JSBool /* ES5 15.8.2.15. */
js_math_round(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setDouble(js_NaN);
return true;
}
double x;
if (!ToNumber(cx, args[0], &x))
return false;
int32_t i;
if (DoubleIsInt32(x, &i)) {
args.rval().setInt32(i);
return true;
}
/* Some numbers are so big that adding 0.5 would give the wrong number. */
if (ExponentComponent(x) >= 52) {
args.rval().setNumber(x);
return true;
}
args.rval().setNumber(js_copysign(floor(x + 0.5), x));
return true;
}
double
js::math_round_impl(double x)
{
int32_t i;
if (DoubleIsInt32(x, &i))
return double(i);
/* Some numbers are so big that adding 0.5 would give the wrong number. */
if (ExponentComponent(x) >= 52)
return x;
return js_copysign(floor(x + 0.5), x);
}
static void
TestPredicates()
{
MOZ_ASSERT(IsNaN(UnspecifiedNaN()));
MOZ_ASSERT(IsNaN(SpecificNaN(1, 17)));;
MOZ_ASSERT(IsNaN(SpecificNaN(0, 0xfffffffffff0fULL)));
MOZ_ASSERT(!IsNaN(0));
MOZ_ASSERT(!IsNaN(-0.0));
MOZ_ASSERT(!IsNaN(1.0));
MOZ_ASSERT(!IsNaN(PositiveInfinity()));
MOZ_ASSERT(!IsNaN(NegativeInfinity()));
MOZ_ASSERT(IsInfinite(PositiveInfinity()));
MOZ_ASSERT(IsInfinite(NegativeInfinity()));
MOZ_ASSERT(!IsInfinite(UnspecifiedNaN()));
MOZ_ASSERT(!IsInfinite(0));
MOZ_ASSERT(!IsInfinite(-0.0));
MOZ_ASSERT(!IsInfinite(1.0));
MOZ_ASSERT(!IsFinite(PositiveInfinity()));
MOZ_ASSERT(!IsFinite(NegativeInfinity()));
MOZ_ASSERT(!IsFinite(UnspecifiedNaN()));
MOZ_ASSERT(IsFinite(0));
MOZ_ASSERT(IsFinite(-0.0));
MOZ_ASSERT(IsFinite(1.0));
MOZ_ASSERT(!IsNegative(PositiveInfinity()));
MOZ_ASSERT(IsNegative(NegativeInfinity()));
MOZ_ASSERT(IsNegative(-0.0));
MOZ_ASSERT(!IsNegative(0.0));
MOZ_ASSERT(IsNegative(-1.0));
MOZ_ASSERT(!IsNegative(1.0));
MOZ_ASSERT(!IsNegativeZero(PositiveInfinity()));
MOZ_ASSERT(!IsNegativeZero(NegativeInfinity()));
MOZ_ASSERT(!IsNegativeZero(SpecificNaN(1, 17)));;
MOZ_ASSERT(!IsNegativeZero(SpecificNaN(1, 0xfffffffffff0fULL)));
MOZ_ASSERT(!IsNegativeZero(SpecificNaN(0, 17)));;
MOZ_ASSERT(!IsNegativeZero(SpecificNaN(0, 0xfffffffffff0fULL)));
MOZ_ASSERT(!IsNegativeZero(UnspecifiedNaN()));
MOZ_ASSERT(IsNegativeZero(-0.0));
MOZ_ASSERT(!IsNegativeZero(0.0));
MOZ_ASSERT(!IsNegativeZero(-1.0));
MOZ_ASSERT(!IsNegativeZero(1.0));
int32_t i;
MOZ_ASSERT(DoubleIsInt32(0.0, &i)); MOZ_ASSERT(i == 0);
MOZ_ASSERT(!DoubleIsInt32(-0.0, &i));
MOZ_ASSERT(DoubleEqualsInt32(0.0, &i)); MOZ_ASSERT(i == 0);
MOZ_ASSERT(DoubleEqualsInt32(-0.0, &i)); MOZ_ASSERT(i == 0);
MOZ_ASSERT(DoubleIsInt32(INT32_MIN, &i)); MOZ_ASSERT(i == INT32_MIN);
MOZ_ASSERT(DoubleIsInt32(INT32_MAX, &i)); MOZ_ASSERT(i == INT32_MAX);
MOZ_ASSERT(DoubleEqualsInt32(INT32_MIN, &i)); MOZ_ASSERT(i == INT32_MIN);
MOZ_ASSERT(DoubleEqualsInt32(INT32_MAX, &i)); MOZ_ASSERT(i == INT32_MAX);
MOZ_ASSERT(!DoubleIsInt32(0.5, &i));
MOZ_ASSERT(!DoubleIsInt32(double(INT32_MAX) + 0.1, &i));
MOZ_ASSERT(!DoubleIsInt32(double(INT32_MIN) - 0.1, &i));
MOZ_ASSERT(!DoubleIsInt32(NegativeInfinity(), &i));
MOZ_ASSERT(!DoubleIsInt32(PositiveInfinity(), &i));
MOZ_ASSERT(!DoubleIsInt32(UnspecifiedNaN(), &i));
MOZ_ASSERT(!DoubleEqualsInt32(0.5, &i));
MOZ_ASSERT(!DoubleEqualsInt32(double(INT32_MAX) + 0.1, &i));
MOZ_ASSERT(!DoubleEqualsInt32(double(INT32_MIN) - 0.1, &i));
MOZ_ASSERT(!DoubleEqualsInt32(NegativeInfinity(), &i));
MOZ_ASSERT(!DoubleEqualsInt32(PositiveInfinity(), &i));
MOZ_ASSERT(!DoubleEqualsInt32(UnspecifiedNaN(), &i));
}