CLSG607DAL Users' Note - License Managed

NAG C Library, Mark 7

CLSG607DAL - License Managed

Silicon Graphics (IRIX 6)

Users' Note

1. Introduction

This document is essential reading for every user of the NAG C Library Implementation specified in the title. It provides implementation-specific detail that augments the information provided in the NAG C Library Manual and Introductory Guide. Wherever those manuals refer to the "Users' Note for your implementation", you should consult this note.

In addition, NAG recommends that before calling any library routine you should read the following reference material (see Section 5):

(a) Essential Introduction
(b) Chapter Introduction
(c) Function Document

2. Availability of Functions

All functions listed in the chapter contents documents of the NAG C Library Manual, Mark 7 are available in this implementation. At Mark 7, 397 new primary ("user-callable") functions have been introduced. Please consult Mark 7 News (see Section 5) for lists of these functions and for a list of functions scheduled for withdrawal at future Marks. Your suggestions for new algorithms for future releases of the Library are welcomed (see Section 7).

3. General Information

This implementation includes libraries in both archive and dynamic share object (DSO) forms for the following combinations of Application Binary Interfaces (ABI) and Instruction Set Architectures (ISA):

high performance 32-bit (-n32) mode using -mips3
high performance 32-bit (-n32) mode using -mips4
64-bit mode using -mips3
64-bit mode using -mips4

3.1. Accessing the Library

Assuming that the symbolic links for libnagc.a and libnagc.so have been created in the appropriate system library directories which appear in the search path of the linker and that the NAG include files have been moved to /usr/include, then you may link to the shareable NAG C Library for ABI (here -n32) and ISA (here -mips4) in the following manner:

cc driver.c -n32 -mips4 -lnagc -lpthread -lm

where driver.c is your application program.

The specific library used by the linker depends on the compilation options, if any, specified by the user and also on the system processor. On systems such as the Silicon Graphics Power Indigo2, based on a R8000 processor, the default is 64-bit and MIPS IV whereas on systems such as the Silicon Graphics Origin 3400, based on a R12000 processor, the default is high performance 32-bit (-n32) and MIPS IV. These defaults can be changed by setting various environment variables (see man pe_environ).

The choice of the libraries linked can also be controlled by specifying the appropriate compiler options for ABI (-n32 or -64) and ISA (-mips3 or -mips4).

It may also be necessary to append the location of the shareable NAG libraries to the default library search paths for the high performance 32-bit (-n32) and 64-bit libraries.

In the C shell use the command:

setenv LD_LIBRARYN32_PATH '/usr/lib32/mips3:/usr/lib32/mips4'

for high performance 32-bit (-n32) libraries and

setenv LD_LIBRARY64_PATH '/usr/lib64/mips3:/usr/lib64/mips4'

for 64-bit libraries.

In the Bourne shell the equivalent commands are:

LD_LIBRARYN32_PATH='/usr/lib32/mips3:/usr/lib32/mips4'
export LD_LIBRARYN32_PATH

and

LD_LIBRARY64_PATH='/usr/lib64/mips3:/usr/lib64/mips4'
export LD_LIBRARY64_PATH

If these environment variables are not set, the program may exhibit a fatal error indicating that it is not able to successfully map soname, 'libnagc.so'. For more information concerning runtime linker options, please refer to the 'rld' man page.

Similar considerations apply when using the Silicon Graphics provided Scientific Computing Software Library (SCSL) for using the SG provided BLAS and LAPACK subroutines. For example, in order to use the shareable library which requires the use of the SCSL library with ABI specified as -64 and ISA specified as -mips4

cc driver.c -64 -mips4 -lnagc_scs  -L/opt/scsl/1.4.0.1/usr/lib64 -lscs_i8 \
   -lpthread -lm

and you may also have to extend the environment variable LD_LIBRARY64 to include /opt/scsl/1.4.0.1/usr/lib64.

Due to a bug present in 2.1 and 2.2 of the R4000 processor, a warning message:

ld32: WARNING 47 : This module (../lib32/mips3/libnagc.a(p01zzct.o).text) 
contains branch instruction(s) that might degrade performance on an
older version (rev. 2.2) R4000 processor.

is output when linking with the mips3 libraries. This message can be switched off by specifying the option, -woff 47.

