ref: 89310461e81f069d353d4a53194c94258d9203b5
dir: /jsoptim.c/
#include "js.h" #include "jsparse.h" static inline int i32(double d) { double two32 = 4294967296.0; double two31 = 2147483648.0; if (!isfinite(d) || d == 0) return 0; d = fmod(d, two32); d = d >= 0 ? floor(d) : ceil(d) + two32; if (d >= two31) return d - two32; else return d; } static inline unsigned int u32(double d) { return i32(d); } static int N(js_Ast *node, double x) { node->type = AST_NUMBER; node->number = x; node->a = node->b = node->c = node->d = NULL; return 1; } static int foldnumber(js_Ast *node) { double x, y; int a, b; if (node->type == AST_NUMBER) return 1; a = node->a ? foldnumber(node->a) : 0; b = node->b ? foldnumber(node->b) : 0; if (node->c) foldnumber(node->c); if (node->d) foldnumber(node->d); if (a) { x = node->a->number; switch (node->type) { case EXP_NEG: return N(node, -x); case EXP_POS: return N(node, x); case EXP_BITNOT: return N(node, ~i32(x)); } if (b) { y = node->b->number; switch (node->type) { case EXP_MUL: return N(node, x * y); case EXP_DIV: return N(node, x / y); case EXP_MOD: return N(node, fmod(x, y)); case EXP_ADD: return N(node, x + y); case EXP_SUB: return N(node, x - y); case EXP_SHL: return N(node, i32(x) << (u32(y) & 0x1F)); case EXP_SHR: return N(node, i32(x) >> (u32(y) & 0x1F)); case EXP_USHR: return N(node, u32(x) >> (u32(y) & 0x1F)); case EXP_BITAND: return N(node, i32(x) & i32(y)); case EXP_BITXOR: return N(node, i32(x) ^ i32(y)); case EXP_BITOR: return N(node, i32(x) | i32(y)); } } } return 0; } void jsP_optimize(js_State *J, js_Ast *prog) { foldnumber(prog); }