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https://github.com/lua/lua
synced 2024-12-29 13:49:44 +03:00
PRNG changed from 'xoroshiro128+' to 'xoshiro256**' + "I' renamed 'Rand64'
+ implementation can use integer types larger than 64 (or 32) bits
This commit is contained in:
Roberto Ierusalimschy
parent
b44787652b
commit
b8a04658b2
178
lmathlib.c
178
lmathlib.c
@ -1,5 +1,5 @@
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/*
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** $Id: lmathlib.c,v 1.128 2018/03/26 19:48:46 roberto Exp $
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** $Id: lmathlib.c,v 1.129 2018/04/04 16:12:53 roberto Exp roberto $
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** Standard mathematical library
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** See Copyright Notice in lua.h
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*/
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@ -230,12 +230,8 @@ static int math_max (lua_State *L) {
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static int math_type (lua_State *L) {
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if (lua_type(L, 1) == LUA_TNUMBER) {
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if (lua_isinteger(L, 1))
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lua_pushliteral(L, "integer");
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else
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lua_pushliteral(L, "float");
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}
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if (lua_type(L, 1) == LUA_TNUMBER)
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lua_pushstring(L, (lua_isinteger(L, 1)) ? "integer" : "float");
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else {
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luaL_checkany(L, 1);
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lua_pushnil(L);
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@ -247,7 +243,7 @@ static int math_type (lua_State *L) {
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/*
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** {==================================================================
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** Pseudo-Random Number Generator based on 'xoroshiro128+'.
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** Pseudo-Random Number Generator based on 'xoshiro256**'.
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** ===================================================================
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*/
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@ -261,29 +257,43 @@ static int math_type (lua_State *L) {
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#endif
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#if !defined(LUA_USE_C89) && defined(LLONG_MAX) && !defined(LUA_DEBUG) /* { */
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#if (!defined(LUA_USE_C89) && defined(LLONG_MAX) && !defined(LUA_DEBUG)) \
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|| defined(Rand64) /* { */
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/*
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** Assume long long.
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*/
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#if !defined(Rand64)
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/* a 64-bit value */
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typedef unsigned long long I;
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typedef unsigned long long Rand64;
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#endif
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/*
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** If 'Rand64' has more than 64 bits, the extra bits do not interfere
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** with the 64 initial bits, except in a right shift. Otherwise, we just
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** have to make sure we never use them.
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*/
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/* avoid using extra bits when needed */
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#define trim64(x) ((x) & 0xffffffffffffffff)
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/* rotate left 'x' by 'n' bits */
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static I rotl (I x, int n) {
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return (x << n) | (x >> (64 - n));
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static Rand64 rotl (Rand64 x, int n) {
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return (x << n) | (trim64(x) >> (64 - n));
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}
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static I nextrand (I *state) {
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I s0 = state[0];
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I s1 = state[1];
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I res = s0 + s1;
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res = rotl(res, 41); /* extra step to change place of lower bits */
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s1 = s1 ^ s0;
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state[0] = rotl(s0, 55) ^ (s1 ^ (s1 << 14));
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state[1] = rotl(s1, 36);
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static Rand64 nextrand (Rand64 *state) {
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Rand64 res = rotl(state[0] * 5, 7) * 9;
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Rand64 t = state[1] << 17;
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state[2] ^= state[0];
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state[3] ^= state[1];
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state[1] ^= state[2];
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state[0] ^= state[3];
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state[2] ^= t;
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state[3] = rotl(state[3], 45);
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return res;
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}
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@ -298,15 +308,15 @@ static I nextrand (I *state) {
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#define maskFIG (~(~1LLU << (FIGS - 1))) /* use FIGS bits */
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#define shiftFIG (l_mathop(0.5) / (1LLU << (FIGS - 1))) /* 2^(-FIGS) */
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static lua_Number I2d (I x) {
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static lua_Number I2d (Rand64 x) {
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return (lua_Number)(x & maskFIG) * shiftFIG;
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}
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/* convert an 'I' to a lua_Unsigned */
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#define I2UInt(x) ((lua_Unsigned)(x))
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/* convert a 'Rand64' to a 'lua_Unsigned' */
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#define I2UInt(x) ((lua_Unsigned)trim64(x))
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/* convert a lua_Unsigned to an 'I' */
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#define Int2I(x) ((I)(x))
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/* convert a 'lua_Unsigned' to an 'Rand64' */
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#define Int2I(x) ((Rand64)(x))
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#else /* no long long }{ */
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@ -321,69 +331,92 @@ typedef unsigned int lu_int32;
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typedef unsigned long lu_int32;
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#endif
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/* a 64-bit value */
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typedef struct I {
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typedef struct Rand64 {
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lu_int32 h; /* higher half */
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lu_int32 l; /* lower half */
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} I;
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} Rand64;
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/*
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** basic operations on 'I' values
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** If 'lu_int32' has more than 32 bits, the extra bits do not interfere
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** with the 32 initial bits, except in a right shift and comparisons.
