Rob Leslie wrote:
In addition to what Andre says in his message (below), it wouldn't hurt to add a PPC assembly version of the FPM fixed-point multiply routines.
Actually, the compiler does such a good job, I don't think we need anything special on PowerPC. In 32-bit mode, the PowerPC has a 32x32 -> 64 bit multiply cabability. It uses two instructions (hi/low) and two destination registers. The C-code is optimized right into what I would write for an inline function. I have looked at the output from the IMDCTs and I don't think I can improve on that with any assembler either.
.... Probably you're using the FPM_APPROX version now,
Yes, that is what I was using. Unfortunately, the FPM_64BIT blows my CPU budget on the baby processor, but it is close. I can crank up the PLL and probably get a little more with some profiling.
I am finding bugs in the compiler with the multi-dimensional arrays and in 'make', so I need to correct these as well.
I'll keep you posted on any improvements I make.
Thanks for the great starting point!
-- Dan