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

+wlock
+wlock
The +wlock option enables compile-time diagnostic messages for potential errors in
using lock/unlock calls in programs that use pthread-library-based lock/unlock functions.
Warnings are emitted for acquiring an already acquired lock, releasing an already
released lock, and unconditionally releasing a lock that has been conditionally acquired.
This diagnostic checking is based on cross-module analysis performed by the compiler.
Therefore, the +wlockoption implicitly enables a limited form of cross-module analysis,
even if -ipo or+O4 options are not specified. This can lead to a significant increase in
the compile time compared to a build without the +wlock option. Using this option
could result in the compiler invoking optimizations other than those that are part of
the user-specified optimization level. If +wlock is used in addition to -ipo or +O4,
the generated code is not affected, and the compile time does not increase much.
Performance Options
The HP compiler provides a variety of options to help improve build and runtime
performance. These options are:
-fast
-fast
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
+Ofast
Performance Options 91