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** Otherwise, we just have to make sure we never use them.
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*/
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static I packI (lu_int32 h, lu_int32 l) {
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I result;
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/* avoid using extra bits when needed */
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#define trim32(x) ((x) & 0xffffffff)
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/*
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** basic operations on 'Rand64' values
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*/
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static Rand64 packI (lu_int32 h, lu_int32 l) {
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Rand64 result;
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result.h = h;
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result.l = l;
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return result;
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}
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/* i ^ (i << n) */
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static I Ixorshl (I i, int n) {
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static Rand64 Ishl (Rand64 i, int n) {
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lua_assert(n > 0 && n < 32);
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return packI(i.h ^ ((i.h << n) | (i.l >> (32 - n))), i.l ^ (i.l << n));
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return packI((i.h << n) | (trim32(i.l) >> (32 - n)), i.l << n);
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}
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static I Ixor (I i1, I i2) {
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return packI(i1.h ^ i2.h, i1.l ^ i2.l);
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static void Ixor (Rand64 *i1, Rand64 i2) {
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i1->h ^= i2.h;
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i1->l ^= i2.l;
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}
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static I Iadd (I i1, I i2) {
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I result = packI(i1.h + i2.h, i1.l + i2.l);
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if (result.l < i1.l) /* carry? */
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static Rand64 Iadd (Rand64 i1, Rand64 i2) {
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Rand64 result = packI(i1.h + i2.h, i1.l + i2.l);
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if (trim32(result.l) < trim32(i1.l)) /* carry? */
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result.h++;
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return result;
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}
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/*
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** Rotate left. As all offsets here are larger than 32, do a rotate right
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** of 64 - offset.
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*/
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static I Irotli (I i, int n) {
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n = 64 - n;
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static Rand64 times5 (Rand64 i) {
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return Iadd(Ishl(i, 2), i); /* i * 5 == (i << 2) + i */
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}
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static Rand64 times9 (Rand64 i) {
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return Iadd(Ishl(i, 3), i); /* i * 9 == (i << 3) + i */
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}
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static Rand64 rotl (Rand64 i, int n) {
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lua_assert(n > 0 && n < 32);
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return packI((i.h >> n) | (i.l << (32 - n)),
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(i.h << (32 - n)) | (i.l >> n));
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return packI((i.h << n) | (trim32(i.l) >> (32 - n)),
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(trim32(i.h) >> (32 - n)) | (i.l << n));
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}
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/* for offsets larger than 32, rotate right by 64 - offset */
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static Rand64 rotl1 (Rand64 i, int n) {
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lua_assert(n > 32 && n < 64);
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n = 64 - n;
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return packI((trim32(i.h) >> n) | (i.l << (32 - n)),
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(i.h << (32 - n)) | (trim32(i.l) >> n));
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}
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/*
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** implementation of 'xoroshiro128+' algorithm on 'I' values
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** implementation of 'xoshiro256**' algorithm on 'Rand64' values
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*/
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static I nextrand (I *state) {
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I s0 = state[0];
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I s1 = state[1];
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I res = Iadd(s0, s1);
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res = Irotli(res, 41);
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s1 = Ixor(s1, s0);
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state[0] = Ixor(Irotli(s0, 55), Ixorshl(s1, 14));
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state[1] = Irotli(s1, 36);
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static Rand64 nextrand (Rand64 *state) {
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Rand64 res = times9(rotl(times5(state[0]), 7));
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Rand64 t = Ishl(state[1], 17);
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Ixor(&state[2], state[0]);
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Ixor(&state[3], state[1]);
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Ixor(&state[1], state[2]);
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Ixor(&state[0], state[3]);
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Ixor(&state[2], t);
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state[3] = rotl1(state[3], 45);
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return res;
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}
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/*
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** Converts an 'I' into a float.
