Optimized math library on Linux AMD64

I have a problem linking with the optimized math library using Sun Studio 12 on Linux with an AMD64 processor. It complains that the pow() function depends on a missing symbol, which I believe comes from the C runtime.

This problem does not occur if I am using the regular math library, or the 32-bit optimized math library.

Any suggestions for further troubleshooting or incantations needed to remedy will be appreciated.

To reproduce the problem:

$ cat missing.f

program PowIsMissing

double precision a,b

read*,a

b=a**a

print*,b

end

$ f90 missing.f# fine

$ linux32 f90 -xlibmopt missing.f# fine, too

$ f90 -xlibmopt missing.f# native AMD64

/opt/sun/sunstudio12/prod/lib/amd64/libmopt.a(f_pow.o): In function `pow':

f_pow.c:(.text+0x7aa): undefined reference to `__xpg6'

f_pow.c:(.text+0x8e6): undefined reference to `__xpg6'

[933 byte] By [Roland_Kaufmanna] at [2007-11-27 11:41:50]