HP aC++/HP C A.06.25 Programmer's Guide

The -fast option selects a combination of optimization options for optimum execution

speed and reasonable build times. This option is equivalent to +Ofast. Currently

chosen options are:

• +O2

• +Ofltacc=relaxed

• +Onolimit

• +DSnative

• +FPD

You can override any of the options in -fast by specifying a subsequent option after

it.

Use this option when porting C++ and C applications compiled on other UNIX operating

systems to HP-UX.

NOTE: Do not use this option for programs that depend on IEEE standard

floating-point denormalized numbers. Otherwise, different numerical results may

occur.

+Ofast

The +Ofast option selects a combination of optimization options for optimum execution

speed for reasonable build times. Currently chosen options are:

• +O2

• +Ofltacc=relaxed

• +Onolimit

• +DSnative

• +FPD

• -Wl,+pi,1M

• -Wl,+pd,1M

• -Wl,+mergeseg

This option is a synonym for -fast.

NOTE: Do not use this option for programs that depend on IEEE standard floating

point denormalized numbers. Otherwise, different numerical results may occur. See

+Ofltacc=relaxed.

+Ofaster

Performance Options 93