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** Converts an 'Rand64' into a float.
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*/
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/* an unsigned 1 with proper type */
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@ -402,8 +435,8 @@ static I nextrand (I *state) {
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/* use FIGS - 32 bits from higher half */
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#define maskHI (~(~UONE << (FIGS - 33)))
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/* use all bits from lower half */
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#define maskLOW (~(lu_int32)0)
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/* use 32 bits from lower half */
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#define maskLOW (~(~UONE << 31))
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/* 2^(-FIGS) == (1 / 2^33) / 2^(FIGS-33) */
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#define shiftFIG ((lua_Number)(1.0 / 8589934592.0) / (UONE << (FIGS - 33)))
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@ -412,30 +445,30 @@ static I nextrand (I *state) {
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#define twoto32 l_mathop(4294967296.0) /* 2^32 */
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static lua_Number I2d (I x) {
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static lua_Number I2d (Rand64 x) {
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lua_Number h = (lua_Number)(x.h & maskHI);
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lua_Number l = (lua_Number)(x.l & maskLOW);
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return (h * twoto32 + l) * shiftFIG;
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}
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static lua_Unsigned I2UInt (I x) {
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return ((lua_Unsigned)x.h << 31 << 1) | (lua_Unsigned)x.l;
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static lua_Unsigned I2UInt (Rand64 x) {
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return ((lua_Unsigned)x.h << 31 << 1) | (lua_Unsigned)trim32(x.l);
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}
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static I Int2I (lua_Unsigned n) {
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return packI((lu_int32)(n >> 31 >> 1), (lu_int32)n & ~(lu_int32)0);
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static Rand64 Int2I (lua_Unsigned n) {
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return packI((lu_int32)(n >> 31 >> 1), (lu_int32)n);
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}
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#endif /* } */
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/*
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** A state uses two 'I' values.
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** A state uses four 'Rand64' values.
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*/
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typedef struct {
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I s[2];
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Rand64 s[4];
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} RanState;
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@ -476,7 +509,7 @@ static int math_random (lua_State *L) {
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lua_Integer low, up;
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lua_Unsigned p;
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RanState *state = (RanState *)lua_touserdata(L, lua_upvalueindex(1));
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I rv = nextrand(state->s); /* next pseudo-random value */
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Rand64 rv = nextrand(state->s); /* next pseudo-random value */
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switch (lua_gettop(L)) { /* check number of arguments */
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case 0: { /* no arguments */
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lua_pushnumber(L, I2d(rv)); /* float between 0 and 1 */
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@ -507,10 +540,12 @@ static int math_random (lua_State *L) {
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}
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static void setseed (I *state, lua_Unsigned n) {
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static void setseed (Rand64 *state, lua_Unsigned n1, lua_Unsigned n2) {
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int i;
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state[0] = Int2I(n);
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state[0] = Int2I(n1);
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state[1] = Int2I(0xff); /* avoid a zero state */
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state[2] = Int2I(n2);
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state[3] = Int2I(0);
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for (i = 0; i < 16; i++)
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nextrand(state); /* discard initial values to "spread" seed */
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}
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@ -518,8 +553,9 @@ static void setseed (I *state, lua_Unsigned n) {
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static int math_randomseed (lua_State *L) {
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RanState *state = (RanState *)lua_touserdata(L, lua_upvalueindex(1));
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lua_Integer n = luaL_checkinteger(L, 1);
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setseed(state->s, n);
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lua_Integer n1 = luaL_checkinteger(L, 1);
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lua_Integer n2 = luaL_optinteger(L, 2, 0);
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setseed(state->s, n1, n2);
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return 0;
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}
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@ -532,7 +568,7 @@ static const luaL_Reg randfuncs[] = {
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static void setrandfunc (lua_State *L) {
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RanState *state = (RanState *)lua_newuserdatauv(L, sizeof(RanState), 0);
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setseed(state->s, 0);
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setseed(state->s, 0, 0);
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luaL_setfuncs(L, randfuncs, 1);
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}
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