Double complex with gcc and Intel v9 Fortran (PR#8699)

Full_Name: Christian Marquardt
Version: 2.2.1
OS: Linux
Submission from: (NULL) (84.167.229.240)


Hello,

I believe this is a bug in the configuration / installation:

When configuring R-2.2.1 using the Intel v9 Fortran compiler as default 
Fortran compiler and g++ as C++ compiler on a Suse 9.3 Linux, the 
configuration script finds that the C and Fortran idea of double comples 
disagree.

I have tried to extract the test used for this from m4/R.m4 (a slightly 
modified version of the two test files is added at the end). When 
compiling

  ifort -c ctest.f
  gcc -c cftest.c

and linking properly,

  ifort -nofor_main cftest.o ctest.o -o runme

running the executable gives the following output:

  ./runme
123.456000 14.710644
0.000000 -0.000006

To me, this inicates that the test should actually be passed successfully.

Unfortunately, I haven't quite understood how to rebuild the configure.ac etc
once R.m4 is changed;

otherwise I would try to come up with a patch for R.m4.
But maybe someone else can fix this?

Many thanks,

 Christian.


----<ctest.f>------------------------------------
     subroutine cftest(x)
     complex*16 x(3)
     integer i

c a few tests of constructs that are sometimes missing
     if(x(1) .eq. x(1)) i = 0
     x(1) = x(1)*x(2) + x(3)
     end

----<cftest.c>------------------------------------
#include <math.h>
#define HAVE_F77_UNDERSCORE 1
#ifdef HAVE_F77_UNDERSCORE
# define F77_SYMBOL(x)   x ## _
#else
# define F77_SYMBOL(x)   x
#endif

typedef struct {
       double r;
       double i;
} Rcomplex;

extern void F77_SYMBOL(cftest)(Rcomplex *x);

int main () {
   Rcomplex z[3];

   z[0].r = 3.14159265;
   z[0].i = 2.172;
   z[1].i = 3.14159265;
   z[1].r = 2.172;
   z[2].r = 123.456;
   z[2].i = 0.123456;
   F77_SYMBOL(cftest)(z);
   printf("%f %f\n", z[0].r, z[0].i);
   printf("%f %f\n", z[0].r - 123.456, z[0].i - 14.71065);
   if(fabs(z[0].r - 123.456) < 1e-4 && fabs(z[0].i - 14.71065) < 1e-4)
       exit(0);
   else exit(1);
}