1/*
2** Math helper functions for assembler VM.
3** Copyright (C) 2005-2021 Mike Pall. See Copyright Notice in luajit.h
4*/
5
6#define lj_vmmath_c
7#define LUA_CORE
8
9#include <errno.h>
10#include <math.h>
11
12#include "lj_obj.h"
13#include "lj_ir.h"
14#include "lj_vm.h"
15
16/* -- Wrapper functions --------------------------------------------------- */
17
18#if LJ_TARGET_X86 && __ELF__ && __PIC__
19/* Wrapper functions to deal with the ELF/x86 PIC disaster. */
20LJ_FUNCA double lj_wrap_log(double x) { return log(x); }
21LJ_FUNCA double lj_wrap_log10(double x) { return log10(x); }
22LJ_FUNCA double lj_wrap_exp(double x) { return exp(x); }
23LJ_FUNCA double lj_wrap_sin(double x) { return sin(x); }
24LJ_FUNCA double lj_wrap_cos(double x) { return cos(x); }
25LJ_FUNCA double lj_wrap_tan(double x) { return tan(x); }
26LJ_FUNCA double lj_wrap_asin(double x) { return asin(x); }
27LJ_FUNCA double lj_wrap_acos(double x) { return acos(x); }
28LJ_FUNCA double lj_wrap_atan(double x) { return atan(x); }
29LJ_FUNCA double lj_wrap_sinh(double x) { return sinh(x); }
30LJ_FUNCA double lj_wrap_cosh(double x) { return cosh(x); }
31LJ_FUNCA double lj_wrap_tanh(double x) { return tanh(x); }
32LJ_FUNCA double lj_wrap_atan2(double x, double y) { return atan2(x, y); }
33LJ_FUNCA double lj_wrap_pow(double x, double y) { return pow(x, y); }
34LJ_FUNCA double lj_wrap_fmod(double x, double y) { return fmod(x, y); }
35#endif
36
37/* -- Helper functions for generated machine code ------------------------- */
38
39double lj_vm_foldarith(double x, double y, int op)
40{
41 switch (op) {
42 case IR_ADD - IR_ADD: return x+y; break;
43 case IR_SUB - IR_ADD: return x-y; break;
44 case IR_MUL - IR_ADD: return x*y; break;
45 case IR_DIV - IR_ADD: return x/y; break;
46 case IR_MOD - IR_ADD: return x-lj_vm_floor(x/y)*y; break;
47 case IR_POW - IR_ADD: return pow(x, y); break;
48 case IR_NEG - IR_ADD: return -x; break;
49 case IR_ABS - IR_ADD: return fabs(x); break;
50#if LJ_HASJIT
51 case IR_LDEXP - IR_ADD: return ldexp(x, (int)y); break;
52 case IR_MIN - IR_ADD: return x < y ? x : y; break;
53 case IR_MAX - IR_ADD: return x > y ? x : y; break;
54#endif
55 default: return x;
56 }
57}
58
59#if (LJ_HASJIT && !(LJ_TARGET_ARM || LJ_TARGET_ARM64 || LJ_TARGET_PPC)) || LJ_TARGET_MIPS
60int32_t LJ_FASTCALL lj_vm_modi(int32_t a, int32_t b)
61{
62 uint32_t y, ua, ub;
63 /* This must be checked before using this function. */
64 lj_assertX(b != 0, "modulo with zero divisor");
65 ua = a < 0 ? (uint32_t)-a : (uint32_t)a;
66 ub = b < 0 ? (uint32_t)-b : (uint32_t)b;
67 y = ua % ub;
68 if (y != 0 && (a^b) < 0) y = y - ub;
69 if (((int32_t)y^b) < 0) y = (uint32_t)-(int32_t)y;
70 return (int32_t)y;
71}
72#endif
73
74#if LJ_HASJIT
75
76#ifdef LUAJIT_NO_LOG2
77double lj_vm_log2(double a)
78{
79 return log(a) * 1.4426950408889634074;
80}
81#endif
82
83#if !LJ_TARGET_X86ORX64
84/* Unsigned x^k. */
85static double lj_vm_powui(double x, uint32_t k)
86{
87 double y;
88 lj_assertX(k != 0, "pow with zero exponent");
89 for (; (k & 1) == 0; k >>= 1) x *= x;
90 y = x;
91 if ((k >>= 1) != 0) {
92 for (;;) {
93 x *= x;
94 if (k == 1) break;
95 if (k & 1) y *= x;
96 k >>= 1;
97 }
98 y *= x;
99 }
100 return y;
101}
102
103/* Signed x^k. */
104double lj_vm_powi(double x, int32_t k)
105{
106 if (k > 1)
107 return lj_vm_powui(x, (uint32_t)k);
108 else if (k == 1)
109 return x;
110 else if (k == 0)
111 return 1.0;
112 else
113 return 1.0 / lj_vm_powui(x, (uint32_t)-k);
114}
115#endif
116
117/* Computes fpm(x) for extended math functions. */
118double lj_vm_foldfpm(double x, int fpm)
119{
120 switch (fpm) {
121 case IRFPM_FLOOR: return lj_vm_floor(x);
122 case IRFPM_CEIL: return lj_vm_ceil(x);
123 case IRFPM_TRUNC: return lj_vm_trunc(x);
124 case IRFPM_SQRT: return sqrt(x);
125 case IRFPM_LOG: return log(x);
126 case IRFPM_LOG2: return lj_vm_log2(x);
127 default: lj_assertX(0, "bad fpm %d", fpm);
128 }
129 return 0;
130}
131
132#if LJ_HASFFI
133int lj_vm_errno(void)
134{
135 return errno;
136}
137#endif
138
139#endif
140