Function mul_safe

Source/astcenc_mathlib.h:493–501

* @brief Compute the product of two sizes. * * This function is implemented to indicate if overflow has occurred, which may * occur when input values are not trusted. Implementation is obviously slower * than one that does not do this, so don't use for values we know cannot * overflow. * * Overflow signaling is sticky, so calling code can check at the end of a * sequence of multiplies. *

 * @return The multiplication result, which may have overflowed.
 */
static inline size_t mul_safe(
	size_t val_a,
	size_t val_b,
	bool& overflow
) {
	size_t result = val_a * val_b;
	overflow = overflow || ((val_b != 0) && ((result / val_b) != val_a));
	return result;
}

/**
 * @brief Get the number of blocks along a single axis.