Faster Square Roots

[boriel]

My floating point Square rooot routine (Function SQRT in the above code) is written so that it can replace sqrt.asm in the library.asm folder. It uses the ROM calculator too - but it doesn't call the SQR routine in it because it's really slow! It uses the calculator in a way that the ROM should have. It's at least triple the speed of the original, for a handful of bytes. Some modified ROMs use this method, I understand. I designed that function so it should plug straight in to your sqrt.asm file directly. It even calls the calculator stack routine you have.

By my count your version is 9 bytes, and my version is just 47 bytes. Probably not too big a sacrifice for the speed. Especially if it's not included if SQR isn't used.

My recommendation is to adopt my floating point one as the standard for the compiler, and have integer as a #include option. Though we probably need one that works with LONG data type as well.

I 47bytes can be really much! But I was thinking in an alternative solution. By using a --fast-float flag, this and other alternatives floating points routines will be uses in place of the standard ones. This could be easily acomplished by adding an #ifdef ... in the libasm/sqrt.asm file ;-)