src/lib_math.c

   1 /*
   2 ** Math library.
   3 ** Copyright (C) 2005-2025 Mike Pall. See Copyright Notice in luajit.h
   4 */
   5
   6 #include <math.h>
   7
   8 #define lib_math_c
   9 #define LUA_LIB
  10
  11 #include "lua.h"
  12 #include "lauxlib.h"
  13 #include "lualib.h"
  14
  15 #include "lj_obj.h"
  16 #include "lj_err.h"
  17 #include "lj_lib.h"
  18 #include "lj_vm.h"
  19 #include "lj_prng.h"
  20
  21 /* ------------------------------------------------------------------------ */
  22
  23 #define LJLIB_MODULE_math
  24
  25 LJLIB_ASM(math_abs)             LJLIB_REC(.)
  26 {
  27   lj_lib_checknumber(L, 1);
  28   return FFH_RETRY;
  29 }
  30 LJLIB_ASM_(math_floor)          LJLIB_REC(math_round IRFPM_FLOOR)
  31 LJLIB_ASM_(math_ceil)           LJLIB_REC(math_round IRFPM_CEIL)
  32
  33 LJLIB_ASM(math_sqrt)            LJLIB_REC(math_unary IRFPM_SQRT)
  34 {
  35   lj_lib_checknum(L, 1);
  36   return FFH_RETRY;
  37 }
  38 LJLIB_ASM_(math_log10)          LJLIB_REC(math_call IRCALL_log10)
  39 LJLIB_ASM_(math_exp)            LJLIB_REC(math_call IRCALL_exp)
  40 LJLIB_ASM_(math_sin)            LJLIB_REC(math_call IRCALL_sin)
  41 LJLIB_ASM_(math_cos)            LJLIB_REC(math_call IRCALL_cos)
  42 LJLIB_ASM_(math_tan)            LJLIB_REC(math_call IRCALL_tan)
  43 LJLIB_ASM_(math_asin)           LJLIB_REC(math_call IRCALL_asin)
  44 LJLIB_ASM_(math_acos)           LJLIB_REC(math_call IRCALL_acos)
  45 LJLIB_ASM_(math_atan)           LJLIB_REC(math_call IRCALL_atan)
  46 LJLIB_ASM_(math_sinh)           LJLIB_REC(math_call IRCALL_sinh)
  47 LJLIB_ASM_(math_cosh)           LJLIB_REC(math_call IRCALL_cosh)
  48 LJLIB_ASM_(math_tanh)           LJLIB_REC(math_call IRCALL_tanh)
  49 LJLIB_ASM_(math_frexp)
  50 LJLIB_ASM_(math_modf)
  51
  52 LJLIB_ASM(math_log)             LJLIB_REC(math_log)
  53 {
  54   double x = lj_lib_checknum(L, 1);
  55   if (L->base+1 < L->top) {
  56     double y = lj_lib_checknum(L, 2);
  57 #ifdef LUAJIT_NO_LOG2
  58     x = log(x); y = 1.0 / log(y);
  59 #else
  60     x = lj_vm_log2(x); y = 1.0 / lj_vm_log2(y);
  61 #endif
  62     setnumV(L->base-1-LJ_FR2, x*y);  /* Do NOT join the expression to x / y. */
  63     return FFH_RES(1);
  64   }
  65   return FFH_RETRY;
  66 }
  67
  68 LJLIB_LUA(math_deg) /* function(x) return x * 57.29577951308232 end */
  69 LJLIB_LUA(math_rad) /* function(x) return x * 0.017453292519943295 end */
  70
  71 LJLIB_ASM(math_atan2)           LJLIB_REC(.)
  72 {
  73   lj_lib_checknum(L, 1);
  74   lj_lib_checknum(L, 2);
  75   return FFH_RETRY;
  76 }
  77 LJLIB_ASM_(math_pow)            LJLIB_REC(.)
  78 LJLIB_ASM_(math_fmod)
  79
  80 LJLIB_ASM(math_ldexp)           LJLIB_REC(.)
  81 {
  82   lj_lib_checknum(L, 1);
  83 #if LJ_DUALNUM && !LJ_TARGET_X86ORX64
  84   lj_lib_checkint(L, 2);
  85 #else
  86   lj_lib_checknum(L, 2);
  87 #endif
  88   return FFH_RETRY;
  89 }
  90
  91 LJLIB_ASM(math_min)             LJLIB_REC(math_minmax IR_MIN)
  92 {
  93   int i = 0;
  94   do { lj_lib_checknumber(L, ++i); } while (L->base+i < L->top);
  95   return FFH_RETRY;
  96 }
  97 LJLIB_ASM_(math_max)            LJLIB_REC(math_minmax IR_MAX)
  98
  99 LJLIB_PUSH(3.14159265358979323846) LJLIB_SET(pi)
 100 LJLIB_PUSH(1e310) LJLIB_SET(huge)
 101
 102 /* ------------------------------------------------------------------------ */
 103
 104 /* This implements a Tausworthe PRNG with period 2^223. Based on:
 105 **   Tables of maximally-equidistributed combined LFSR generators,
 106 **   Pierre L'Ecuyer, 1991, table 3, 1st entry.
