mirror of https://github.com/dirtbags/moth.git
56 lines
1.6 KiB
C
56 lines
1.6 KiB
C
/*
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------------------------------------------------------------------------------
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rand.h: definitions for a random number generator
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By Bob Jenkins, 1996, Public Domain
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MODIFIED:
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960327: Creation (addition of randinit, really)
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970719: use context, not global variables, for internal state
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980324: renamed seed to flag
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980605: recommend RANDSIZL=4 for noncryptography.
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010626: note this is public domain
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101005: update to C99 (neale@lanl.gov)
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------------------------------------------------------------------------------
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*/
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#ifndef __ISAAC_H__
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#define __ISAAC_H__
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#include <stdint.h>
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#define RANDSIZL (8)
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#define RANDSIZ (1<<RANDSIZL)
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/* context of random number generator */
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struct randctx {
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uint32_t randcnt;
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uint32_t randrsl[RANDSIZ];
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uint32_t randmem[RANDSIZ];
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uint32_t randa;
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uint32_t randb;
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uint32_t randc;
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};
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/*
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------------------------------------------------------------------------------
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If (flag==TRUE), then use the contents of randrsl[0..RANDSIZ-1] as the seed.
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------------------------------------------------------------------------------
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*/
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void randinit(struct randctx *ctx, uint_fast8_t flag);
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void isaac(struct randctx *ctx);
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/*
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------------------------------------------------------------------------------
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Call rand(/o_ randctx *r _o/) to retrieve a single 32-bit random value
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------------------------------------------------------------------------------
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*/
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#define rand32(r) \
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(!(r)->randcnt-- ? \
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(isaac(r), (r)->randcnt=RANDSIZ-1, (r)->randrsl[(r)->randcnt]) : \
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(r)->randrsl[(r)->randcnt])
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#endif /* RAND */
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#endif /* __ISAAC_H__ */
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