Chad Perrin wrote:
> Bryan J. Smith wrote:
>
>> On Mon, 2004-10-11 at 02:49, Robert Snyder wrote:
>>
>>> I dont see it passing any -O3 commands to the compilier. As I watch it
>>> go passing by.
>>> The defualt cflags for Portage when compiling are "-O2 -march=pentium4
>>> -fomit-frame-pointer" Now I have noticed when using a gui front end
>>> like
>>> porthole that at the bottom they do list additional flags that the
>>> piticular ports mantainer decided to use extra usually you see thing
>>> like mmx and sse flags but never seen the -O3
>>
>>
>>
>> Okay, maybe the package offers SSE support.
>>
>> That's fine for gaming, but for scientific/engineering, do _not_ use SSE
>> on a Pentium 3/4! Trust me on this.
>>
>>
>>> But things are stable and "FEEL" slightly faster. I will emphansize
>>> "FEEL" because I have no hard proof that it is faster.
>>
>>
>>
>> If SSE is being liberally used where it shouldn't, which I've seen a few
>> packages do not, then I don't doubt it.
>>
>> You should _never_ use SSE for double-precision floating-point on a
>> Pentium 3/4 when you need accuracy. It's lossy and inaccurate by a
>> significant number of digits.
>>
>> The P3/4 SSE pipes were designed to be fast, not accurate.
>> Most people don't know this until they get major error in a calculation.
>>
>
> I'm probably opening a can of worms I shouldn't by asking this, but:
>
> What is SSE? I know what the FPU is, but you lost me with SSE.
SSE is Streaming SIMD Extensions and what are Streaming SIMD Extensions
- Intel Corporation
<http://computing-dictionary.thefreedictionary.com/Intel%20Corporation>'s
floating point SIMD
<http://computing-dictionary.thefreedictionary.com/SIMD> extention of
their Pentium
<http://computing-dictionary.thefreedictionary.com/Pentium>
microprocessor
<http://computing-dictionary.thefreedictionary.com/microprocessor>
architecture. SSE was formerly know as KNI (Katmai New Instructions). It
was introduced with the Pentium III
<http://computing-dictionary.thefreedictionary.com/Pentium%20III>.
SSE was to help video and audio applications ( does this sound filimiar
yet) Long story short best way to describe the functions of SSE is to
say it took over for MMX..... While it more than simply MMX2 it tooks
expanded on MMX and supposely the MMX2 project got merged into SSE and SSE2
*SSE-2* - Intel Corporation
<http://computing-dictionary.thefreedictionary.com/Intel%20Corporation>'s
extention of their SSE
<http://computing-dictionary.thefreedictionary.com/SSE> floating point
SIMD <http://computing-dictionary.thefreedictionary.com/SIMD>
instructions to handle 64-bit floating point numbers. SSE-2 was
introduced with the Pentium 4.
*Matrix Math eXtensions* - (MMX) (NOT an acronym for "MultiMedia
eXtension", according to Intel, but an Intel brand name) A set of 57
extra instructions built into some versions of Intel's Pentium
<http://computing-dictionary.thefreedictionary.com/Pentium>
microprocessors for supporting SIMD
<http://computing-dictionary.thefreedictionary.com/SIMD> operations on
multimedia
<http://computing-dictionary.thefreedictionary.com/multimedia> and
communications data types.
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