2.8 Influencing runtime behavior
These options affect the runtime behavior of programs compiled with GNU Fortran.
- Specify the representation of data for unformatted files. Valid
values for conversion are: `native', the default; `swap',
swap between big- and little-endian; `big-endian', use big-endian
representation for unformatted files; `little-endian', use little-endian
representation for unformatted files.
This option has an effect only when used in the main program.
CONVERT specifier and the GFORTRAN_CONVERT_UNIT environment
variable override the default specified by -fconvert.
- Disable range checking of input values during integer
For example, GNU Fortran will give an error if an input value is
outside of the relevant range of [
HUGE()]. In other words,
INTEGER (kind=4) :: i , attempting to read -2147483648 will
give an error unless -fno-range-check is given.
- Specify the length of record markers for unformatted files.
Valid values for length are 4 and 8. Default is 4.
This is different from previous versions of gfortran,
which specified a default record marker length of 8 on most
systems. If you want to read or write files compatible
with earlier versions of gfortran, use -frecord-marker=8.
- Specify the maximum length for a subrecord. The maximum permitted
value for length is 2147483639, which is also the default. Only
really useful for use by the gfortran testsuite.
- When writing zero values, show the negative sign if the sign bit is set.
fno-sign-zero does not print the negative sign of zero values for
compatibility with F77. Default behavior is to show the negative sign.