HP aC++/HP C Programmer's Guide (B3901-90036; A.06.26; September 2011)

The -fast option selects a combination of optimization options for optimum execution
speed and reasonable build times. Currently chosen options are:
• +O2
• +Ofltacc=relaxed
• +Onolimit
• +DSnative
• +FPD
You can override any of the options in -fast by specifying a subsequent option after
it. This option is equivalent to +Ofast.
Use this option when porting C++ and C applications compiled on other UNIX operating
systems to HP-UX.
NOTE: Do not use this option for programs that depend on IEEE standard floating-point
denormalized numbers. Otherwise, different numerical results may occur.
+sb
+sb
The +sb option specifies unqualified char, short, int,long, and long long bitfields
as signed. The default is +sb.
NOTE: When both +sb and +uc are in effect, +uc will override this for char bit fields.
+ub
+ub
The +ub option specifies unqualified char, short, int, long, and long long bitfields
as unsigned. This option has no effect on signedness of enum bitfields or on signedness
of non-bitfield char. The default is +sb.
+uc
+uc
By default, all unqualified char data types are treated as signed char. Specifying +uc
causes an unqualified (plain) char data type to be treated as unsigned char.
(Overloading and mangling are unchanged.)
Use this option to help in porting applications from environments where an unqualified
(plain) char type is treated as unsigned char.
Porting Options 85