PRNG changed from 'xoroshiro128+' to 'xoshiro256**' + "I' renamed 'Rand64'
+ implementation can use integer types larger than 64 (or 32) bits
diff --git a/lmathlib.c b/lmathlib.c
index 3e5ceea..aa93f4b 100644
--- a/lmathlib.c
+++ b/lmathlib.c
@@ -1,5 +1,5 @@
/*
-** $Id: lmathlib.c,v 1.128 2018/03/26 19:48:46 roberto Exp $
+** $Id: lmathlib.c,v 1.129 2018/04/04 16:12:53 roberto Exp roberto $
** Standard mathematical library
** See Copyright Notice in lua.h
*/
@@ -230,12 +230,8 @@
static int math_type (lua_State *L) {
- if (lua_type(L, 1) == LUA_TNUMBER) {
- if (lua_isinteger(L, 1))
- lua_pushliteral(L, "integer");
- else
- lua_pushliteral(L, "float");
- }
+ if (lua_type(L, 1) == LUA_TNUMBER)
+ lua_pushstring(L, (lua_isinteger(L, 1)) ? "integer" : "float");
else {
luaL_checkany(L, 1);
lua_pushnil(L);
@@ -247,7 +243,7 @@
/*
** {==================================================================
-** Pseudo-Random Number Generator based on 'xoroshiro128+'.
+** Pseudo-Random Number Generator based on 'xoshiro256**'.
** ===================================================================
*/
@@ -261,29 +257,43 @@
#endif
-#if !defined(LUA_USE_C89) && defined(LLONG_MAX) && !defined(LUA_DEBUG) /* { */
+#if (!defined(LUA_USE_C89) && defined(LLONG_MAX) && !defined(LUA_DEBUG)) \
+ || defined(Rand64) /* { */
/*
** Assume long long.
*/
+#if !defined(Rand64)
/* a 64-bit value */
-typedef unsigned long long I;
+typedef unsigned long long Rand64;
+#endif
+
+
+/*
+** If 'Rand64' has more than 64 bits, the extra bits do not interfere
+** with the 64 initial bits, except in a right shift. Otherwise, we just
+** have to make sure we never use them.
+*/
+
+/* avoid using extra bits when needed */
+#define trim64(x) ((x) & 0xffffffffffffffff)
/* rotate left 'x' by 'n' bits */
-static I rotl (I x, int n) {
- return (x << n) | (x >> (64 - n));
+static Rand64 rotl (Rand64 x, int n) {
+ return (x << n) | (trim64(x) >> (64 - n));
}
-static I nextrand (I *state) {
- I s0 = state[0];
- I s1 = state[1];
- I res = s0 + s1;
- res = rotl(res, 41); /* extra step to change place of lower bits */
- s1 = s1 ^ s0;
- state[0] = rotl(s0, 55) ^ (s1 ^ (s1 << 14));
- state[1] = rotl(s1, 36);
+static Rand64 nextrand (Rand64 *state) {
+ Rand64 res = rotl(state[0] * 5, 7) * 9;
+ Rand64 t = state[1] << 17;
+ state[2] ^= state[0];
+ state[3] ^= state[1];
+ state[1] ^= state[2];
+ state[0] ^= state[3];
+ state[2] ^= t;
+ state[3] = rotl(state[3], 45);
return res;
}
@@ -298,15 +308,15 @@
#define maskFIG (~(~1LLU << (FIGS - 1))) /* use FIGS bits */
#define shiftFIG (l_mathop(0.5) / (1LLU << (FIGS - 1))) /* 2^(-FIGS) */
-static lua_Number I2d (I x) {
+static lua_Number I2d (Rand64 x) {
return (lua_Number)(x & maskFIG) * shiftFIG;
}
-/* convert an 'I' to a lua_Unsigned */
-#define I2UInt(x) ((lua_Unsigned)(x))
+/* convert a 'Rand64' to a 'lua_Unsigned' */
+#define I2UInt(x) ((lua_Unsigned)trim64(x))
-/* convert a lua_Unsigned to an 'I' */
-#define Int2I(x) ((I)(x))
+/* convert a 'lua_Unsigned' to an 'Rand64' */
+#define Int2I(x) ((Rand64)(x))
#else /* no long long }{ */
@@ -321,69 +331,92 @@
typedef unsigned long lu_int32;
#endif
+
/* a 64-bit value */
-typedef struct I {
+typedef struct Rand64 {
lu_int32 h; /* higher half */
lu_int32 l; /* lower half */
-} I;
+} Rand64;
/*
-** basic operations on 'I' values
+** If 'lu_int32' has more than 32 bits, the extra bits do not interfere
+** with the 32 initial bits, except in a right shift and comparisons.
