HP UX Fortran Software +Ocachepadcommon option, Default is +Onocxlimitedrange, +Onodynopt

Page 41

 

Note the following precautions when using this option:

 

All program modules that reference the common

 

block must be compiled with the

 

+Ocache_pad_common option.

 

Each common block in the program should have

 

the same layout in all program units within which

 

it is declared. If the layouts are different, they must

 

be fully independent—that is, they must not pass

 

values between them.

 

The default, +Onocache_pad_common, disables

 

padding.

+O[no]cxlimitedrange

Enables [disables] the use of floating point math in the

 

compilation unit.

 

The default is +Onocxlimitedrange.

+O[no]cross_region_addressing

Enable [disable] the use of cross-region addressing.

 

Cross-region addressing is required if a pointer (such

 

as an array base) points to a different region than the

 

data being addressed. This is usually due to an offset

 

which results in a cross-over into another region.

 

Standard-conforming applications do not require the

 

use of cross-region addressing. The default is

 

+onocross_region_addressing.

+O[no]dataprefetch

+Odataprefetch causes the optimizer to insert

 

instructions within innermost loops to explicitly prefetch

 

data from memory into the data cache. Data prefetch

 

instructions will be inserted only for data structures

 

referenced within innermost loops using simple loop

 

varying addresses—that is, in a simple arithmetic

 

progression. It is not available for PA-RISC 1.1 targets.

 

Use this option for applications that have high data

 

cache miss overhead. The default is

 

+Onodataprefetch. On HP-UX version 11i and

 

later, +Odataprefetch is the same as

 

+Odataprefetch=indirect and

 

+Onodataprefetch is the same as

 

+Odataprefetch=none.At +O2and higher, the

 

default is +Odataprefetch.

+O[no]dataprefetch=[directindirectnone]

Control generation of data prefetch instructions for

 

data structures referenced within innermost loops. The

 

defined values for kind are:

 

direct—enable generation of data prefetch

 

instructions for the benefit of direct memory accesses,

 

but not indirect memory accesses.

 

indirect—enable generation of data prefetch

 

instructions for the benefit of both direct and indirect

 

memory accesses. This is the default at optimization

 

levels +O2 and above.

 

none—disable generation of data prefetch instructions.

 

This is the default at optimization levels +O1 and

 

below.

+O[no]dynopt

Enable [disable] dynamic optimization for the output

 

file, if the run-time environment supports this feature.

 

Both forms of this option change the default setting,

 

which allows the run-time environment to enable or

 

disable dynamic optimization according to

 

asystem-wide default. This option applies only to

 

executable files and shared libraries. chatr(1) can

 

be used to change this setting, including restoration

 

of the default setting, after the output file has been

 

created.

