HP Fortran Programmer's Guide (March 2010)

Performance and optimization
Conservative vs. aggressive optimization
Chapter 6166
+Oconservative •Nonstandard
• Sensitive to rounding differences
• Contains floating-point expressions
that must be evaluated in the
specified order
• Procedure arguments may overlap
+Ofltacc
+Onomoveflops
+Oparmsoverlap
+Oaggressive • Standard-conforming
• Contains floating-point expressions
that permit re-ordering for
optimization
• Does not contain uninitialized
variables
+Oentrysched
+Onofltacc
+Onoinitcheck
+Ovectorize
Table 6-4 Conservative, aggressive, and default optimizations (Continued)
Specified options Assumptions Invoked options