 107 ** Full-period ME-CF generator with L=64, J=4, k=223, N1=49.
 108 */
 109
 110 /* Union needed for bit-pattern conversion between uint64_t and double. */
 111 typedef union { uint64_t u64; double d; } U64double;
 112
 113 /* PRNG seeding function. */
 114 static void random_seed(PRNGState *rs, double d)
 115 {
 116   uint32_t r = 0x11090601;  /* 64-k[i] as four 8 bit constants. */
 117   int i;
 118   for (i = 0; i < 4; i++) {
 119     U64double u;
 120     uint32_t m = 1u << (r&255);
 121     r >>= 8;
 122     u.d = d = d * 3.14159265358979323846 + 2.7182818284590452354;
 123     if (u.u64 < m) u.u64 += m;  /* Ensure k[i] MSB of u[i] are non-zero. */
 124     rs->u[i] = u.u64;
 125   }
 126   for (i = 0; i < 10; i++)
 127     (void)lj_prng_u64(rs);
 128 }
 129
 130 /* PRNG extract function. */
 131 LJLIB_PUSH(top-2)  /* Upvalue holds userdata with PRNGState. */
 132 LJLIB_CF(math_random)           LJLIB_REC(.)
 133 {
 134   int n = (int)(L->top - L->base);
 135   PRNGState *rs = (PRNGState *)(uddata(udataV(lj_lib_upvalue(L, 1))));
 136   U64double u;
 137   double d;
 138   u.u64 = lj_prng_u64d(rs);
 139   d = u.d - 1.0;
 140   if (n > 0) {
 141 #if LJ_DUALNUM
 142     int isint = 1;
 143     double r1;
 144     lj_lib_checknumber(L, 1);
 145     if (tvisint(L->base)) {
 146       r1 = (lua_Number)intV(L->base);
 147     } else {
 148       isint = 0;
 149       r1 = numV(L->base);
 150     }
 151 #else
 152     double r1 = lj_lib_checknum(L, 1);
 153 #endif
 154     if (n == 1) {
 155       d = lj_vm_floor(d*r1) + 1.0;  /* d is an int in range [1, r1] */
 156     } else {
 157 #if LJ_DUALNUM
 158       double r2;
 159       lj_lib_checknumber(L, 2);
 160       if (tvisint(L->base+1)) {
 161         r2 = (lua_Number)intV(L->base+1);
 162       } else {
 163         isint = 0;
 164         r2 = numV(L->base+1);
 165       }
 166 #else
 167       double r2 = lj_lib_checknum(L, 2);
 168 #endif
 169       d = lj_vm_floor(d*(r2-r1+1.0)) + r1;  /* d is an int in range [r1, r2] */
 170     }
 171 #if LJ_DUALNUM
 172     if (isint) {
 173       setintV(L->top-1, lj_num2int(d));
 174       return 1;
 175     }
 176 #endif
 177   }  /* else: d is a double in range [0, 1] */
 178   setnumV(L->top++, d);
 179   return 1;
 180 }
 181
 182 /* PRNG seed function. */
 183 LJLIB_PUSH(top-2)  /* Upvalue holds userdata with PRNGState. */
 184 LJLIB_CF(math_randomseed)
 185 {
 186   PRNGState *rs = (PRNGState *)(uddata(udataV(lj_lib_upvalue(L, 1))));
 187   if (L->base != L->top)
 188     random_seed(rs, lj_lib_checknum(L, 1));
 189   else if (!lj_prng_seed_secure(rs))
 190     lj_err_caller(L, LJ_ERR_PRNGSD);
 191   return 0;
 192 }
 193
 194 /* ------------------------------------------------------------------------ */
 195
 196 #include "lj_libdef.h"
 197
 198 LUALIB_API int luaopen_math(lua_State *L)
 199 {
 200   PRNGState *rs = (PRNGState *)lua_newuserdata(L, sizeof(PRNGState));
 201   lj_prng_seed_fixed(rs);
 202   LJ_LIB_REG(L, LUA_MATHLIBNAME, math);
 203   return 1;
 204 }
 205