[music-dsp] fixed point? floating point? MAC?

[Russell Borogove]

Nigel Redmon wrote:
> > What's all this talk about MACs?  Isn't that made by Apple?
> 
> To elaborate on Bram's answer, it's a single instruction that 
> multiplies two number and adds them to the accumulator.

And to elaborate on your elaboration, many DSPs have a 
MAC instruction with the properties you describe and 
many general-purpose CPUs don't. 

Besides audio DSP purposes, multiply-and-accumulate is 
also key to matrix math, which means it's key to 3D math,
which makes it interesting for game platforms. The Hitachi 
SH4, used in the dearly departed Sega Dreamcast game 
console, had vector registers and MAC instructions. I
believe the PS2 does as well, in one of its dark and 
twisty processing units, all different.

-Borogove