Changing mathlibs is it really usefull?

[Gulliver]

Hi, i ´ve got a question, from all those math libs replacements out there I want to know how often are they used by workbench and applications? Do any of you know?

Thanks

[SilvrDrgn]

I would bet that math libs are not used by Workbench too much unless you have some fancy icon system installed. They are used a lot by graphics intensive programs like browsers, paint apps and image processors.  I have HSMathLibs on my A4000T.  The speedup from the standard math libs is very noticeable.

[dannyp1]

I also bought the HighSpeedMathLibs and have never regretted it.  

Dan

[Tenacious]

IIRC, the math libraries are used in machines without math co-processors (68881 and 68882).  I don't believe Workbench's GUI requires much number crunching.  Applications like Digital Universe, Distant Suns, Vista Pro, ray tracers, etc are performance-dependent upon the quality of the libraries or co-processor.

It seems back in my A500 days, some of the enhansed and optimized math libraries on Aminet made a noticable difference.

[Gulliver]

Okay, so then i will parobably think on actually registering hs-mathlibs for my 68040 Amiga.
Thanks

[matthey]

@Gulliver

Often the fpu instructions are put directly in the code. In that case, having fast math libraries will offer no speed increase. There are plenty of cases where the math libraries are used though and the C= versions arer not very optimized.

[Tenacious]

Someone will correct me if I'm wrong.  The 68040 and 68060 CPUs have FPUs (math co-processor) built into their chip.  The 68020 and 68030 were designed to be supplimented by a seperate math co-processor (68881 or 68882), or, could run the libraries.

The 68000 and 68010 are compatible with math co-processors, I think, but were never expected to have FPUs available.  I think code for these CPUs usually require the libraries.

[SamuraiCrow]

The '040 and '060 only have partial FPUs built in.  You still need an external FPU for the full-functionality.  However, 68881/2 FPUs aren't pipelined and therefore aren't very fast.

[matthey]

@SamuraiCrow

There is no external "hardware" fpu. There is a software emulation of the unavailable 68881/68882 instructions that are unavailable in the 68040 and 68060. These are in the 68040.library and 68060.library respectivly. The cpu traps the unavailable older fpu instructions which is slow. They are still generally faster than the 68881/68882 on newer processors even when trapped. Unfortunatly, going through the cpu traps is slow compared to using only the fpu instructions that are built in. There is Oxypatcher type programs to speed up older programs that use 68881/68882 instructions on the 68040 and 68060. Oxypatcher type programs offer a speed increase if...

You have a 68040 or 68060.
You have programs that use the fpu directly instead of the math libraries.
The programs are NOT compiled for 68040 or 68060.

Faster math libraries offer a speed increase if...

The math libraries are used instead of the fpu directly.

[SamuraiCrow]

Ok, my bad.