HP Fortran v 3.0 Release Notes

HP Fortran Release Notes

Known Problems and Workarounds

Chapter 1 7

• When creating 64-bit shared executables (such as when +DD64 is speciﬁed) the +Z option

is on by default. The +Z option (equivalent to +pic=long) is the only PIC option supported

for 64-bit executables. If the +z option (equivalent to +pic=short) is speciﬁed when

creating 64-bit code, it instead maps to +Z.

Workaround: To not generate position independent code for 64-bit executables, specify

the following option:

-Wl,-noshared

• Mixing the standard Fortran I/O operations with BUFFER IN and BUFFER OUT I/O on the

same logical unit number can confuse the input stream (READ) or corrupt the data ﬁle

(WRITE).

• SoftBench support is not available.

• Using the ON statement at optimization levels 2 and above is restricted. When compiling

at optimization level 2 or above, the optimizer makes assumptions about the program that

do not take into account the behavior of procedures called by the ON statement. Such

procedures must therefore be “well-behaved”; they must meet the following criteria:

— The ON procedure must not assume that any variable in the interrupted procedure or

in its caller has its current value. (The optimizer may have placed the variable in a

complete.)

— The ON procedure must not change the value of any variable in the interrupted

procedure or in its caller if the effect of the ON procedure is to return program control

to the point of interrupt.

NOTE These restrictions do not apply if you compile at optimization levels +O0

and +O1.

• The +DS compile-line options do not accept any PA-RISC architecture models as

arguments because the HP Fortran compiler for Itanium-based architectures does not

support the PA-RISC architecture.

• Pointer arithmetic on Cray-style pointers has different semantics on Hewlett-Packard

machines than on some Cray machines. HP Fortran implements Cray pointers as BYTE

pointers, while some Cray machines use word addressing.

• Large source ﬁles occasionally cause internal errors in the HP Fortran compiler.

Workaround: If this occurs, split the ﬁle using fsplit and recompile.

• The previous versions of Fortran occasionally contained a 'wrong answer' problem that is

now caught by a compiler assert function at +O3 +Oparallel.