HP Fortran Programmer's Guide (September 2007)

Compiling and linking
Compiling with the f90 command
Chapter 268
Note, however, that the +Oinline_budget option takes precedence over
both of these options. This means that you can override the effect of
+Onolimit or +Osize option on inlining by specifying the +Oinline_budget
option on the same command line.
This option is only effective at optimization level 3 or higher.
+O[no]libcalls
invokes millicode versions of a number of frequently called intrinsic
functions; see Table on page 68. Millicode routines have very low call
overhead and provide no error-handling. Use this option to improve the
performance of selected library routines only when your program does not
depend upon exception-handling.
The default is +Onolibcalls at optimization levels 0 and 1; at optimization
level 2 or higher, the default is +Olibcalls.
+o[no]libmerrno
Enable [disable] support for errno in libm functions.
Table 2-10 Values for the +Oinline_budget option
Values for n Meaning
= 100 Default level of inlining.
> 100 More aggressive inlining. The optimizer is less
restricted by compilation time and code size when
searching for eligible routines to inline.
2 - 99 Less aggressive inlining. The optimizer gives more
weight to compilation time and code size when
determining whether to inline.
= 1 Only inline if it reduces code size.
Table 2-11 Millicode versions of intrinsic functions
acos cos pow
asin exp sin
atan log tan
atan2 log10