On Sat, 5 Mar 2011, Dr. David Kirkby wrote:
On 03/ 4/11 11:40 PM, luke-tier...@uiowa.edu wrote:
On Fri, 4 Mar 2011, Dr. David Kirkby wrote:
The R manual says R will not build with gcc on 64-bit Solaris x86 with
gcc
http://cran.r-project.org/doc/manuals/R-admin.html#Solaris
"Tests with gcc32 on ‘x86’ and ‘amd64’ have been less successful:
‘x86’ builds have failed on tests using complex arithmetic33, whereas
on ‘amd64’ the builds have failed to complete in several different
ways, most recently with relocation errors for libRblas.so. "
I know what the "relocation errors" problem is. That library (and in
fact two other R libraries) all have non-PIC code in them, despite the
fact the source is compiled with the -fPIC option.
http://blogs.sun.com/rie/entry/my_relocations_don_t_fit
shows how to prove this. If one runs this command on Solaris:
$ elfdump -d libRblas.so | fgrep TEXTREL
there is some output showing that theres non-PIC code present in the R
library.
R is compiled with -fPIC on Solaris, but certain things can cause
non-PIC code to be generated even with that option. One is by the use
of "computed gotos" which is a gcc extension. I'm wondering if R uses
any of these.
Yes -- in the byte code interpreter in eval.c
luke
Thank you Luke. Do you know if there may be any others?
I do not.
Do you know if that bit of code gets compiled into all 3 of the R libraries?
I tried replacing
I do not know
#define NEXT() (__extension__ ({goto *(*pc++).v;}))
by a function which did absolutely nothing. The code built, but still had the
library issues.
I'm almost certain that the definition of NEXT will cause problems, but I'm
not convinced it is the only issue.
What happens if a non-GNU compiler is used? I assume these GNU extensions
don't get used, so how comes the code builds? Is there any way I can disable
the use of the GNU extensions, while still building with gcc.
This particular bit It only uses the gcc extensions for gcc compilers,
and this can be turned off by defining NO_THREADED_CODE.
It is rather annoying that the code has __extension__ in it, which disables
the warnings about the use of GCC extensions.
http://gcc.gnu.org/onlinedocs/gcc/Alternate-Keywords.html
Why is there a need to hide the use of the extensions?
To avoid spurious warnings
I'd personally like to
see just standard C used, without any extensions. Then problems like I'm
having would be less likely to occur.
This extention is very useful for implementing byte code interpreters,
which is why it is being used. As mentioned above, its use can be
turned off.
luke
--
Luke Tierney
Statistics and Actuarial Science
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa Phone: 319-335-3386
Department of Statistics and Fax: 319-335-3017
Actuarial Science
241 Schaeffer Hall email: l...@stat.uiowa.edu
Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
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