HP Fortran Programmer's Guide (March 2010)

Compiling and linking
Compiling with the f90 command
Chapter 240
sudden underflow available, while others do not. The +FPD option enables
the hardware to flush denormalized values to zero, but it does not require
that it do so.
Table 2-4 Values for the +FP option
Value Meaning
V Trap on invalid floating-point operations. Examples of
invalid floating-point operations include the following:
• Arithmetic operation on NaNs
• Operations such as (+inf) + (-inf) and (+inf) -
(+inf)
• Multiplication of 0 and infinity
• Division operations 0/0 and inf/inf
• Certain floating-point remainder operations
• Square root of a negative value
• Certain kinds of comparisons of unordered values
Z Trap on floating-point divide by zero.
O Trap on floating-point overflow.
U Trap on floating-point underflow.
I Trap on floating-point operations that produce inexact
results. Inexact result traps may occur whenever roundoff
is necessary to produce the result. For example, the fraction
1.0/3.0 produces an inexact trap because there is no exact
floating-point representation for this fraction.