HP aC++/HP C A.06.25 Release Notes

compiler uses, and the "decimal encoding". Both encodings provide exactly the
same data, analogous to big endian and little endian encodings.
• Decimal FP I/O and string conversion. The decimal FP length modifiers for
printf() and scanf() floating-point conversion specifiers (a, A, e, E, f, F, g, G)
are H for _Decimal32, D for _Decimal64, and DD for _Decimal128. The decimal a,
A specifiers for printf(), given no precision or sufficient precision, produce an
exact quantum-preserving representation of the decimal FP value being converted.
• WDB debugger support for printing values of decimal FP types.
• Suffixes to designate decimal floating constants: df or DF for _Decimal32, dd or
DD for _Decimal64, and dl or DL for _Decimal128. Note that an unsuffixed floating
constant still has type double, regardless of the context. Explicit suffixing with a
d or D to specify type double is also allowed.
• Decimal FP versions of macros in <float.h>, <math.h>, and <fenv.h>.
• Five rounding modes for decimal FP: to nearest with ties to even, to nearest with
ties away from zero, upward, downward, and toward zero.
• Compiler option +decfp, which enables full decimal FP functionality according
to the ISO/IEC C draft Technical Report: http://www.open-std.org/jtc1/
sc22/wg14/www/docs/n1312.pdf
• Compiler option -fpevaldec=precision, which specifies the minimum
precision to use for decimal floating-point expression evaluation. The possible
values for precision are _Decimal32, _Decimal64, and _Decimal128. This
option does not affect the precision of parameters, return types, or assignments.
The default is -fpevaldec=_Decimal32.
• Type-generic functions in <tgmath.h> that take on the type of decimal FP (or
binary FP) arguments.
• Our Decimal FP support incorporates code from the Intel Decimal Floating-Point
Math Library.
To use decimal FP:
• Install the following on an HP-UX 11i V3 (11.31) Integrity system:
— core Math patch PHSS_38137
— math manpage patch PHCO_38388
— libc patch PHCO_38048
— libcEnhancement package (http://docs.hp.com/en/5992-3373/ch10s12.html)
— libc man page patch PHCO_37128 (for printf and scanf man pages)
• To use any decimal FP functionality (even built-in operators), add the +decfp
option to the compile and link lines.
• To use the decimal FP functionality in <math.h>, <float.h>, <fenv.h>, or
<tgmath.h>, define __STDC_WANT_DEC_FP__ before including the header.
New Features in Version A.06.20 21