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Diffstat (limited to 'src/systemc/tests/systemc/datatypes/int/arith/arith05/isaac.h')
| -rw-r--r-- | src/systemc/tests/systemc/datatypes/int/arith/arith05/isaac.h | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/src/systemc/tests/systemc/datatypes/int/arith/arith05/isaac.h b/src/systemc/tests/systemc/datatypes/int/arith/arith05/isaac.h new file mode 100644 index 000000000..9625be2ac --- /dev/null +++ b/src/systemc/tests/systemc/datatypes/int/arith/arith05/isaac.h @@ -0,0 +1,272 @@ +#ifndef __ISAAC_HPP +#define __ISAAC_HPP + + +/* + + C++ TEMPLATE VERSION OF Robert J. Jenkins Jr.'s + ISAAC Random Number Generator. + + Ported from vanilla C to to template C++ class + by Quinn Tyler Jackson on 16-23 July 1998. + + quinn@qtj.net + + The function for the expected period of this + random number generator, according to Jenkins is: + + f(a,b) = 2**((a+b*(3+2^^a)-1) + + (where a is ALPHA and b is bitwidth) + + So, for a bitwidth of 32 and an ALPHA of 8, + the expected period of ISAAC is: + + 2^^(8+32*(3+2^^8)-1) = 2^^8295 + + Jackson has been able to run implementations + with an ALPHA as high as 16, or + + 2^^2097263 + +*/ + + +typedef unsigned int UINT32; +const UINT32 GOLDEN_RATIO = UINT32(0x9e3779b9); + + +template <UINT32 ALPHA = (8)> +class QTIsaac +{ + public: + + typedef unsigned char byte; + + struct randctx + { + randctx(void) + { + randrsl = new UINT32[N]; + randmem = new UINT32[N]; + } + + ~randctx(void) + { + delete [] randrsl; + delete [] randmem; + } + + UINT32 randcnt; + UINT32* randrsl; + UINT32* randmem; + UINT32 randa; + UINT32 randb; + UINT32 randc; + }; + + QTIsaac(UINT32 a = 0, UINT32 b = 0, UINT32 c = 0); + virtual ~QTIsaac(void); + + UINT32 rand(void); + virtual void randinit(randctx* ctx, bool bUseSeed); + virtual void srand( + UINT32 a = 0, UINT32 b = 0, UINT32 c = 0, UINT32* s = NULL); + + enum {N = (1<<ALPHA)}; + + protected: + + virtual void isaac(randctx* ctx); + + UINT32 ind(UINT32* mm, UINT32 x); + void rngstep( + UINT32 mix, UINT32& a, UINT32& b, UINT32*& mm, UINT32*& m, + UINT32*& m2, UINT32*& r, UINT32& x, UINT32& y); + virtual void shuffle( + UINT32& a, UINT32& b, UINT32& c, UINT32& d, UINT32& e, UINT32& f, + UINT32& g, UINT32& h); + + private: + randctx m_rc; +}; + + +template<UINT32 ALPHA> +QTIsaac<ALPHA>::QTIsaac(UINT32 a, UINT32 b, UINT32 c) : m_rc() +{ + srand(a, b, c); +} + + +template<UINT32 ALPHA> +QTIsaac<ALPHA>::~QTIsaac(void) +{ + // DO NOTHING +} + + +template<UINT32 ALPHA> +void QTIsaac<ALPHA>::srand(UINT32 a, UINT32 b, UINT32 c, UINT32* s) +{ + for(int i = 0; i < N; i++) + { + m_rc.randrsl[i] = s != NULL ? s[i] : 0; + } + + m_rc.randa = a; + m_rc.randb = b; + m_rc.randc = c; + + randinit(&m_rc, true); +} + + +template<UINT32 ALPHA> +inline UINT32 QTIsaac<ALPHA>::rand(void) +{ + return 0x7fffffff & (!m_rc.randcnt-- ? + (isaac(&m_rc), m_rc.randcnt=(N-1), m_rc.randrsl[m_rc.randcnt]) : + m_rc.randrsl[m_rc.randcnt]); +} + + +template<UINT32 