src/lib_math.c

   1 /*
   2 ** Math library.
   3 ** Copyright (C) 2005-2023 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_lib.h"
  17 #include "lj_vm.h"
  18 #include "lj_prng.h"
  19
  20 /* ------------------------------------------------------------------------ */
  21
  22 #define LJLIB_MODULE_math
  23
  24 LJLIB_ASM(math_abs)             LJLIB_REC(.)
  25 {
  26   lj_lib_checknumber(L, 1);
  27   return FFH_RETRY;
  28 }
  29 LJLIB_ASM_(math_floor)          LJLIB_REC(math_round IRFPM_FLOOR)
  30 LJLIB_ASM_(math_ceil)           LJLIB_REC(math_round IRFPM_CEIL)
  31
  32 LJLIB_ASM(math_sqrt)            LJLIB_REC(math_unary IRFPM_SQRT)
  33 {
  34   lj_lib_checknum(L, 1);
  35   return FFH_RETRY;
  36 }
  37 LJLIB_ASM_(math_log10)          LJLIB_REC(math_call IRCALL_log10)
  38 LJLIB_ASM_(math_exp)            LJLIB_REC(math_call IRCALL_exp)
  39 LJLIB_ASM_(math_sin)            LJLIB_REC(math_call IRCALL_sin)
  40 LJLIB_ASM_(math_cos)            LJLIB_REC(math_call IRCALL_cos)
  41 LJLIB_ASM_(math_tan)            LJLIB_REC(math_call IRCALL_tan)
  42 LJLIB_ASM_(math_asin)           LJLIB_REC(math_call IRCALL_asin)
  43 LJLIB_ASM_(math_acos)           LJLIB_REC(math_call IRCALL_acos)
  44 LJLIB_ASM_(math_atan)           LJLIB_REC(math_call IRCALL_atan)
  45 LJLIB_ASM_(math_sinh)           LJLIB_REC(math_call IRCALL_sinh)
  46 LJLIB_ASM_(math_cosh)           LJLIB_REC(math_call IRCALL_cosh)
  47 LJLIB_ASM_(math_tanh)           LJLIB_REC(math_call IRCALL_tanh)
  48 LJLIB_ASM_(math_frexp)
  49 LJLIB_ASM_(math_modf)
  50
  51 LJLIB_ASM(math_log)             LJLIB_REC(math_log)
  52 {
  53   double x = lj_lib_checknum(L, 1);
  54   if (L->base+1 < L->top) {
  55     double y = lj_lib_checknum(L, 2);
  56 #ifdef LUAJIT_NO_LOG2
  57     x = log(x); y = 1.0 / log(y);
  58 #else
  59     x = lj_vm_log2(x); y = 1.0 / lj_vm_log2(y);
  60 #endif
  61     setnumV(L->base-1-LJ_FR2, x*y);  /* Do NOT join the expression to x / y. */
  62     return FFH_RES(1);
  63   }
  64   return FFH_RETRY;
  65 }
  66
  67 LJLIB_LUA(math_deg) /* function(x) return x * 57.29577951308232 end */
  68 LJLIB_LUA(math_rad) /* function(x) return x * 0.017453292519943295 end */
  69
  70 LJLIB_ASM(math_atan2)           LJLIB_REC(.)
  71 {
  72   lj_lib_checknum(L, 1);
  73   lj_lib_checknum(L, 2);
  74   return FFH_RETRY;
  75 }
  76 LJLIB_ASM_(math_pow)            LJLIB_REC(.)
  77 LJLIB_ASM_(math_fmod)
  78
  79 LJLIB_ASM(math_ldexp)           LJLIB_REC(.)
  80 {
  81   lj_lib_checknum(L, 1);
  82 #if LJ_DUALNUM && !LJ_TARGET_X86ORX64
  83   lj_lib_checkint(L, 2);
  84 #else
  85   lj_lib_checknum(L, 2);
  86 #endif
  87   return FFH_RETRY;
  88 }
  89
  90 LJLIB_ASM(math_min)             LJLIB_REC(math_minmax IR_MIN)
  91 {
  92   int i = 0;
  93   do { lj_lib_checknumber(L, ++i); } while (L->base+i < L->top);
  94   return FFH_RETRY;
  95 }
  96 LJLIB_ASM_(math_max)            LJLIB_REC(math_minmax IR_MAX)
  97
  98 LJLIB_PUSH(3.14159265358979323846) LJLIB_SET(pi)
  99 LJLIB_PUSH(1e310) LJLIB_SET(huge)
 100
 101 /* ------------------------------------------------------------------------ */
 102
 103 /* This implements a Tausworthe PRNG with period 2^223. Based on:
 104 **   Tables of maximally-equidistributed combined LFSR generators,
 105 **   Pierre L'Ecuyer, 1991, table 3, 1st entry.