3.2. Example Programs

The example programs are most easily accessed by the command nagexample, which will provide you with a copy of an example program (and its data, if any), compile the program and link it with the library (showing you the compile command so that you can recompile your own version of the program). Finally, the executable program will be run, presenting its output to stdout. The example program concerned is specified by the argument to nagexample, e.g.

nagexample c06eac

will copy the example program and its data into the files c06eafe.c and c06eafe.d in the current directory and process them to produce the example program results.

The example programs supplied to a site in machine-readable form have been modified as necessary so that they are suitable for immediate execution. Note that the distributed example programs are those used in this implementation and may not correspond exactly with the programs published in the manual. The distributed example programs should be used in preference wherever possible.

The distributed example results are those obtained with a NAG static library, using the NAG BLAS and LAPACK functions. Running the examples with the shared library or non-NAG BLAS or LAPACK may give slightly different results.

4. Function-specific Information

Any further information which applies to one or more functions in this implementation is listed below, chapter by chapter.

(a) f06, f07 and f08

In the libnagc_scs.a and libnagc_scs.so libraries, calls to the Basic Linear Algebra Subprograms (BLAS) and linear algebra routines (LAPACK) are implemented by calls to the Scientific Computing Software Library (SCSL 1.4.0.1, 1.4.1.3 or compatible) except for the following functions:

ZDOTU      ZDOTC      ZHPEVD

(b) s10 - s21

Functions in this chapter will give error messages if called with illegal or unsafe arguments. General details are given in the NAG C Library Manual, but parameter limits which are implementation specific are given below:

s10aac  E(1)      = 18.500
s10abc  fail.code = NE_REAL_ARG_GT if X > 708.0
s10acc  fail.code = NE_REAL_ARG_GT if X > 708.0
 
s13aac  x(hi)     = 708.3
s13acc  x(hi)     = 5.6e+14
s13adc  x(hi)     = 5.6e+14
 
s14aac  fail.code = NE_REAL_ARG_GT if X > 170.
        fail.code = NE_REAL_ARG_LT if X < -170.
        fail.code = NE_REAL_ARG_TOO_SMALL if ABS(X) < 2.23e-308
s14abc  fail.code = NE_REAL_ARG_GT if X > 2.55e+305
 
s17acc  fail.code = NE_REAL_ARG_GT if X > 5.6e+14
s17adc  fail.code = NE_REAL_ARG_GT if X > 5.6e+14
        fail.code = NE_REAL_ARG_TOO_SMALL if X <= 2.23e-308
s17aec  fail.code = NE_REAL_ARG_GT if ABS(X) > 5.6e+14
s17afc  fail.code = NE_REAL_ARG_GT if ABS(X) > 5.6e+14
s17agc  fail.code = NE_REAL_ARG_GT if X > 103.8
        fail.code = NE_REAL_ARG_LT if X < -8.9e+9
s17ahc  fail.code = NE_REAL_ARG_GT if X > 104.1
        fail.code = NE_REAL_ARG_LT if X < -8.9e+9
s17ajc  fail.code = NE_REAL_ARG_GT if X > 104.1
        fail.code = NE_REAL_ARG_LT if X < -1.8e+9
s17akc  fail.code = NE_REAL_ARG_GT if X > 104.1
        fail.code = NE_REAL_ARG_LT if X < -1.8e+9
 
s18adc  fail.code = NE_REAL_ARG_TOO_SMALL if 0.0 < X <= 2.23e-308
s18aec  fail.code = NE_REAL_ARG_GT if ABS(X) > 711.6
s18afc  fail.code = NE_REAL_ARG_GT if ABS(X) > 711.6
s18cdc  fail.code = NE_REAL_ARG_TOO_SMALL if 0.0 < X <= 2.23e-308
 
s19aac  fail.code = NE_REAL_ARG_GT if ABS(X) >= 49.5000
s19abc  fail.code = NE_REAL_ARG_GT if ABS(X) >= 49.5000
s19acc  fail.code = NE_REAL_ARG_GT if X > 997.26
s19adc  fail.code = NE_REAL_ARG_GT if X > 997.26

s21bcc  fail.code = NE_REAL_ARG_LT if an argument <  1.579e-205
        fail.code = NE_REAL_ARG_GE if an argument >= 3.774e+202
s21bdc  fail.code = NE_REAL_ARG_LT if an argument < 2.820e-103
        fail.code = NE_REAL_ARG_GT if an argument > 1.404e+102

