm_0100  qword  2  dup (100002710h)

Mask_001   word  0044h, 0944h, 0D44h, 2044h, 0046h, 0946h, 0D46h, 2046h
Mask_010   word  0064h, 0964h, 0D64h, 2064h, 0066h, 0966h, 0D66h, 2066h

Mul_0001  qword  0E8D4A51000h

Plus       word  2B00h

;  
string     byte  '	 ', 0Dh, 0Ah, '+-0098765432109876540.09876e-0248 '

4. Sección de código.

4.1. .

4.1.1.

4.1.1.1. .

— 3

3

-1

.

— CUR_CHAR

.

— CUR_CHAR

.

	pcmpeqb  xmm3, xmm3
	sub  CUR_CHAR, xmmword 
@@:	add  CUR_CHAR, xmmword

, -

, 15 . , , . .

4.1.1.2. .

— 0

1

/ 2

.

— ,

/

/

— 0

.

movdqu   xmm0,[CUR_CHAR]
movdqa   xmm1, xmm0
movdqa   xmm2, xmm0
pcmpeqb  xmm0, xmmword ptr Xmm_SP
pcmpeqb  xmm1, xmmword ptr Xmm_HT
pcmpeqb  xmm2, xmmword ptr Xmm_CR
paddb    xmm0, xmm1
paddb    xmm0, xmm2

0

-1

0

. «» .

4.1.1.3. .

— PTEST

AND

0

3

-1

CF=1

.

— CF=1

.

ptest    xmm0, xmm3
jc  @b	;

.

/

/

SIMD

, 64

, , .

4.1.2. .

- 0

EAX

, 1

.

— EAX

, 1

.

— EAX

1

, , .

— EAX

CUR_CHAR

.

pmovmskb  eax, xmm0
not       eax
bsf       eax, eax
add  CUR_CHAR, eax

4.1.3. .

— ZF=1

.

— EAX

1

ZF=1

0

.

— EAX

CUR_CHAR

.

cmp   word ptr[CUR_CHAR - byte], 0A0Dh
setz  al
add  CUR_CHAR, eax

, .

4.1.4. .

— EAX

.

— ZF=1

EAX

0

.

— ZF=1

:

movzx  eax, byte ptr[CUR_CHAR]
test    al, al
jz  ErrorExit	;

4.2. .

4.2.1. .

— AL

.

— AL

1

AL

0

.

— EAX

CUR_CHAR

.

cmp     al, '+'
setz    al
add    CUR_CHAR, eax

, .

4.2.2. .

—

.

— AL

1

0

.

— EAX

CUR_CHAR

.

— EAX

ESP

.

cmp    byte ptr[CUR_CHAR], '-'
setz    al
add    CUR_CHAR, eax
add    esp, eax

, ESP

1

, , . ESP

, «» «» «» , , , .

4.3. .

4.3.1. .

4.3.1.1. .

— , 16 , 0

.

— 1

2

.

— 0

9

.

— 0

1.

movdqu   xmm0,[CUR_CHAR + xmmword]
movdqa   xmm2, xmm0
movdqa   xmm3, xmm0
pcmpgtb  xmm0, xmmword ptr Xmm_39
movdqa   xmm1, xmm0

0

1

9

-1

, 0

.

4.3.1.2. .

— 2

, 2

0

-1

, 0

.

— PANDN

0

AND

0

2

0

.

pcmpgtb  xmm2, xmmword ptr Xmm_SL
pandn    xmm0, xmm2

0

0

9

,

, -1

0

.

4.3.1.3. .

— 3

0

, 3

1

-1

, 0

.

— PANDN

1

AND

1

3

1

.

pcmpgtb  xmm3, xmmword ptr Xmm_30
pandn    xmm1, xmm3

1

1

9

,

, -1

0

.

4.3.1.4. .

— 0

HASH_STR

.

— 1

N_Z_CHAR

pmovmskb HASH_STR, xmm0
pmovmskb N_Z_CHAR, xmm1

16 HASH_STR

16 , 1

0

, 16 N_Z_CHAR

16 , , 1

0

.

