HP Fortran Programmer's Guide (March 2010)

Migrating to HP Fortran
Incompatibilities with HP FORTRAN 77
Chapter 10230
Format field widths
HP Fortran 90 supports format field widths up to 32767. In contrast, HP FORTRAN 77 allows
format field widths up to 2147483639, which is close to 2**31.
Floating-point constants
The HP Fortran compiler differs from HP FORTRAN 77 in its handling of floating-point
constants. The HP Fortran compiler conforms to the standard: a single-precision constant is
treated as a single-precision data item in all situations, regardless of how many digits were
supplied when specifying it. HP FORTRAN 77 actually scans and saves constants internally
in double precision. This behavior can produce slightly different results.
In HP Fortran, the statement
+B +escape
-D +dlines
+es +extend_source
-F +cpp_keep
-L +list
-onetrip +onetrip
+Q +pre_include
+s
+langlvl
a
+T +fp_exception
+ttyunbuf +nottybuf
-U +uppercase
-u +implicit_none
-V
+list
a
a. Does not fully replace.
Table 10-2 f77 options replaced by f90 options (Continued)
f77 option f90 replacement