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flat assembler > Macroinstructions > Random number macro

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omega_red



Joined: 13 Mar 2004
Posts: 19
Location: Poland
I want to create a macro that would return a pseudorandom number. I've adapted simple PRNG:
Code:
random_seed = 1

macro random
{
       random_seed = (random_seed*214013+2531011) shr 16
   dd      random_seed
}    

However, this code eventually gives me an error: value out of range. How to make it to truncate value without giving the error?

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Post 03 Oct 2004, 16:05
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decard



Joined: 11 Sep 2003
Posts: 1095
Location: Poland
try this:
Code:
random_seed = ((random_seed*214013+2531011) shr 16) and 0xffffffff    


you can use %t as an initial value of random_seed
Post 03 Oct 2004, 18:34
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omega_red



Joined: 13 Mar 2004
Posts: 19
Location: Poland
Thanks, that's working.
Post 03 Oct 2004, 19:13
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Matrix



Joined: 04 Sep 2004
Posts: 1171
Location: Overflow
i have made my latest randomz3 routine a macro version Smile

Code:
__lasttimevar=0
__random_seed = %t
__range=$ffffffff

macro db_4random_bytes
{
;randomz3: ; Z3 ecx=range transparent
__timevar=%t
__random_seed=(__random_seed+__timevar)and 0xffffffff

__al=(__timevar and $ff) xor ((__timevar shr 8) and $ff)

__ch_1=(__range shr 8) and $ff
;ror ch,4
__ch_tmp1=(__ch_1 shr 4) and $f
__ch_tmp2=(__ch_1 and $f) shl 4
__ch=__ch_tmp1 or __ch_tmp2

;xor bl,ch
__bl_1=__random_seed and $ff
__bl=__bl_1 xor __ch_1

cl_and_f=__range and $f
__bx_1=__random_seed and $ffff
;rol bx,cl
__bx_tmp1=(__bx_1 shl cl_and_f)
__bx_tmp2=(__bx_tmp1 shr 16)
__bx_tmp1=__bx_tmp1 and $ffff
__bx=__bx_tmp1 or __bx_tmp2

;btc bx,cx
__bx=__bx xor (1 shl cl_and_f)
__bx=__bx xor ((__timevar and $ff)xor((__timevar shr 16) and $ff))

;mov cl,al xor cl,ah
__al=(__timevar and $ff) xor ((__timevar shr 8) and $ff)

;ror ch,4
__ch_tmp1=(__ch_1 shr 4) and $f
__ch_tmp2=(__ch_1 and $f) shl 4
__ch=__ch_tmp1 or __ch_tmp2
;xor bl,ch
__bl=__bl_1 xor __ch_1

;ror bx,cl
__bx_tmp1=__bx_1 shl 16
__bx_tmp2=(__bx_tmp1 shr cl_and_f) and $ffff
__bx_tmp1=__bx_tmp2 shr 16
__bx=__bx_tmp1 or __bx_tmp2

;btc bx,cx
__bx=__bx xor (1 shl cl_and_f)

__bx=__bx xor ((__timevar and $ff)xor((__timevar shr 16) and $ff))

__cl=__bx and $ff

repeat __cl
;rol eax,cl
__timevar_tmp1=(__timevar shl __cl) and $ffffffff
__timevar_tmp2=(__timevar shr (32-__cl)) and $ffffffff
__timevar=__timevar_tmp1 or __timevar_tmp2
__cl=__cl and $f
;btc ax,cx
__timevar=__timevar xor (1 shl __cl)
end repeat

__cl=(__bx shr 8) and $ff
repeat __cl
;ror eax,cl
__timevar_tmp1=(__timevar shl (32-__cl)) and $ffffffff
__timevar_tmp2=(__timevar shr __cl)
__timevar=__timevar_tmp1 or __timevar_tmp2
__cl=__cl and $f
;btc ax,cx
__timevar=__timevar xor (1 shl __cl)
end repeat

__timevar=__timevar mod __range

dd __timevar and $ffffffff
}

db_4random_bytes
db_4random_bytes
db_4random_bytes
    
Post 09 Nov 2004, 15:07
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Matrix



Joined: 04 Sep 2004
Posts: 1171
Location: Overflow
Sad i have made it cleaned up, and i can't mke it work on multiple bytes, cause %t is not rdtsc, ccan't get current timstamp while compiling.

Code:
__lasttimevar=0
__random_seed = %t
;__range=$ffffffff
__range=1

macro db_4random_bytes ;randomz3 __range=range __random_seed= random seed
{
__timevar=%t
__random_seed=__random_seed + %t and 0xffffffff

__al=(__timevar and $ff) xor ((__timevar shr 8) and $ff)

__ch_1=(__range shr 8) and $ff
;ror ch,4
__ch_tmp1=(__ch_1 shr 4) and $f
__ch_tmp2=(__ch_1 and $f) shl 4
__ch=__ch_tmp1 or __ch_tmp2

;xor bl,ch
__bl_1=__random_seed and $ff
__bl=__bl_1 xor __ch_1

cl_and_f=__range and $f
__bx_1=__random_seed and $ffff
;rol bx,cl
__bx_tmp1=(__bx_1 shl cl_and_f)
__bx_tmp2=(__bx_tmp1 shr 16)
__bx_tmp1=__bx_tmp1 and $ffff
__bx=__bx_tmp1 or __bx_tmp2

;btc bx,cx
__bx=__bx xor (1 shl cl_and_f)
__bx=__bx xor ((__timevar and $ff)xor((__timevar shr 16) and $ff))

;mov cl,al xor cl,ah
__al=(__timevar and $ff) xor ((__timevar shr 8) and $ff)

;ror ch,4
__ch_tmp1=(__ch_1 shr 4) and $f
__ch_tmp2=(__ch_1 and $f) shl 4
__ch=__ch_tmp1 or __ch_tmp2
;xor bl,ch
__bl=__bl_1 xor __ch_1

;ror bx,cl
__bx_tmp1=__bx_1 shl 16
__bx_tmp2=(__bx_tmp1 shr cl_and_f) and $ffff
__bx_tmp1=__bx_tmp2 shr 16
__bx=__bx_tmp1 or __bx_tmp2

;btc bx,cx
__bx=__bx xor (1 shl cl_and_f)

__bx=__bx xor ((__timevar and $ff)xor((__timevar shr 16) and $ff))

__cl=__bx and $ff

repeat __cl
;rol eax,cl
__timevar_tmp1=(__timevar shl __cl) and $ffffffff
__timevar_tmp2=(__timevar shr (32-__cl)) and $ffffffff
__timevar=__timevar_tmp1 or __timevar_tmp2
__cl=__cl and $f
;btc ax,cx
__timevar=__timevar xor (1 shl __cl)
end repeat

__cl=(__bx shr 8) and $ff
repeat __cl
;ror eax,cl
__timevar_tmp1=(__timevar shl (32-__cl)) and $ffffffff
__timevar_tmp2=(__timevar shr __cl)
__timevar=__timevar_tmp1 or __timevar_tmp2
__cl=__cl and $f
;btc ax,cx
__timevar=__timevar xor (1 shl __cl)
end repeat

__timevar=__timevar mod __range

dd __timevar and $ffffffff

}

repeat 120
db_4random_bytes
end repeat
    
Post 09 Nov 2004, 16:09
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