4.3.2. .

movdqu   xmm0,[CUR_CHAR]
movdqa   xmm2, xmm0
movdqa   xmm3, xmm0
pcmpgtb  xmm0, xmmword ptr Xmm_39
movdqa   xmm1, xmm0
pcmpgtb  xmm2, xmmword ptr Xmm_SL
pcmpgtb  xmm3, xmmword ptr Xmm_30
pandn    xmm0, xmm2
pandn    xmm1, xmm3

4.3.3. .

— 0

EAX

.

— 16 HASH_STR

HASH_STR

.

— HASH_STR

EAX

.

— 1

EAX

.

— 16 N_Z_CHAR

N_Z_CHAR

.

— N_Z_CHAR

EAX

.

pmovmskb  eax, xmm0
shl  HASH_STR, xmmword
add  HASH_STR, eax
pmovmskb  eax, xmm1
shl  N_Z_CHAR, xmmword
add  N_Z_CHAR, eax

HASH_STR

1

0

, , N_Z_CHAR

1

, 0

, .

4.4. .

4.4.1. .

— HASH_STR

1, EAX

ZF=1

.

— ZF=1

.

— ZF=0

.

— ZF=0

.

bsf   eax, HASH_STR
jz  ErrorExit
test  eax, eax
jnz ErrorExit

. BSF

, 1

0

BSF

0

ZF=0

, 1

, ZF=1

.

4.4.2. .

— HASH_STR

1

.

— HASH_STR

, DOT_CHAR

ZF=1

HASH_STR

.

— ZF=1

.

—

ZF=0

.

— ZF=0

.

not  HASH_STR
bsf  DOT_CHAR, HASH_STR
jz  ErrorExit
cmp  byte ptr[CUR_CHAR + DOT_CHAR], '.'
jnz ErrorExit

4.4.3. .

— N_Z_CHAR

EAX

— N_Z_CHAR

.

— 0000

1 () BUFF_STR

.

— 0

, N_Z_CHAR

, .

— BUFF_STR

.

— 0

N_Z_CHAR

16 .

—

BUFF_STR

16 .

mov        eax, N_Z_CHAR
bsf   N_Z_CHAR, N_Z_CHAR
mov   dword ptr[BUFF_STR - byte], 30303030h
movdqu    xmm0,[CUR_CHAR + N_Z_CHAR]
movdqu         [BUFF_STR + 00000000], xmm0
movdqu    xmm0,[CUR_CHAR + N_Z_CHAR + xmmword]
movdqu         [BUFF_STR + 00000000 + xmmword], xmm0

32

N_Z_CHAR

BUFF_STR

. .

4.5. .

4.5.1. .

— , , DOT_CHAR

0

.

— , , DOT_CHAR

16 1

.

movdqu  xmm0,[CUR_CHAR + DOT_CHAR + byte]
movdqu  xmm1,[CUR_CHAR + DOT_CHAR + byte + xmmword]

4.5.2. .

— HASH_STR

DOT_CHAR

, .

— HASH_STR

ZF=1

.

— ZF=1

.

btr    HASH_STR, DOT_CHAR
bsf    END_FRAC, HASH_STR
jz  ErrorExit

EXP_CHAR

.

4.5.3. .

4.5.3.1. .

— END_FRAC

N_Z_CHAR

CF=1

N_Z_CHAR

END_FRAC

.

— END_FRAC

N_Z_CHAR

CF=1

.

cmp    END_FRAC, N_Z_CHAR
cmovc  N_Z_CHAR, END_FRAC

, N_Z_CHAR

END_FRAC

, N_Z_CHAR

END_FRAC

.

4.5.3.2. .

— N_Z_CHAR

DOT_CHAR

N_Z_CHAR

DOT_CHAR

, , , CF=1

.

— LEN_NUMB

END_FRAC

.

— LEN_NUMB

N_Z_CHAR

CF

.

cmp    N_Z_CHAR, DOT_CHAR
mov    LEN_NUMB, END_FRAC
sbb    LEN_NUMB, N_Z_CHAR

LEN_NUMB

, , .

4.5.4. .

— DOT_CHAR

N_Z_CHAR

SF=0

, .

— OFF_CHAR

20

.

— SF=0

DOT_CHAR

OFF_CHAR

.

