[Rd] -malign-double
Paul Gilbert
gilb@home.com
Wed, 28 Feb 2001 10:43:19 -0500
I was just looking at the documentation for g77 and noticed the
following, and also noticed that it is not used when fortran for a
package is compiled with the default (i.e. no Makefile in src
directory.) Should it be considered?
Paul Gilbert
_____
`-malign-double'
(Intel x86 architecture only.)
Noticeably improves performance of `g77' programs making heavy use
of `REAL(KIND=2)' (`DOUBLE PRECISION') data on some systems. In
particular, systems using Pentium, Pentium Pro, 586, and 686
implementations of the i386 architecture execute programs faster
when `REAL(KIND=2)' (`DOUBLE PRECISION') data are aligned on
64-bit boundaries in memory.
This option can, at least, make benchmark results more consistent
across various system configurations, versions of the program, and
data sets.
*Note:* The warning in the `gcc' documentation about this option
does not apply, generally speaking, to Fortran code compiled by
`g77'.
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !) To: r-devel-request@stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._