ALPHA> +inline void QTIsaac<ALPHA>::randinit(randctx* ctx, bool bUseSeed) +{ + UINT32 a,b,c,d,e,f,g,h; + int i; + + a = b = c = d = e = f = g = h = GOLDEN_RATIO; + + UINT32* m = (ctx->randmem); + UINT32* r = (ctx->randrsl); + + if(!bUseSeed) + { + ctx->randa = 0; + ctx->randb = 0; + ctx->randc = 0; + } + + // scramble it + for(i=0; i < 4; ++i) + { + shuffle(a,b,c,d,e,f,g,h); + } + + if(bUseSeed) + { + // initialize using the contents of r[] as the seed + + for(i=0; i < N; i+=8) + { + a+=r[i ]; b+=r[i+1]; c+=r[i+2]; d+=r[i+3]; + e+=r[i+4]; f+=r[i+5]; g+=r[i+6]; h+=r[i+7]; + + shuffle(a,b,c,d,e,f,g,h); + + m[i ]=a; m[i+1]=b; m[i+2]=c; m[i+3]=d; + m[i+4]=e; m[i+5]=f; m[i+6]=g; m[i+7]=h; + } + + //do a second pass to make all of the seed affect all of m + + for(i=0; i < N; i += 8) + { + a+=m[i ]; b+=m[i+1]; c+=m[i+2]; d+=m[i+3]; + e+=m[i+4]; f+=m[i+5]; g+=m[i+6]; h+=m[i+7]; + + shuffle(a,b,c,d,e,f,g,h); + + m[i ]=a; m[i+1]=b; m[i+2]=c; m[i+3]=d; + m[i+4]=e; m[i+5]=f; m[i+6]=g; m[i+7]=h; + } + } + else + { + // fill in mm[] with messy stuff + + shuffle(a,b,c,d,e,f,g,h); + + m[i ]=a; m[i+1]=b; m[i+2]=c; m[i+3]=d; + m[i+4]=e; m[i+5]=f; m[i+6]=g; m[i+7]=h; + + } + + isaac(ctx); // fill in the first set of results + ctx->randcnt = N; // prepare to use the first set of results +} + + +template<UINT32 ALPHA> +inline UINT32 QTIsaac<ALPHA>::ind(UINT32* mm, UINT32 x) +{ + return (*(UINT32*)((byte*)(mm) + ((x) & ((N-1)<<2)))); +} + + +template<UINT32 ALPHA> +inline void QTIsaac<ALPHA>::rngstep(UINT32 mix, UINT32& a, UINT32& b, UINT32*& mm, UINT32*& m, UINT32*& m2, UINT32*& r, UINT32& x, UINT32& y) +{ + x = *m; + a = (a^(mix)) + *(m2++); + *(m++) = y = ind(mm,x) + a + b; + *(r++) = b = ind(mm,y>>ALPHA) + x; +} + + +template<UINT32 ALPHA> +inline void QTIsaac<ALPHA>::shuffle(UINT32& a, UINT32& b, UINT32& c, UINT32& d, UINT32& e, UINT32& f, UINT32& g, UINT32& h) +{ + a^=b<<11; d+=a; b+=c; + b^=c>>2; e+=b; c+=d; + c^=d<<8; f+=c; d+=e; + d^=e>>16; g+=d; e+=f; + e^=f<<10; h+=e; f+=g; + f^=g>>4; a+=f; g+=h; + g^=h<<8; b+=g; h+=a; + h^=a>>9; c+=h; a+=b; +} + + +template<UINT32 ALPHA> +inline void QTIsaac<ALPHA>::isaac(randctx* ctx) +{ + UINT32 x,y; + + UINT32* mm = ctx->randmem; + UINT32* r = ctx->randrsl; + + UINT32 a = (ctx->randa); + UINT32 b = (ctx->randb + (++ctx->randc)); + + UINT32* m = mm; + UINT32* m2 = (m+(N/2)); + UINT32* mend = m2; + + for(; m<mend; ) + { + rngstep((a<<13), a, b, mm, m, m2, r, x, y); + rngstep((a>>6) , a, b, mm, m, m2, r, x, y); + rngstep((a<<2) , a, b, mm, m, m2, r, x, y); + rngstep((a>>16), a, b, mm, m, m2, r, x, y); + } + + m2 = mm; + + for(; m2<mend; ) + { + rngstep((a<<13), a, b, mm, m, m2, r, x, y); + rngstep((a>>6) , a, b, mm, m, m2, r, x, y); + rngstep((a<<2) , a, b, mm, m, m2, r, x, y); + rngstep((a>>16), a, b, mm, m, m2, r, x, y); + } + + ctx->randb = b; + ctx->randa = a; +} + + +#endif // __ISAAC_HPP + |