—

OFF_CHAR

BUFF_STR

.

—

OFF_CHAR

16 , BUFF_STR

sub    DOT_CHAR, N_Z_CHAR
mov    OFF_CHAR, xmmword + dword
cmovns OFF_CHAR, DOT_CHAR
movdqu   xmmword ptr[BUFF_STR + OFF_CHAR + 0000000], xmm0
movdqu   xmmword ptr[BUFF_STR + OFF_CHAR + xmmword], xmm1

OFF_CHAR

, OFF_CHAR

20

. «» , , .

4.5.5. .

— 2

.

—

LEN_NUMB

BUFF_STR

.

—

LEN_NUMB

16 , BUFF_STR

.

— LEN_CELL

DOT_CHAR

.

movdqu     xmm2, xmmword ptr Xmm_30
movdqu           xmmword ptr[BUFF_STR + LEN_NUMB + 0000000], xmm2
movdqu           xmmword ptr[BUFF_STR + LEN_NUMB + xmmword], xmm2
lea    LEN_CELL, [DOT_CHAR * 2]

«» ,

, LEN_NUMB

. , 20

. LEN_CELL

.

4.6. .

4.6.1. .

— N_Z_CHAR

.

— 0

END_FRAC

.

— END_FRAC

0

.

— END_FRAC

0

.

— 0

1

.

xor  N_Z_CHAR, N_Z_CHAR
movd     xmm0, dword ptr[CUR_CHAR + END_FRAC]
pshuflw  xmm0, xmm0, 0
pshufd   xmm0, xmm0, 0
movdqa   xmm1, xmm0

4.6.2. .

— 0

-1

0

.

— 1

-1

0

.

— 0

1

0

.

— 1

1

-1

.

— PTEST

AND

0

1

-1

ZF=0

.

— ZF=0 .

pcmpeqw  xmm0, Mask_001
pcmpeqw  xmm1, Mask_010
paddw    xmm0, xmm1
pcmpeqb  xmm1, xmm1
ptest    xmm0, xmm1
jnz @f

4.6.3. .

— EDX

END_FRAC

.

— ZF=1

EDX

0

.

—

ZF=1[/INLINE                  .
      

        
        
        
      

    

      

        
        
        
      

    

movzx     edx, word ptr[CUR_CHAR + END_FRAC]
test       dl, dl
jz  @f

4.7. .

4.7.1. .

— 5

EDX

.

— ZF=0

EDX

.

— ZF=0

.

btr       edx, 5
cmp        dl,'E'
jnz ErrorExit

4.7.2.

4.7.2.1. .

— HASH_STR

EXP_CHAR

,

.

— EXP_CHAR

1

.

— HASH_STR

EXP_CHAR

,

/

CF=1

0

.

— CF=1

EDX

Plus

.

— EXP_CHAR

CF=1

.

btr    HASH_STR, EXP_CHAR
inc    EXP_CHAR
btr    HASH_STR, EXP_CHAR
cmovnc  dx, Plus
adc    EXP_CHAR, 0

. .

4.7.2.2. .

— ZF=1

DH

.

— DL

1

ZF=1

.

— ZF=1

DH

.

— DH

1

ZF=1

.

— 8

DX

CF

.

— LEN_CELL

CF

.

— ZF=1

EDX

0

.

—

cmp     dh,'+'
setz    dl
cmp     dh,'-'
setz    dh
bt      dx, 8
adc    LEN_CELL, 0

LEN_CELL

, LEN_CELL

.

4.7.3. .

— EAX

N_Z_CHAR

N_Z_CHAR

EAX

4.4.3.

— EAX

.

— EAX

EXP_CHAR

.

— EAX

, , -1

EAX

EXP_CHAR

1

0

.

— EAX

1

.

