ABI mismatch for single precision floating point return between C and Fortran

[Gerhard Tonn <GerhardTonn at swol dot de>]

Hi,
when I compile and link the following two small programs on the S/390 
architecture, I get a wrong result from the C function. This is caused by the 
fact that according to the ABI on S/390 a float is returned as single 
precision float, but Fortran expects that it is returned as double (that is 
what the assembler says).

Does anyone know, if this is somehow tied to Fortran or if I can change this 
behaviour by any backend switches. The problem occurs with 2.95.4, 3.0.4 and 
the latest 3.1 snapshot.

Btw, the same problem seems to appear on sparc.

Thanks in advance
Gerhard


      PROGRAM         TST
*     .. Parameters ..
      INTEGER         NOUT
      PARAMETER       (NOUT=6)
      REAL            EC
*     .. External Subroutines ..
      EXTERNAL        SDOTTESTC


      EC=SDOTTESTC()

      WRITE (NOUT,99997) EC
      RETURN
99997 FORMAT(2E12.4)
      END

float
sdottestc_()
{
  float e = 1.34;
  printf("%e\n", e);
  return e;
}