TNS/E Native Application Conversion Guide

C and C++ Conversion Tasks

TNS/E Native Application Conversion Guide—529659-003

3-5

Using IEEE Floating Point Format

TNS C and C++ programs use the HP proprietary TNS floating-point format. The native

C and C++ compilers provide the option of using either the TNS or the IEEE floating-

point format. The default option is IEEE format. Programs that depend on TNS format

must specify the TANDEM_FLOAT pragma (or -Wtandem_float flag) when

converted to native mode. Differences between IEEE and TNS floating-point formats

include:

•

Results of IEEE floating-point operations might differ slightly from those of TNS

floating-point operations.

•

IEEE floating-point values can include not-a-number (NaN) and infinity.

•

The sign of 0.0 (zero) in IEEE format can be either positive or negative.

Replacing Obsolete External Function

Declarations

External function declarations declare functions not written in the C language. Current

TNS C compilers recognize correctly, but issue warnings for, C-series external function

declaration syntax with newer replacements. The native compilers do not recognize the

C-series syntax. If you use FUNCTION pragma syntax or declarations with _language

name keywords (such as _tal and _c), no changes are required. See the

C/C++

Programmer’s Guide

for details.

Replacing Obsolete Keywords

Current TNS C compilers recognize, but issue warnings for, certain C-series keywords

with newer replacements. The native C compiler does not recognize the C-series

keywords. Replace the following C-series keywords with the equivalent replacement

keywords:

C-Series Keyword Replacement

cc_status _cc_status

extensible _extensible

extptr See the following paragraph

lowmem _lowmem

tal _tal

variable _variable

myproc ="

alias-name

" _alias("

alias-name

") myproc

(or use the FUNCTION pragma syntax instead—see the

C/C++ Programmer’s Guide

for more information)