+** Otherwise, we just have to make sure we never use them.
*/
-static I packI (lu_int32 h, lu_int32 l) {
- I result;
+/* avoid using extra bits when needed */
+#define trim32(x) ((x) & 0xffffffff)
+
+
+/*
+** basic operations on 'Rand64' values
+*/
+
+static Rand64 packI (lu_int32 h, lu_int32 l) {
+ Rand64 result;
result.h = h;
result.l = l;
return result;
}
-/* i ^ (i << n) */
-static I Ixorshl (I i, int n) {
+static Rand64 Ishl (Rand64 i, int n) {
lua_assert(n > 0 && n < 32);
- return packI(i.h ^ ((i.h << n) | (i.l >> (32 - n))), i.l ^ (i.l << n));
+ return packI((i.h << n) | (trim32(i.l) >> (32 - n)), i.l << n);
}
-static I Ixor (I i1, I i2) {
- return packI(i1.h ^ i2.h, i1.l ^ i2.l);
+static void Ixor (Rand64 *i1, Rand64 i2) {
+ i1->h ^= i2.h;
+ i1->l ^= i2.l;
}
-static I Iadd (I i1, I i2) {
- I result = packI(i1.h + i2.h, i1.l + i2.l);
- if (result.l < i1.l) /* carry? */
+static Rand64 Iadd (Rand64 i1, Rand64 i2) {
+ Rand64 result = packI(i1.h + i2.h, i1.l + i2.l);
+ if (trim32(result.l) < trim32(i1.l)) /* carry? */
result.h++;
return result;
}
-/*
-** Rotate left. As all offsets here are larger than 32, do a rotate right
-** of 64 - offset.
-*/
-static I Irotli (I i, int n) {
- n = 64 - n;
+static Rand64 times5 (Rand64 i) {
+ return Iadd(Ishl(i, 2), i); /* i * 5 == (i << 2) + i */
+}
+
+static Rand64 times9 (Rand64 i) {
+ return Iadd(Ishl(i, 3), i); /* i * 9 == (i << 3) + i */
+}
+
+static Rand64 rotl (Rand64 i, int n) {
lua_assert(n > 0 && n < 32);
- return packI((i.h >> n) | (i.l << (32 - n)),
- (i.h << (32 - n)) | (i.l >> n));
+ return packI((i.h << n) | (trim32(i.l) >> (32 - n)),
+ (trim32(i.h) >> (32 - n)) | (i.l << n));
+}
+
+/* for offsets larger than 32, rotate right by 64 - offset */
+static Rand64 rotl1 (Rand64 i, int n) {
+ lua_assert(n > 32 && n < 64);
+ n = 64 - n;
+ return packI((trim32(i.h) >> n) | (i.l << (32 - n)),
+ (i.h << (32 - n)) | (trim32(i.l) >> n));
}
/*
-** implementation of 'xoroshiro128+' algorithm on 'I' values
+** implementation of 'xoshiro256**' algorithm on 'Rand64' values
*/
-static I nextrand (I *state) {
- I s0 = state[0];
- I s1 = state[1];
- I res = Iadd(s0, s1);
- res = Irotli(res, 41);
- s1 = Ixor(s1, s0);
- state[0] = Ixor(Irotli(s0, 55), Ixorshl(s1, 14));
- state[1] = Irotli(s1, 36);
+static Rand64 nextrand (Rand64 *state) {
+ Rand64 res = times9(rotl(times5(state[0]), 7));
+ Rand64 t = Ishl(state[1], 17);
+ Ixor(&state[2], state[0]);
+ Ixor(&state[3], state[1]);
+ Ixor(&state[1], state[2]);
+ Ixor(&state[0], state[3]);
+ Ixor(&state[2], t);
+ state[3] = rotl1(state[3], 45);
return res;
}
/*
-** Converts an 'I' into a float.
