-/*Written by Timothy B. Terriberry (tterribe@xiph.org) 1999-2009 public domain.
+/*Written by Timothy B. Terriberry (tterribe@xiph.org) 1999-2009
+ CC0 (Public domain) - see LICENSE file for details
Based on the public domain ISAAC implementation by Robert J. Jenkins Jr.*/
#include <float.h>
#include <math.h>
#include <string.h>
#include <ccan/ilog/ilog.h>
#include "isaac64.h"
-#if defined(__GNUC_PREREQ)
-# if __GNUC_PREREQ(4,2)
-# pragma GCC diagnostic ignored "-Wparentheses"
-# endif
-#endif
-
#define ISAAC64_MASK ((uint64_t)0xFFFFFFFFFFFFFFFFULL)
+/* Extract ISAAC64_SZ_LOG bits (starting at bit 3). */
+static inline uint32_t lower_bits(uint64_t x)
+{
+ return (x & ((ISAAC64_SZ-1) << 3)) >>3;
+}
+/* Extract next ISAAC64_SZ_LOG bits (starting at bit ISAAC64_SZ_LOG+2). */
+static inline uint32_t upper_bits(uint32_t y)
+{
+ return (y >> (ISAAC64_SZ_LOG+3)) & (ISAAC64_SZ-1);
+}
static void isaac64_update(isaac64_ctx *_ctx){
uint64_t *m;
m=_ctx->m;
r=_ctx->r;
a=_ctx->a;
- b=_ctx->b+(++_ctx->c)&ISAAC64_MASK;
+ b=_ctx->b+(++_ctx->c);
for(i=0;i<ISAAC64_SZ/2;i++){
x=m[i];
- a=~(a^a<<21)+m[i+ISAAC64_SZ/2]&ISAAC64_MASK;
- m[i]=y=m[(x&ISAAC64_SZ-1<<3)>>3]+a+b&ISAAC64_MASK;
- r[i]=b=m[y>>ISAAC64_SZ_LOG+3&ISAAC64_SZ-1]+x&ISAAC64_MASK;
+ a=~(a^a<<21)+m[i+ISAAC64_SZ/2];
+ m[i]=y=m[lower_bits(x)]+a+b;
+ r[i]=b=m[upper_bits(y)]+x;
x=m[++i];
- a=(a^a>>5)+m[i+ISAAC64_SZ/2]&ISAAC64_MASK;
- m[i]=y=m[(x&ISAAC64_SZ-1<<3)>>3]+a+b&ISAAC64_MASK;
- r[i]=b=m[y>>ISAAC64_SZ_LOG+3&ISAAC64_SZ-1]+x&ISAAC64_MASK;
+ a=(a^a>>5)+m[i+ISAAC64_SZ/2];
+ m[i]=y=m[lower_bits(x)]+a+b;
+ r[i]=b=m[upper_bits(y)]+x;
x=m[++i];
- a=(a^a<<12)+m[i+ISAAC64_SZ/2]&ISAAC64_MASK;
- m[i]=y=m[(x&ISAAC64_SZ-1<<3)>>3]+a+b&ISAAC64_MASK;
- r[i]=b=m[y>>ISAAC64_SZ_LOG+3&ISAAC64_SZ-1]+x&ISAAC64_MASK;
+ a=(a^a<<12)+m[i+ISAAC64_SZ/2];
+ m[i]=y=m[lower_bits(x)]+a+b;
+ r[i]=b=m[upper_bits(y)]+x;
x=m[++i];
- a=(a^a>>33)+m[i+ISAAC64_SZ/2]&ISAAC64_MASK;
- m[i]=y=m[(x&ISAAC64_SZ-1<<3)>>3]+a+b&ISAAC64_MASK;
- r[i]=b=m[y>>ISAAC64_SZ_LOG+3&ISAAC64_SZ-1]+x&ISAAC64_MASK;
+ a=(a^a>>33)+m[i+ISAAC64_SZ/2];
+ m[i]=y=m[lower_bits(x)]+a+b;
+ r[i]=b=m[upper_bits(y)]+x;
}
for(i=ISAAC64_SZ/2;i<ISAAC64_SZ;i++){
x=m[i];
- a=~(a^a<<21)+m[i-ISAAC64_SZ/2]&ISAAC64_MASK;
- m[i]=y=m[(x&ISAAC64_SZ-1<<3)>>3]+a+b&ISAAC64_MASK;
- r[i]=b=m[y>>ISAAC64_SZ_LOG+3&ISAAC64_SZ-1]+x&ISAAC64_MASK;
+ a=~(a^a<<21)+m[i-ISAAC64_SZ/2];
+ m[i]=y=m[lower_bits(x)]+a+b;
+ r[i]=b=m[upper_bits(y)]+x;
x=m[++i];
- a=(a^a>>5)+m[i-ISAAC64_SZ/2]&ISAAC64_MASK;
- m[i]=y=m[(x&ISAAC64_SZ-1<<3)>>3]+a+b&ISAAC64_MASK;
