To clarify, there are two separate notions of division-as-multiplication discussed here.
Modular division is straightforward to convert to a multiplication; however this is mainly for specialized applications, like cryptography and number theory. It's uncommon to want divide-by-2 to make the value larger.
Ordinary flooring division can also be converted to a multiplication problem when the dividend is bounded. This uses the "magic number" approach where you multiply by a rounded scaled reciprocal, and then do some work to correct the error from rounding.
Comments
To clarify, there are two separate notions of division-as-multiplication discussed here.
Modular division is straightforward to convert to a multiplication; however this is mainly for specialized applications, like cryptography and number theory. It's uncommon to want divide-by-2 to make the value larger.
Ordinary flooring division can also be converted to a multiplication problem when the dividend is bounded. This uses the "magic number" approach where you multiply by a rounded scaled reciprocal, and then do some work to correct the error from rounding.