| 0,0 → 1,127 |
|---|
| ; ----------------------------- MOTHER.ASM ----------------------------- |
| ; Mother-of-All random number generator by Agner Fog 1998 |
| ; 32-bit mode version for 80x86 and compatible microprocessors |
| ; |
| ; MRandom returns a floating point number between 0 and 1. |
| ; MRandomInit must be called before the first call to MRandom. |
| ; |
| ; C++ prototypes: |
| ; extern "C" void MRandomInit (int seed); |
| ; extern "C" double MRandom (void); |
| ; extern "C" int MIRandom (int min, int max); |
| ; |
| ; © 1998, 2004 Agner Fog. |
| ; GNU General Public License www.gnu.org/copyleft/gpl.html |
| ; ---------------------------------------------------------------------- |
| |
| ; The MRandom function is optimized for the Pentium microprocessor. |
| |
| iglobal |
| mf3 dd 2111111111 ; factors |
| mf2 dd 1492 |
| mf1 dd 1776 |
| mf0 dd 5115 |
| endg |
| |
| |
| uglobal |
| m0 dd ? ; history buffer |
| m1 dd ? |
| m2 dd ? |
| m3 dd ? |
| mc dd ? |
| temprng dq ? ; used for conversion to float |
| endg |
| |
| |
| proc init_random |
| |
| mcall 26, 10 ; seed |
| xor ecx, ecx |
| ; make random numbers and put them into buffer |
| @@: |
| imul eax, 29943829 |
| dec eax |
| mov [m0+ecx*4], eax |
| inc ecx |
| cmp ecx, 5 |
| jb @r |
| push edi |
| mov edi, 19 |
| @@: |
| call MRandom |
| fstp st0 |
| dec edi |
| jnz @r |
| pop edi |
| ret |
| |
| endp |
| |
| |
| proc MRandom |
| |
| call MBRandom ; random bits |
| mov edx, eax ; fast conversion to float |
| shr eax, 12 |
| or eax, 3ff00000h |
| shl edx, 20 |
| mov dword[temprng+4], eax |
| mov dword[temprng], edx |
| fld1 |
| fld [temprng] ; partial memory stall here |
| fsubr st0, st1 |
| ret |
| |
| endp |
| |
| |
| proc MIRandom, max, min ; make random integer in desired interval |
| |
| call MBRandom ; make random number |
| mov edx, [max] |
| mov ecx, [min] |
| sub edx, ecx |
| js .error ; max < min |
| inc edx ; max - min + 1 |
| mul edx ; multiply random number by interval and truncate |
| lea eax, [edx+ecx] ; add min |
| ret |
| |
| .error: |
| mov eax, 80000000h ; error exit |
| ret |
| |
| endp |
| |
| |
| proc MBRandom |
| |
| push edi |
| mov eax, [mf3] |
| mul [m3] ; x[n-4] |
| mov ecx, eax |
| mov eax, [m2] ; x[n-3] |
| mov edi, edx |
| mov [m3], eax |
| mul [mf2] |
| add ecx, eax |
| mov eax, [m1] ; x[n-2] |
| adc edi, edx |
| mov [m2], eax |
| mul [mf1] |
| add ecx, eax |
| mov eax, [m0] ; x[n-1] |
| adc edi, edx |
| mov [m1], eax |
| mul [mf0] |
| add eax, ecx |
| adc edx, edi |
| add eax, [mc] |
| adc edx, 0 |
| mov [m0], eax |
| mov [mc], edx |
| pop edi |
| ret |
| |
| endp |