Hardware acceleration of Special Functions.

[Bernard]

Hi!
I would like to ask Intel's employees on this forum.Why IntelCPU architects have never implemented in hardware some of themore "popular" Special Functions like'GAMMA','BETA' and various 'BESSEL' functions of an integer order.All these functions could have been accessed byx87 ISAinstructions.

[SergeyKostrov]

Quoting bronxzv

...it was probably something like 50-100 cyclesforFP32 FMUL and FADD (based on my past experience writing FP emulation routines)...

It looks realistic. Why wouldn't we call to AMD and ask? :)

[Bernard]

think AMDusesa "Vector Table" termbecause Intel calls a similar structure as an"Interrupt Descriptor Table

It was called IVT i.e "Interrupt Vector Table" and we are talking about the DOS and 8086 CPU.
Judging by the definition of the vector as a unit composed from the number of scalars.IVT can not be called a vector nor IDT.Because these structures contain a scalar member fields which point to descriptors(in the case of IDT).

[SergeyKostrov]

Quoting iliyapolak

think AMDusesa "Vector Table" termbecause Intel calls a similar structure as an"Interrupt Descriptor Table

It was called IVT i.e "Interrupt Vector Table" and we are talking about the DOS and 8086 CPU...

Does it change an essence of interrupt or trapprocessing for Am29K microcontrollers?

[Bernard]

It is not related to AMD 29k microcontrollers.The question is why scalar member is called a vector.

[SergeyKostrov]

Quoting Sergey Kostrov

Quoting bronxzv

...it was probably something like 50-100 cyclesforFP32 FMUL and FADD (based on my past experience writing FP emulation routines)...

It looks realistic. Why wouldn't we call to AMD and ask? :)

I've sent an email to AMD and this is a core part of my e-mail:

Q:
My question is related to a legacy RISC microcontroller Am29200. The microcontroller supports 18 floating-point instructions and
all of them are emulated using traps:

How many clock cycles are needed to execute FADD or FSUB instructions?

and here is a response from AMD:

A:
AM29xxx products have not belonged to AMD since 2005. You should contact Spansion for any questions on these products:

http://www.spansion.com/support/ses/ses.html

[Bernard]

A:
AM29xxx products have not belonged to AMD since 2005. You should contact Spansion for any questions on these products

was not sure that AMD will answer your e-mail so fast.It looks like they sold their miucrocontrollers division to Spansion.

[SergeyKostrov]

Quoting iliyapolak

A:
AM29xxx products have not belonged to AMD since 2005. You should contact Spansion for any questions on these products

was not sure that AMD will answer your e-mail so fast. It looks like they sold their miucrocontrollers division to Spansion.

Intel sold a similar division ( some CPUs for embedded platforms )to Marvell.

[Bernard]

@Sergey

I think that we can come to conclusion that there is no such a thing as hardware accelerated special functions.