HP-UX Floating-Point Guide

Chapter 1 27
Introduction
Overview of HP-UX Math Libraries
The uts.release is the release of HP-UX on the system where you run
the program. The _SYSTEM_ID is the kind of code the compiler
generated. The _CPU_REVISION is the architecture type.
If you compile this program on a PA1.1 system, then run it on a PA2.0
system running HP-UX Release 11.0, you get results like the following:
Release = B.11.00
_SYSTEM_ID = 210
_CPU_REVISION = 214
The release, 11.00, is easy to decipher. To decode the other results, search
the file /usr/include/sys/unistd.h:
$ grep 210 /usr/include/sys/unistd.h
# define CPU_PA_RISC1_1 0x210 /* HP PA-RISC1.1 */
$ grep 214 /usr/include/sys/unistd.h
/# define CPU_PA_RISC2_0 0x214 /* HP PA-RISC2.0 */
The compiler generated PA1.1 code, which is running on a PA2.0 system.
Selecting Different Versions of the Math
Libraries
If you use a compilation command (f90, cc, and so on) to invoke the link
editor (ld), the selection of math libraries is driven by the +DA compiler
option.
By default, the compiler generates code for the kind of system on which
you are running the compiler. This ensures the best possible performance
on that system. If you compile on a PA2.0 system, by default the compiler
generates narrow-mode code.
Table 1-2 describes the code-generation compiler options.