[Pfspd-users@sf.net] Cpfspd speed optimization on cygwin

[Bram R. <bra...@ph...>]

Hi all,

Today, I updated the cpfspd_fio.c module in the code repository.
This code contains a speed optimized memcpy function, that uses
assembly and intrinsics for cpu identification, data prefetching and
fast copy using the SSE instruction set.
Uptil now, this is available on the win32 platform only; not on cygwin.
This assembly code has been streamlined for a few % more
performance (hence lower cpu load for file access functions).

Furthermore, I prepared gcc compilation for this code.
Unfortunately it requires the -mpentium4 compiler flag.
So, even though the cpu is checked at runtime whether the optimized
code can be executed, I cannot compile it unless the processor is
specified to the compiler.
I am reluctant to specify the  -mpentium4 flag because I don't know
what the compiler will do with all other code...
I do not want to distribute a cpfspd library that fails on older 
(pre-pentium4)
systems. And I do not have such systems to test...
Therefore, the optimized memcpy code is still not activated on cygwin.

Any suggestions? Opinions? Hints to compile without the processor flag?

Regards, Bram.

--
A.K. (Bram) Riemens
Principal Scientist, DSP group, Philips Research
Office: WO-p-94, Postbox WO02
High Tech Campus 36 (WO), 5656 AE Eindhoven, The Netherlands
Tel: +31 40 27 43833, Fax: +31 40 27 44675
E-mail: bra...@ph...