That's fair but mod is division, or no? So realistically the new magic number version would be faster. Assuming there is 32 bit int support. Sorry, this is above my paygrade.
Many compiles will compute div-by-a-constant using the invert, multiply, and shift off the remainder trick. Once you have that, you can do mod-by-a-constant as a derivative and usually still beat 1-bit or 2-bit division.
Yeah, I'm thinking more of ones that remove all the divs from some crazy math functions for graphics rendering and replace them all with bit shifts or boolean ops.
That's fair but mod is division, or no? So realistically the new magic number version would be faster. Assuming there is 32 bit int support. Sorry, this is above my paygrade.
Many compiles will compute div-by-a-constant using the invert, multiply, and shift off the remainder trick. Once you have that, you can do mod-by-a-constant as a derivative and usually still beat 1-bit or 2-bit division.
Division still is worse:
https://github.com/ridiculousfish/libdivide
Yeah, I'm thinking more of ones that remove all the divs from some crazy math functions for graphics rendering and replace them all with bit shifts or boolean ops.