- r[i]=b=m[y>>ISAAC64_SZ_LOG+3&ISAAC64_SZ-1]+x&ISAAC64_MASK;
+ a=(a^a>>5)+m[i-ISAAC64_SZ/2];
+ m[i]=y=m[lower_bits(x)]+a+b;
+ r[i]=b=m[upper_bits(y)]+x;
x=m[++i];
- a=(a^a<<12)+m[i-ISAAC64_SZ/2]&ISAAC64_MASK;
- m[i]=y=m[(x&ISAAC64_SZ-1<<3)>>3]+a+b&ISAAC64_MASK;
- r[i]=b=m[y>>ISAAC64_SZ_LOG+3&ISAAC64_SZ-1]+x&ISAAC64_MASK;
+ a=(a^a<<12)+m[i-ISAAC64_SZ/2];
+ m[i]=y=m[lower_bits(x)]+a+b;
+ r[i]=b=m[upper_bits(y)]+x;
x=m[++i];
- a=(a^a>>33)+m[i-ISAAC64_SZ/2]&ISAAC64_MASK;
- m[i]=y=m[(x&ISAAC64_SZ-1<<3)>>3]+a+b&ISAAC64_MASK;
- r[i]=b=m[y>>ISAAC64_SZ_LOG+3&ISAAC64_SZ-1]+x&ISAAC64_MASK;
+ a=(a^a>>33)+m[i-ISAAC64_SZ/2];
+ m[i]=y=m[lower_bits(x)]+a+b;
+ r[i]=b=m[upper_bits(y)]+x;
}
_ctx->b=b;
_ctx->a=a;
static const unsigned char SHIFT[8]={9,9,23,15,14,20,17,14};
int i;
for(i=0;i<8;i++){
- _x[i]-=_x[i+4&7];
- _x[i+5&7]^=_x[i+7&7]>>SHIFT[i];
- _x[i+7&7]+=_x[i];
+ _x[i]-=_x[(i+4)&7];
+ _x[(i+5)&7]^=_x[(i+7)&7]>>SHIFT[i];
+ _x[(i+7)&7]+=_x[i];
i++;
- _x[i]-=_x[i+4&7];
- _x[i+5&7]^=_x[i+7&7]<<SHIFT[i];
- _x[i+7&7]+=_x[i];
+ _x[i]-=_x[(i+4)&7];
+ _x[(i+5)&7]^=_x[(i+7)&7]<<SHIFT[i];
+ _x[(i+7)&7]+=_x[i];
}
}
v=r%_n;
d=r-v;
}
- while((d+_n-1&ISAAC64_MASK)<d);
+ while(((d+_n-1)&ISAAC64_MASK)<d);
return v;
}
_base-=64;
_bits=isaac64_next_uint64(_ctx);
}
- nbits_needed=FLT_MANT_DIG-ILOGNZ_64(_bits);
+ nbits_needed=FLT_MANT_DIG-ilog64_nz(_bits);
#if FLT_MANT_DIG>64
ret=ldexpf((float)_bits,_base);
# if FLT_MANT_DIG>129
nbits_needed-=64;
ret+=ldexpf((float)isaac64_next_uint64(_ctx),_base);
}
- _bits=isaac64_next_uint64(_ctx)>>64-nbits_needed;
+ _bits=isaac64_next_uint64(_ctx)>>(64-nbits_needed);
ret+=ldexpf((float)_bits,_base-nbits_needed);
#else
if(nbits_needed>0){
- _bits=_bits<<nbits_needed|isaac64_next_uint64(_ctx)>>64-nbits_needed;
+ _bits=_bits<<nbits_needed|isaac64_next_uint64(_ctx)>>(64-nbits_needed);
}
# if FLT_MANT_DIG<64
else _bits>>=-nbits_needed;
_base-=64;
_bits=isaac64_next_uint64(_ctx);
}
- nbits_needed=DBL_MANT_DIG-ILOGNZ_64(_bits);
+ nbits_needed=DBL_MANT_DIG-ilog64_nz(_bits);
#if DBL_MANT_DIG>64
ret=ldexp((double)_bits,_base);
# if DBL_MANT_DIG>129
nbits_needed-=64;
ret+=ldexp((double)isaac64_next_uint64(_ctx),_base);
}
- _bits=isaac64_next_uint64(_ctx)>>64-nbits_needed;
+ _bits=isaac64_next_uint64(_ctx)>>(64-nbits_needed);
ret+=ldexp((double)_bits,_base-nbits_needed);
#else
if(nbits_needed>0){
- _bits=_bits<<nbits_needed|isaac64_next_uint64(_ctx)>>64-nbits_needed;
+ _bits=_bits<<nbits_needed|isaac64_next_uint64(_ctx)>>(64-nbits_needed);
}
# if DBL_MANT_DIG<64
else _bits>>=-nbits_needed;