(c) x01

The values of the mathematical constants are provided in the header file nagx01.h:

X01AAC (pi)    = 3.1415926535897932
X01ABC (gamma) = 0.5772156649015329

(d) x02

The values of the machine constants are provided in the header file nagx02.h:

The basic parameters of the model

X02BHC = 2
X02BJC = 53
X02BKC = -1021
X02BLC = 1024
X02DJC = TRUE

Derived parameters of the floating-point arithmetic

X02AJC = 1.110223024625156800e-16
X02AKC = 2.225073858507201400e-308
X02ALC = 1.797693134862315700e+308
X02AMC = 2.225073858507201400e-308
X02ANC = 2.225073858507201400e-308

Parameters of other aspects of the computing environment

X02AHC = 5.629499534213120000e+14
X02BBC = 2147483647           (for 32-bit libraries)
X02BBC = 9223372036854775807  (for 64-bit libraries)
X02BEC = 15
X02DAC = FALSE

5. Documentation

Each supported NAG C Library site is ordinarily provided with a printed copy of the NAG C Library Introductory Guide. Additional documentation is available for purchase; please refer to the NAG websites or contact your local NAG Response Centre for current prices (see Section 6).

A full online version of the NAG C Library Manual is supplied in the form of Portable Document Format (PDF) files, with an HTML index, in the NAGdoc directory. The introductory material is also provided as HTML files in the NAGdoc directory.

A main index file has been provided (NAGdoc/cl/html/mark7.html) which contains a fully linked contents document pointing to all the available PDF (and where available HTML) files. Use your HTML browser to navigate from here.

6. Support from NAG

(a) Contact with NAG

Queries concerning this document or the implementation generally should be directed initially to your local Advisory Service. If you have difficulty in making contact locally, you can contact NAG directly at one of the addresses given in the Appendix. Users subscribing to the support service are encouraged to contact one of the NAG Response Centres (see below).

(b) NAG Response Centres

The NAG Response Centres are available for general enquiries from all users and also for technical queries from sites with an annually licensed product or support service.

The Response Centres are open during office hours, but contact is possible by fax, email and phone (answering machine) at all times.

When contacting a Response Centre it helps us deal with your enquiry quickly if you can quote your NAG site reference and NAG product code (in this case CLSG607DAL).

(c) NAG Websites

The NAG websites provide information about implementation availability, descriptions of products, downloadable software, product documentation and technical reports. The NAG websites can be accessed at

http://www.nag.co.uk/, http://www.nag.com/ (in North America) or http://www.nag-j.co.jp/ (in Japan)

(d) NAG Electronic Newsletter

If you would like to be kept up to date with news from NAG then please register to receive our free electronic newsletter, which will alert you to special offers, announcements about new products or product/service enhancements, customer stories and NAG's event diary. You can register via one of our websites, or by contacting us at nagnews@nag.co.uk.

7. User Feedback

Many factors influence the way NAG's products and services evolve and your ideas are invaluable in helping us to ensure that we meet your needs. If you would like to contribute to this process we would be delighted to receive your comments. Please contact your local NAG Response Centre (shown below).

Appendix - Contact Addresses

NAG Ltd
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Tel: +44 (0)1865 511245                 Tel: +44 (0)1865 311744
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NAG Inc
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Downers Grove
IL 60515-1362                           NAG Inc Response Center
USA                                     email: infodesk@nag.com
 
Tel: +1 630 971 2337                    Tel: +1 630 971 2345
Fax: +1 630 971 2706                    Fax: +1 630 971 2706
 
Nihon NAG KK
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4-9-9
Hatchobori
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Tokyo
104-0032
Japan
email: help@nag-j.co.jp

Tel: +81 (0)3 5542 6311
Fax: +81 (0)3 5542 6312