On 04/07/2011 08:36 AM, Paul Kapinos wrote:
Hi Terry,


so, the attached ceil.c example file *can* be compiled by "CC" (the Studio C++ compiler), but *cannot* be compiled using "cc" (the Studio C compiler).
$ CC ceil.c
$ cc ceil.c

Did you try to link in the math library -lm?  When I did this your test program worked for me and that actually is the first test that the configure does.

5. Looking into configure.log and searching on `ceil' results: there was a check for the availability of `ceil' for the C compiler (see config.log.ceil). This check says `ceil' is *available* for the "cc" Compiler, which is *wrong*, cf. (4).
See above, it actually is right when you link in the math lib.

Thankt for the tipp! Yes, if using -lm so the Studio C compiler "cc" works also fine for ceil.c:

$ cc ceil.c -lm



So, is there an error in the configure stage? Or either the checks in config.log.ceil does not rely on the avilability of the `ceil' funcion in the C compiler?
It looks to me like the lbat configure test is not linking in the math lib.

Yes, the is no -lm in configure:84213 line.

Note the cheks for ceil again, config.log.ceil. As far as I unterstood these logs, the checks for ceil and for the need of -lm deliver wrong results:


configure:55000: checking if we need -lm for ceil
....
configure:55104: result: no

configure:55115: checking for ceil
....
configure:55115: result: yes


So, configure assumes "ceil" is available for  the "cc" compiler without the need for -lm flag - and this is *wrong*, "cc" need -lm.

Interesting.  I've looked at some of my x86, Studio, linux builds of OMPI 1.5 branch and I see the correct configure results for ceil that correctly identify the need for -lm.  Your's definitely does not come up with the right answer.  Are you using the "official" ompi 1.5.3 tarball? 
It seem for me to be an configure issue.

Certainly does.

--
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Terry D. Dontje | Principal Software Engineer
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