Fine-tuning optimization options

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Contents Abstract HP Fortran Programmer GuidePage Contents Controlling data storage Using the on statementDebugging Performance and optimizationWriting HP-UX applications 107 Using Fortran directives 123Calling C routines from HP Fortran 110 Migrating to HP Fortran 131Documentation Feedback 153 Glossary 154 Index 159 Fortran 2003 Features 151Porting to HP Fortran 141 HP secure development lifecycle An overview of HP Fortran An overview of HP FortranHP Fortran compiler environment Options for controlling the f90 driver Driver+dryrun +preinclude= fileOptions for controlling the C preprocessor PreprocessorOptions for controlling the front end Front-end+moddir=directory Options for controlling optimization Back-end+Onooptimization Options for controlling code generationOptimization +DAmodelOptions for controlling the Linker LinkerOoutfile +FPflagsLdirectory Wl ,options ToolsHP-UX operating system F90 command syntax Compiling with the f90 commandCompiling and linking $ f90 hello.f90F90 command syntax Command-line optionsCommand-line options Example 2 hello.f90Commonly-used options Command-line options by categoryCommonly-used options +saveOptions listed by category Option descriptions+allowunaligned Example 3 ExampleDo I+1, N 14164 Data type sizes and +autodbl4+autodbl +autodbl4 Boption+charlit77 +cpp=default+check=bounds +nocfc+DAmodel Name=def+DDdatamodel DatamodelareItanium BlendedItanium2 NativeValues for the +FP option +hugecommon Signals recognized by the +fpexception optionGformat77 Example 4 % f90 +hugecommon=results pcvals.f90 +indirectcommonlist=file /usr/include directory +noimplicitnone+initheapcomplex=rvalival +initheapinteger=ivalIpo +io77+nocheckuf +nolibsRequires concurrent use of the +Oprofile=use option Levels of optimizationWith different values of optlevel +noobjdebug+pa1 +nodemandload the default +demandload option. The default is +nodemandload+r8 +realconstant=singleTp,/usr/ccs/lbin/cpp Tx,pathF90com End.oWx,arg1,arg2,...,argN Bdefault=symbol,symbol Symbol binding optionsBextern =symbol ,symbol Bhidden =symbol ,symbolF90 +O3 +Osize myprog.f90 Using optimization optionsReviewing general optimization options +Onoall +Oconservative+Onoautopar +Oautopar and omit +OparallelF90 +O3 +Onomoveflops +Ofltacc myprog.f90 Fine-tuning optimization optionsDefault is +Odataprefetch Default is +Onocxlimitedrange+Ocachepadcommon option +Onocxlimitedrange+Onofastaccess +Onofenvaccess+Onoentrysched +OnofailsafeOptimizations performed by +Onofltacc +Onoinline +Oinlinebudget=n +Oinlinebudget enables+Onoinlinefilename +Onoinline=function1,function2Millicode versions of intrinsic functions Values for the +Oinlinebudget option+Onoloopunroll=factor +inlinelevel num+Oloopunroll=4 +Onoloopunrolljam+Oparallelintrinsics Default is+Onoparmsoverlap+Onoparmsoverlap +Onopipeline+Onorecovery Default is +OnopromoteindirectcallsDefault is +Oshortdata=8 For +Oprofile=collectarc,strideFilenames recognized by f90 FilenamesLinking with f90 vs. ld Linking HP Fortran programsLibraries linked by default on Itanium Libraries linked by default on PA-RISCLinking to libraries $ f90 -c hello.f90 # compileLinking HP Fortran 90 routines Linking to nondefault librariesOpt/fortran90/lib/pa2064/ -lF90 -lisamstub Additional HP Fortran librariesLinking to shared libraries Compiling programs with modules Special-purpose compilationsLibrary search rules $ f90 -Wl,-a,archive prog.f90 -lmSpecial-purpose compilations Example ExamplesExample 6 Example 2-2 main.f90 Example 7 Example 2-3 code.f90Example 8 Example 2-4 data.f90 Compiling with make$ f90 -o dostats data.f90 code.f90 main.f90 $ dostatsManaging .mod files Compiling for different PA-RISC machinesExample 9 Example 2-5 makefile $ makeCompiling with +pic Creating shared librariesLinking with -b Using the C preprocessorProcessing cpp directives Using the C preprocessorExample 13 Example 2-9 cppdirect.f90 $ f90 +cpp=yes -D Debug cppdirect.f90Saving the cpp output file Creating demand-loadable executablesCreating shared executables Using environment variables Compiling in 64-bit mode$ f90 +noshared prog.f90 HP Fortran environment variablesSTF90COM64 environment variable F90ROOT environment variableHPF90OPTS environment variable $ f90 +list hello.f90Floating installation Floating installationLpath environment variable Mpnumberofthreads environment variableAlternate-path/opt/fortran90.3.6.1 Setting up floating installationDisabling implicit typing Controlling data storageAutomatic and static variables Disabling implicit typingControlling data storage