Pragma equivalent
#pragma options [no]ldbl128
Purpose
Increases the size of long double types
from 64 bits to 128 bits.
Syntax

.-ldbl128---.
>>- -q--+-noldbl128-+------------------------------------------><
Usage
The #pragma options directive
must appear before the first C or C++ statement
in the source file, and the option applies to the entire file.
Predefined macros
- __LONGDOUBLE128 and __LONG_DOUBLE_128__ are defined
to 1 when -qldbl128 is in effect; otherwise, they are undefined.
- __LONGDOUBLE64 is defined to 1 when -qnoldbl128 is in effect; it
is undefined when -qldbl128 is in effect.
Examples
To compile
myprogram.c so
that long double types are 128 bits, enter:
xlc myprogram.c -qldbl128