🚀 go-pugleaf

In <3D0B57CB.5060406@nospam.com>, Hugh wrote:

Your reference to "special features" is not very specific.

For GCC 3.1, the release notes say (
http://gcc.gnu.org/gcc-3.1/changes.html )

*********************************
* The compiler now supports MMX, 3DNow!, SSE, and SSE2 instructions. 
Options -mmmx, -m3dnow, -msse, and -msse2 will enable the respective 
instruction sets. Intel C++ compatible MMX/3DNow!/SSE intrinsics are 
implemented. SSE2 intrinsics will be added in next major release.

* Following those improvements, targets for Pentium MMX, K6-2, K6-3, 
Pentium III, Pentium 4, and Athlon 4 Mobile/XP/MP were added. 
Refer to the documentation on -march= and -mcpu= options for details.
*******************************************************************

Note that the Athlon supports MMX and the Athlong XP supports SSE.

In the case of latex and a large document though, I'm not sure that
the newer instructions could play a big role.   The problem for Pentium 4
is probably that there is a lot of branching, probably
a large working set (number of different active pages in memory on
avg.), and frequent I/O operations.  One expects the Pentium 4 to 
be strong in situations where there are big vectors to process
deterministically, and in these cases, the compiler opimizations
play a big role.


-= Josh


> The following is my general finding so far:
> 
> Special features of Pentium 4 cpu is not generally utilized by
> gcc-2.95.** which is used for most Linux distributions rpms. Latexing a
> big document with Zeon Pentium 4 at 1.7GHz (52 sec) is actually even
> slower than Pentium III running at 700MHz giving 35 sec.
> 
> On Athlon at 1.6GHz, it gives 16 sec.  The best.
> 
> Is my understanding for the reason of slow speed with P4 correct?
> gcc-2.95.  If I do obtain te-latex.src.rpm and then compile it with
> gcc-3.1, would I get much faster binary under Pentium 4?
> 
> The problem with Pentium 4 is not just limited with Latex. I in fact
> hate Pentium 4, because I simply believed in their high SPEC rating, and
> bought a bunch of Pentium 4 Xeon duals only to find out that the even
> the Fortran speed (with their Intel compiler) is in fact dismal.
> 
> Regards,
> 
> Hugh