Problems with 2.3.5b -> Makedev, Compiler Ops and Bash Problem

Simon Perreault nomis80 at videotron.ca
Wed Jun 21 12:43:21 PDT 2000


> BTW: Please could someone explain more about the compiler optimizations?:
> a) I have an Intel Celeron CPU....is i686 right?
> b) Has anyone built a full LFS system with them?
> - Does it all build with these env variables set?
> - Does it make it any faster?
> c) Instead of make in the book, do I need to do:  make -e  ?
> - is that all I have to do?

a) it depends on the celeron. If I'm right (and I may very well not be) the
celeron up from 300A are based on pentium pro, and the celeron below 300A
(that includes the 300) are not, so they should be 586.

b) I have built a full LFS system with PGCC (pentium GCC). It's a patch for
GCC that enables advanced optimization features. See www.goof.com/pcg for
more info. I have always used "-O6 -mcpu=k6 -march=k6" except for bash,
because it seems very badly coded/sensitive to optimization, and everything
is working right (except vim, it does a segfaulting when I press "dd", so
I'll remake it without optimization). The most notable speed improvement
i've seen is with gzip. It's a LOT faster (the folks at PGCC claim a 30%
speed increase). Anyway, all the progs on LFS do not use the processor
extensively. A speed improvement would be noticed with programs like X or an
mp3 player, a ray tracer or something else for which the cpu is the
bottleneck.

c) Gerard should read this too: when your CFLAGS and CXXFLAGS are set, and
you ./configure a program, the configure script automatically adds the
CFLAGS and CXXFLAGS env variables to the Makefile, so make -e is not
necessary (in fact, it would be bad to use make -e since it overrides flags
used in the Makefile, and it could cause compilation problems). When a
configure script is not used, I always edited the Makefile manually, and the
CFLAGS variable was easily modifiable. I have never used make -e, as I
feared compilation problems. So my suggestion is to simply remove all the
make -e and specify that the CFLAGS and CXXFLAGS should be set in
.bash_profile and that the configure scripts automatically use them. BTW, I'
ve always wondered what was the purpose of those -e in the static compiling
part.


This, as usual, was only my newbie advice.


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