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Roman



Joined: 21 Apr 2012
Posts: 1701
Roman 08 Jan 2024, 09:41
Fasmw 1.73
How do this in three commands?
Code:
Cmp Al, "0"
Jb @f
Cmp Al, "9"
Ja @f
Do some code
@@:

    
Post 08 Jan 2024, 09:41
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revolution
When all else fails, read the source


Joined: 24 Aug 2004
Posts: 20121
Location: In your JS exploiting you and your system
revolution 08 Jan 2024, 10:10
Code:
sub al,'0'
cmp al,9
ja .out_of_range
; do my thing
.out_of_range:    
Post 08 Jan 2024, 10:10
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MatQuasar



Joined: 25 Oct 2023
Posts: 99
MatQuasar 08 Jan 2024, 10:33
Try:

Code:
  mov    eax, "1"
  xor    al, 0x30
  cmp    al, 9
  ja     quit       
Post 08 Jan 2024, 10:33
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Roman



Joined: 21 Apr 2012
Posts: 1701
Roman 08 Jan 2024, 10:39
Thanks.
Both variants work fine.
I tested.
Post 08 Jan 2024, 10:39
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revolution
When all else fails, read the source


Joined: 24 Aug 2004
Posts: 20121
Location: In your JS exploiting you and your system
revolution 08 Jan 2024, 11:02
It is a generic range inclusion test.
Code:
range_begin     =  '0'
range_end       =  '9'

        sub     al,range_begin
        cmp     al,range_end - range_begin
        ja      .out_of_range
        ; do the thing
    .out_of_range:    
And it also works for negative ranges (an exclusion test) that wraps around from the beginning to the end
Code:
range_begin     =  '9'
range_end       =  '0'

        sub     al,range_begin
        cmp     al,range_end - range_begin
        ja      .out_of_range
        ; do the thing
    .out_of_range:    
Post 08 Jan 2024, 11:02
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Picnic



Joined: 05 May 2007
Posts: 1386
Location: Piraeus, Greece
Picnic 09 Jan 2024, 12:10
How about:
Code:

    lea ecx, [eax-'0']
    cmp ecx, 10
    jc _isdigit
    

_________________
Hobby BASIC Interpreter
Post 09 Jan 2024, 12:10
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revolution
When all else fails, read the source


Joined: 24 Aug 2004
Posts: 20121
Location: In your JS exploiting you and your system
revolution 09 Jan 2024, 14:31
Using the full eax value might be a problem if the top 24 bits are not well defined. But you can change it to this:
Code:
    lea ecx, [eax-'0']
    cmp cl, 10
    jc _isdigit    
Post 09 Jan 2024, 14:31
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Roman



Joined: 21 Apr 2012
Posts: 1701
Roman 09 Jan 2024, 14:57
lea ecx, [eax-'0'] not faster than sub AL,"0"
And sub AL,"0" less bytes

lea ecx, [eax-'0'] 3 bytes

sub AL,"0" 2 bytes
Post 09 Jan 2024, 14:57
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