bool
SCInput::readDouble(double *p)
{
union {
uint64_t u;
double d;
} pun;
if (!read(&pun.u))
return false;
*p = CanonicalizeNaN(pun.d);
return true;
}
Value
SharedTypedArrayObjectTemplate<double>::getIndexValue(JSObject *tarray, uint32_t index)
{
double val = getIndex(tarray, index);
/*
* Doubles in typed arrays could be typed-punned arrays of integers. This
* could allow user code to break the engine-wide invariant that only
* canonical nans are stored into jsvals, which means user code could
* confuse the engine into interpreting a double-typed jsval as an
* object-typed jsval.
*/
return DoubleValue(CanonicalizeNaN(val));
}
Value
SharedTypedArrayObjectTemplate<float>::getIndexValue(JSObject *tarray, uint32_t index)
{
float val = getIndex(tarray, index);
double dval = val;
/*
* Doubles in typed arrays could be typed-punned arrays of integers. This
* could allow user code to break the engine-wide invariant that only
* canonical nans are stored into jsvals, which means user code could
* confuse the engine into interpreting a double-typed jsval as an
* object-typed jsval.
*
* This could be removed for platforms/compilers known to convert a 32-bit
* non-canonical nan to a 64-bit canonical nan.
*/
return DoubleValue(CanonicalizeNaN(dval));
}
bool
SCOutput::writeDouble(double d)
{
return write(ReinterpretDoubleAsUInt64(CanonicalizeNaN(d)));
}