src/runtime_math.js

#if POLYFILL_OLD_MATH_FUNCTIONS
// check for imul support, and also for correctness ( https://bugs.webkit.org/show_bug.cgi?id=126345 )
if (!Math.imul || Math.imul(0xffffffff, 5) !== -5) Math.imul = function imul(a, b) {
  var ah  = a >>> 16;
  var al = a & 0xffff;
  var bh  = b >>> 16;
  var bl = b & 0xffff;
  return (al*bl + ((ah*bl + al*bh) << 16))|0;
};

#if PRECISE_F32
#if PRECISE_F32 == 1
if (!Math.fround) {
  var froundBuffer = new Float32Array(1);
  Math.fround = function(x) { froundBuffer[0] = x; return froundBuffer[0] };
}
#else // 2
if (!Math.fround) Math.fround = function(x) { return x };
#endif
#else
#if SIMD
if (!Math.fround) Math.fround = function(x) { return x };
#endif
#endif

if (!Math.clz32) Math.clz32 = function(x) {
  var n = 32;
  var y = x >> 16; if (y) { n -= 16; x = y; }
  y = x >> 8; if (y) { n -= 8; x = y; }
  y = x >> 4; if (y) { n -= 4; x = y; }
  y = x >> 2; if (y) { n -= 2; x = y; }
  y = x >> 1; if (y) return n - 2;
  return n - x;
};

if (!Math.trunc) Math.trunc = function(x) {
  return x < 0 ? Math.ceil(x) : Math.floor(x);
};
#else // POLYFILL_OLD_MATH_FUNCTIONS
#if ASSERTIONS
assert(Math.imul, 'This browser does not support Math.imul(), build with LEGACY_VM_SUPPORT or POLYFILL_OLD_MATH_FUNCTIONS to add in a polyfill');
assert(Math.fround, 'This browser does not support Math.fround(), build with LEGACY_VM_SUPPORT or POLYFILL_OLD_MATH_FUNCTIONS to add in a polyfill');
assert(Math.clz32, 'This browser does not support Math.clz32(), build with LEGACY_VM_SUPPORT or POLYFILL_OLD_MATH_FUNCTIONS to add in a polyfill');
assert(Math.trunc, 'This browser does not support Math.trunc(), build with LEGACY_VM_SUPPORT or POLYFILL_OLD_MATH_FUNCTIONS to add in a polyfill');
#endif
#endif // LEGACY_VM_SUPPORT

var Math_abs = Math.abs;
var Math_cos = Math.cos;
var Math_sin = Math.sin;
var Math_tan = Math.tan;
var Math_acos = Math.acos;
var Math_asin = Math.asin;
var Math_atan = Math.atan;
var Math_atan2 = Math.atan2;
var Math_exp = Math.exp;
var Math_log = Math.log;
var Math_sqrt = Math.sqrt;
var Math_ceil = Math.ceil;
var Math_floor = Math.floor;
var Math_pow = Math.pow;
var Math_imul = Math.imul;
var Math_fround = Math.fround;
var Math_round = Math.round;
var Math_min = Math.min;
var Math_max = Math.max;
var Math_clz32 = Math.clz32;
var Math_trunc = Math.trunc;