[R] switching to Linux, suggestions?

[Peter Dalgaard]

lederer at trium.de writes:

> D) R 1.9.0-r1 under Gentoo, using the CFLAGS for the whole system,
> not just for R.
>                  benchmark cpu.user cpu.system
> 1        benchmark.density   176.08       6.10
> 11      benchmark.survival    84.20       0.14
> 12 benchmark.linearalgebra   134.72       6.54
> 
> My CFLAGS (for a centrino) are:
> CFLAGS="-pipe -O3 -march=pentium4 -mmmx -msse -msse2 -mfpmath=sse,387
> -maccumulate-outgoing-args -mno-align-stringops -fomit-frame-pointer
> -ffast-math -fsched-spec-load -fprefetch-loop-arrays -ftracer
> -fmove-all-movables"
> 
> Question to the Gurus: Would it be allowed, to use
> -funsafe-math-optimizations?

Not if you want R to pass its own selftests....

Notice also that for linear algebra, the use of an optimized blas
(Goto, ATLAS) will have a much stronger influence than compiler
options. 

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907