—

mov  N_Z_CHAR, eax
xor       eax, eax
bts       eax, EXP_CHAR
add       eax, -1
not       eax
and  N_Z_CHAR, eax
bsf  N_Z_CHAR, N_Z_CHAR
movdqu   xmm0,[CUR_CHAR + N_Z_CHAR]

4.7.4. .

bsf  END_CHAR, END_CHAR
jz  ErrorExit 
movzx     eax, byte ptr[CUR_CHAR + END_CHAR]
cmp       eax, 20h
ja  ErrorExit
add       rdx,(1 + 1 shl 09h + 1 shl 0Dh + 1 shl 20h)
bt        rdx, rax
jnc ErrorExit

4.8. - -

	sub  N_Z_CHAR, END_CHAR
	cmp  N_Z_CHAR, -4
;	jnc ErrorExit
@@:	cmp    byte ptr[BUFF_STR + 00000000 + xmmword + dword - byte],'5'
	mov   dword ptr[BUFF_STR + 00000000 + xmmword + dword - byte],'0000'
	movd  dword ptr[BUFF_STR + N_Z_CHAR + xmmword + qword - byte], xmm0

4.9.

	;       #region
		movdqu    xmm0,[BUFF_STR + 0000000 - byte]
		movdqu    xmm1,[BUFF_STR + xmmword - byte]
		psubb     xmm0, xmm2
		psubb     xmm1, xmm2
		pmaddubsw xmm1, xmmword ptr Xmm_0001
		pmaddwd   xmm1, xmmword ptr Xmm_0010
	; #endregion

4.10.

	;   #region
		movd      rax, xmm1
		sbb       rax, -1
		movd     xmm1, eax
		shr       rax, 20h
		movd     xmm2, rbx
		mov       ebx, eax
		neg       eax
		sar  LEN_CELL, 1
		cmovc     ebx, eax
		add       ebx, LEN_CELL
		mov       eax, ebx
		neg       eax
		cmovns    ebx, eax

		mov         rax, 0A000000000000000h
		mov    MANT_ARG, 0CCCCCCCCCCCCCCCCh
		cmovs  MANT_ARG, rax
		mov         eax, 3
		mov    LOGB_ARG, -3
		cmovs  LOGB_ARG, eax

		mov    MANT_MUL, 1
		mov    LOGB_MUL, 0
		shr    HASH_MUL, 1 
		cmovc  MANT_MUL, MANT_ARG
		cmovc  LOGB_MUL, LOGB_ARG
	
	@@:	jz  @f
		mov         rax, MANT_ARG
		mul         rax
		bt          rdx, 3Fh
		setnc        cl
		adc    LOGB_ARG, LOGB_ARG
		shld        rdx, rax, cl
		mov    MANT_ARG, rdx
		shr    HASH_MUL, 1
	jnc @b	

		mov         rax, rdx
		mul    MANT_MUL
		bt          rdx, 3Fh
		setnc        cl
		adc    LOGB_MUL, LOGB_ARG
		shld        rdx, rax, cl
		mov    MANT_MUL, rdx
		test   HASH_MUL, HASH_MUL
	jmp @b

	@@:	movd   rbx, xmm2
	; #endregion

4.11. .

	;     #region
		psubb     xmm0, xmm2
		pmaddubsw xmm0, xmmword ptr Xmm_0001
		pmaddwd   xmm0, xmmword ptr Xmm_0010
		pmulld    xmm0, xmmword ptr Xmm_0100
		phaddd    xmm0, xmm0

		movd       eax, xmm0
		imul       rax, Mul_0001
		pextrd     edx, xmm0, 1
		imul       rdx, 02710h
		add        rax, rdx
		movd       edx, xmm1
		add        rax, rdx
		bsr        rcx, rax
		add   LOGB_MUL, ecx
		inc         cl
		shrd       rax, rax, cl
	; #endregion

4.12. .

	;   #region
		mul   MANT_MUL
		bt         rdx, 3Fh
		setnc       cl
		adc   LOGB_MUL, 3FFh
		shld       rdx, rax, cl
		shl        rdx, 1
		shrd       rdx, r11, 11
		shrd       rdx, rsp, 1
		btr        esp, 0
		movd      xmm0, rdx
	; #endregion

4.13. .

ret

4.14. ErrorExit

	ErrorExit:	;   #region
		mov      ecx, -1
		pcmpeqb xmm1, xmm1
		psllq   xmm1, 52 + 1
		psrlq   xmm1, 1
		ret
	; #endregion

Convertir una cadena de caracteres en un doble

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