 106 ** Full-period ME-CF generator with L=64, J=4, k=223, N1=49.
 107 */
 108
 109 /* Union needed for bit-pattern conversion between uint64_t and double. */
 110 typedef union { uint64_t u64; double d; } U64double;
 111
 112 /* PRNG seeding function. */
 113 static void random_seed(PRNGState *rs, double d)
 114 {
 115   uint32_t r = 0x11090601;  /* 64-k[i] as four 8 bit constants. */
 116   int i;
 117   for (i = 0; i < 4; i++) {
 118     U64double u;
 119     uint32_t m = 1u << (r&255);
 120     r >>= 8;
 121     u.d = d = d * 3.14159265358979323846 + 2.7182818284590452354;
 122     if (u.u64 < m) u.u64 += m;  /* Ensure k[i] MSB of u[i] are non-zero. */
 123     rs->u[i] = u.u64;
 124   }
 125   for (i = 0; i < 10; i++)
 126     (void)lj_prng_u64(rs);
 127 }
 128
 129 /* PRNG extract function. */
 130 LJLIB_PUSH(top-2)  /* Upvalue holds userdata with PRNGState. */
 131 LJLIB_CF(math_random)           LJLIB_REC(.)
 132 {
 133   int n = (int)(L->top - L->base);
 134   PRNGState *rs = (PRNGState *)(uddata(udataV(lj_lib_upvalue(L, 1))));
 135   U64double u;
 136   double d;
 137   u.u64 = lj_prng_u64d(rs);
 138   d = u.d - 1.0;
 139   if (n > 0) {
 140 #if LJ_DUALNUM
 141     int isint = 1;
 142     double r1;
 143     lj_lib_checknumber(L, 1);
 144     if (tvisint(L->base)) {
 145       r1 = (lua_Number)intV(L->base);
 146     } else {
 147       isint = 0;
 148       r1 = numV(L->base);
 149     }
 150 #else
 151     double r1 = lj_lib_checknum(L, 1);
 152 #endif
 153     if (n == 1) {
 154       d = lj_vm_floor(d*r1) + 1.0;  /* d is an int in range [1, r1] */
 155     } else {
 156 #if LJ_DUALNUM
 157       double r2;
 158       lj_lib_checknumber(L, 2);
 159       if (tvisint(L->base+1)) {
 160         r2 = (lua_Number)intV(L->base+1);
 161       } else {
 162         isint = 0;
 163         r2 = numV(L->base+1);
 164       }
 165 #else
 166       double r2 = lj_lib_checknum(L, 2);
 167 #endif
 168       d = lj_vm_floor(d*(r2-r1+1.0)) + r1;  /* d is an int in range [r1, r2] */
 169     }
 170 #if LJ_DUALNUM
 171     if (isint) {
 172       setintV(L->top-1, lj_num2int(d));
 173       return 1;
 174     }
 175 #endif
 176   }  /* else: d is a double in range [0, 1] */
 177   setnumV(L->top++, d);
 178   return 1;
 179 }
 180
 181 /* PRNG seed function. */
 182 LJLIB_PUSH(top-2)  /* Upvalue holds userdata with PRNGState. */
 183 LJLIB_CF(math_randomseed)
 184 {
 185   PRNGState *rs = (PRNGState *)(uddata(udataV(lj_lib_upvalue(L, 1))));
 186   random_seed(rs, lj_lib_checknum(L, 1));
 187   return 0;
 188 }
 189
 190 /* ------------------------------------------------------------------------ */
 191
 192 #include "lj_libdef.h"
 193
 194 LUALIB_API int luaopen_math(lua_State *L)
 195 {
 196   PRNGState *rs = (PRNGState *)lua_newuserdata(L, sizeof(PRNGState));
 197   lj_prng_seed_fixed(rs);
 198   LJ_LIB_REG(L, LUA_MATHLIBNAME, math);
 199   return 1;
 200 }
 201