+** Converts an 'Rand64' into a float.
*/
/* an unsigned 1 with proper type */
@@ -402,8 +435,8 @@
/* use FIGS - 32 bits from higher half */
#define maskHI (~(~UONE << (FIGS - 33)))
-/* use all bits from lower half */
-#define maskLOW (~(lu_int32)0)
+/* use 32 bits from lower half */
+#define maskLOW (~(~UONE << 31))
/* 2^(-FIGS) == (1 / 2^33) / 2^(FIGS-33) */
#define shiftFIG ((lua_Number)(1.0 / 8589934592.0) / (UONE << (FIGS - 33)))
@@ -412,30 +445,30 @@
#define twoto32 l_mathop(4294967296.0) /* 2^32 */
-static lua_Number I2d (I x) {
+static lua_Number I2d (Rand64 x) {
lua_Number h = (lua_Number)(x.h & maskHI);
lua_Number l = (lua_Number)(x.l & maskLOW);
return (h * twoto32 + l) * shiftFIG;
}
-static lua_Unsigned I2UInt (I x) {
- return ((lua_Unsigned)x.h << 31 << 1) | (lua_Unsigned)x.l;
+static lua_Unsigned I2UInt (Rand64 x) {
+ return ((lua_Unsigned)x.h << 31 << 1) | (lua_Unsigned)trim32(x.l);
}
-static I Int2I (lua_Unsigned n) {
- return packI((lu_int32)(n >> 31 >> 1), (lu_int32)n & ~(lu_int32)0);
+static Rand64 Int2I (lua_Unsigned n) {
+ return packI((lu_int32)(n >> 31 >> 1), (lu_int32)n);
}
#endif /* } */
/*
-** A state uses two 'I' values.
+** A state uses four 'Rand64' values.
*/
typedef struct {
- I s[2];
+ Rand64 s[4];
} RanState;
@@ -476,7 +509,7 @@
lua_Integer low, up;
lua_Unsigned p;
RanState *state = (RanState *)lua_touserdata(L, lua_upvalueindex(1));
- I rv = nextrand(state->s); /* next pseudo-random value */
+ Rand64 rv = nextrand(state->s); /* next pseudo-random value */
switch (lua_gettop(L)) { /* check number of arguments */
case 0: { /* no arguments */
lua_pushnumber(L, I2d(rv)); /* float between 0 and 1 */
@@ -507,10 +540,12 @@
}
-static void setseed (I *state, lua_Unsigned n) {
+static void setseed (Rand64 *state, lua_Unsigned n1, lua_Unsigned n2) {
int i;
- state[0] = Int2I(n);
+ state[0] = Int2I(n1);
state[1] = Int2I(0xff); /* avoid a zero state */
+ state[2] = Int2I(n2);
+ state[3] = Int2I(0);
for (i = 0; i < 16; i++)
nextrand(state); /* discard initial values to "spread" seed */
}
@@ -518,8 +553,9 @@
static int math_randomseed (lua_State *L) {
RanState *state = (RanState *)lua_touserdata(L, lua_upvalueindex(1));
- lua_Integer n = luaL_checkinteger(L, 1);
- setseed(state->s, n);
+ lua_Integer n1 = luaL_checkinteger(L, 1);
+ lua_Integer n2 = luaL_optinteger(L, 2, 0);
+ setseed(state->s, n1, n2);
return 0;
}
@@ -532,7 +568,7 @@
static void setrandfunc (lua_State *L) {
RanState *state = (RanState *)lua_newuserdatauv(L, sizeof(RanState), 0);
- setseed(state->s, 0);
+ setseed(state->s, 0, 0);
luaL_setfuncs(L, randfuncs, 1);
}
