HP aC++/HP C A.06.20 Programmer's Guide

The +FP option specifies how the runtime environment for floating-point operations
should be initialized at program startup and used at link time. The default is that all
trapping behaviors are disabled.
The following flags are supported. Uppercase enables the flag, lowercase disables the
flag.
Table 2-3 Options for +FP[flags]
DescriptionFlag
Trap on invalid floating-point operations.
V (v)
Trap on divide by zero.
Z (z)
Trap on floating-point overflow.
O (o)
Trap on floating-point underflow.
U (u)
Trap on floating-point operations that produce inexact results.
I (i)
Enable sudden underflow (flush to zero) of denormalized values.
D (d)
To dynamically change these settings at runtime, see fesetenv(3M).
+FPmode
+FPmode specifies how the run-time environment for floating-point operations should
be initialized at program start up. By default, modes are aas specified in the IEEE
floating-point standard: all traps disabled, gradual underflow, and rounding to nearest.
See ld(1) for specific values of mode. To dynamically change these settings at run
time, refer to fenv(5), fesettrapenable(3M), and fesetround(3M).
+O[no]libmerrno
+O[no]libmerrno
Description:
The +O[no]libmerrno option enables [disables] support for errno in libm functions.
The default is +Onolibmerrno for C++, c99, or —AC99.
In C-mode, the default is +Olibmerrno with -Aa option.
+Oprefetch_latency
+Oprefetch_latency=cycles
The +Oprefetch_latency option applies to loops for which the compiler generates
data prefetch instructions. cycles represents the number of cycles for a data cache
miss. For a given loop, the compiler divides cycles by the estimated loop length to
arrive at the number of loop iterations for which to generate advanced prefetches.
Floating-Point Processing Options 53