O

object files

compile only–c

name–o filename

object library search directories–Lpath

object-oriented FortranObject-Oriented Fortran Support

obsolete command-line optionsObsolete Option Flags

octalOctal

OMP_NUM_THREADS, number of threads–autopar

one-trip DO loops–onetrip

OpenMPOpenMP Parallelization Directives

directives summaryFortran OpenMP Directives

OPT directiveThe OPT Directive

-xmaxopt option–xmaxopt[=n]

optimization

across source files–xipo[={0|1|2}]

aliasing–xalias[=keywords]

floating-point–fsimple[={1|2|0}]

inline user-written routines–inline=[%auto][[,][no%]f1,…[no%]fn]

interprocedural–xipo[={0|1|2}]

levels–O[n]

link-time–xlinkopt[={1|2|0}]

loop unrolling–unroll=n

loop unrolling by directiveThe UNROLL Directive

math library–xlibmopt

OPT directive

–xmaxopt[=n]

The OPT Directive

PIPELOOP directiveThe PIPELOOP[=n] Directive

PREFETCH directiveThe PREFETCH Directives

specify cache–xcache=c

specify instruction set architecture–xarch=isa

specify processor–xchip=c

target hardware–native

with -fast–fast

with debugging–g[n]

options  Seecommand-line options

order of

functions–xF

order of processing, optionsTypographic Notations for Options

overflow

stack–stackvar

trap on floating-point–ftrap=t

overindexing

aliasing–xalias[=keywords]