HP Fortran Programmer's Guide (September 2007)

Migrating to HP Fortran
Incompatibilities with HP FORTRAN 77
Chapter 10218
• In HP Fortran, recursive procedures must be so declared with the RECURSIVE keyword;
HP FORTRAN 77 allows recursive procedures by default.
Data types and constants
The following HP FORTRAN 77 extensions for data types and constants are not supported by
HP Fortran:
• Double precision as the default storage for floating-point constants; see “Floating-point
constants” on page 216.
• I and J integer suffixes. To express the HP FORTRAN 77 constant 10I (or I*2) in
HP Fortran, use 10_2; for 10J (or J*4), use 10_4.
• Use of the 8# n and 16# n for octal and hex constants, respectively. In HP Fortran, use O" n "
for octal constants and Z" n " for hexadecimal constants.
• BOZ constants (that is, constants in binary, octal, or hexadecimal format) in COMPLEX
expressions.
• Non-integer array bounds and character length specifiers.
• Constant expressions that contain the ** (exponentiation) operator, as in PARAMETER
(RV=1**1.2).
• Use of the PARAMETER statement without parentheses, as in
PARAMETERi=1
In free format, f90 treats this statement as an error. In fixed format, f90 treats it as an
assignment, identical to:
PARAMETERi = 1
In HP Fortran, use PARAMETER (i=1) instead.
• Use of the DATA statement to initialize integers with strings, as in:
DATA i /"abcd"/
• Use of COMPLEX(16) temporaries. For example, given the declarations:
COMPLEX(KIND=8) :: foo
REAL(KIND=16) :: bar
the expression foo**bar is legal in HP FORTRAN 77 but not in HP Fortran.
(HP FORTRAN 77 coerces COMPLEX(16) entities to COMPLEX(8) in order to continue the
computation.)
Given the previous declarations, the following is acceptable in HP Fortran:
foo**REAL(bar, 8) ! foo**bar