gbadev.org forum archive

This is a read-only mirror of the content originally found on forum.gbadev.org (now offline), salvaged from Wayback machine copies. A new forum can be found here.

Coding > Floating point?

#21798 - Abscissa - Sun Jun 06, 2004 2:06 am

Does anyone know how good the GBA's floating point is? I remember back in the days of DOS games anything that needed a fractional portion was usually just done with "fixed-point" math since the floating point on pre-Pentium CPU's was so slow. I'm relatively new to GBA dev (most of my programming has been on x86), so is this someting that's usually done on the GBA, or does the ARM have floating point that's good enough that I can avoid all of the fixed-point tricks?

Nick

#21799 - tepples - Sun Jun 06, 2004 2:49 am

Like Intel's 386 and 486SX CPUs, the ARM7TDMI CPU in the GBA lacks a dedicated floating-point coprocessor, meaning that the CPU has to emulate it. You'll need to use fixed-point arithmetic if you want any semblance of speed.
_________________
-- Where is he?
-- Who?
-- You know, the human.
-- I think he moved to Tilwick.

#21801 - Abscissa - Sun Jun 06, 2004 4:04 pm

Ok, cool. Heh, it's amazing just how much GBA development resembles the old DOS game development. I think that's why I like it so much :)