HP Fortran Programmer's Guide (B3908-90031; September 2011)

Compiling and linking
Compiling with the f90 command
Chapter 2 71
+o[no]libmerrno
Enable [disable] support for errno in libm functions.
The default is +Onolibmerrno.
+O[no]loop_block
+O[no]loop_block enables or disables blocking of eligible loops for improved cache
performance. The +Onoloop_block option disables both automatic and
directive-specified loop blocking.
+O[no]loop_transform
+Oloop_transform enables transformation of eligible loops for improved cache
performance. The most important transformation is the interchange of nested loops to
make the inner loop unit stride, resulting in fewer cache misses.
+Onoloop_transform disables transformation of eligible loops. The default is
+Oloop_transform.
NOTE This option is deprecated and not supported in future releases. Use
+inline_level.
+inline_level num
This option controls inlining in fortran. The format for num is N[.n], where num is
either an integral value from 0 to 9 or a value with a single decimal place from 0.0 to
9.0.
For more information on this option, see F90(1) manpage.
+O[no]loop_unroll[=factor]
+Oloop_unroll turns on loop unrolling. factor is the unroll factor that controls the
code expansion. The default unroll factor is 4; that is, four copies of the loop body. By
experimenting with different factors, you may improve the performance of your
program. This option is only effective at optimization level 2 or higher.
The default is +Oloop_unroll=4.
+O[no]loop_unroll_jam
atan2 log10
Table 2-11 Millicode versions of intrinsic functions (Continued)