ContainsIncreasing the precision of constants Increasing default data sizes Increasing default data sizesIncreasing default data sizes Which creates multiple threads Sharing data among programsUsr/lib/libpthread.sl Sharing data among programs $ gotosleepIm up Modules vs. common blocks$ wakeup Modules vs. common blocks Stripping debugging information Using the HP WDB debuggerDebugging Signal Signals recognized by +fpexceptionHandling runtime exceptions Floating-point exceptions= 1.0/0.0 Bus error exceptionFloating-point exceptions Segmentation violation exception Illegal instruction exceptionBad argument exception Using debugging linesExceptions handled by the on statement Using the on statementOn REAL8 DIV 0 Call divzerotrap Exceptions handled by the on statementExceptions handled by the on statement Actions specified by onOn Double Precision DIV 0 Call divzerotrap Terminating program execution Ignoring errorsExample 14 Example5-1 abort.f90 Example 15 Example5-2 ignore.f90Trapping floating-point exceptions Calling a trap procedureTrapping integer overflow exceptions On Double Precision Overflow Call trapExample 17 Example5-4 callitrap.f90 Trapping +Ctrl-C trap interruptsAllowing core dumps On Real Overflow Ignore Example 18 Example 5-5 allowcore.f90Using profilers Using profilersPerformance and optimization HP CaliperOpt/ansic/bin/cc -Aa +O3 -o program +Oprofile=collect Comparing Program PerformanceProgram.c ProgramprogramargumentsGprof Using Options to Control Data CollectionSpecifying PBO file names and locations $ gprof prog gprof.outUsing +O to set optimization levels Using options to control optimizationProf $ f90 +O4 file.f90+O2, -O Using the optimization options+O3 +O4$ f90 +02 +Oaggressive +Osize prog.f90 Fine-tuning optimization options$ f90 +O4 +Oaggressive +Ofltacc prog.f90 Packaged optimization options+Ofastaccess at level Is +Onofastaccess at+O2 +Ofltacc=relaxed+Onoinitcheck +Ofltacc=relaxed . ThisFast +Onolibcalls +Oinlinelevel num+Olibcalls +Onoloopunroll=n+Opipeline +Onoparminit+Orecovery +Onoreturn +Oregreassoc+Oshortdata=8 +Ovectorize option on+Owholeprogrammode Conservative vs. aggressive optimization+Onowholeprogrammode Parallelizing HP Fortran programs Conservative, aggressive, and default optimizationsCompiling for parallel execution F90 +O3 +Oparallel -c x.f90 y.f90 F90 +O3 -c z.f90Profiling parallelized programs Performance and parallelizationConditions inhibiting loop parallelization Calling routines with side effects parallellizationData dependences Indeterminate iteration countsVectorization Using the +Ovectorize optionF90 +O3 +Ovectorize prog.f90 Vector routines called by +OvectorizeSaxpy Controlling vectorization locallySdot VecdmultaddExample 19 Example 6-1 axpy.f90 Calling Blas library routinesREAL, External sdot Industry-wide standard VectorizationControlling code generation for performance Writing HP-UX applications Accessing command-line arguments$ fprog arg1 another arg Example 20 Example 7-1 getargs.f90Stream I/O using Fstream Using HP-UX file I/OPerforming I/O using HP-UX system calls Calling HP-UX system and library routinesObtaining an HP-UX file descriptor Using HP-UX file I/OData type correspondence for HP Fortran and C Calling C routines from HP FortranData types Logicals Unsigned integersSize differences between HP Fortran and C data types Size differences after compiling with +autodblExample 21 Example 8-1 passcomplex.f90 Complex numbersComplex sqrcomplexCOMPLEX cmxval Derived types Argument-passing conventionsPointers Example 22 Example 8-2 sqrcomplex.cCase sensitivity Integer ptr INTEGER, DIMENSION100 iarrayVoid fooint *ptr, int iarray100, int Call foo%REFptr, %REFiarray, %VALi$HP$ Alias bubblesort = BubbleSort%REF,%VAL Example 23 Example 8-3 sortem.cExample 24 Example 8-4 testsort.f90 Case sensitivityREAL, DIMENSION2,3,4 Memory layout of a two-dimensional array in Fortran and CArrays IntExample 26 Example 8-6 getarray.c Example 25 Example 8-5 passarray.f90Null-terminated string StringsFortran hidden length argument Passing a stringStrings Following are example C and Fortran programsExample 28 Example 8-8 getstring.c File handlingExample 27 Example 8-7 passchars.f90 File handling Example 29 Example 8-9 fnumtest.f90Int somedata Sharing dataExtern int somedata Extern int globals100Using HP Fortran directives Using Fortran directivesDirective syntax HP Fortran directivesDescription and restrictions Syntax$HP$ Alias name = external-name arg-pass-mode-list NameArgument-passing conventions Local and global usageCase sensitivity For more information StringsExample 31 Example 9-1 prstr.c Example 32 Example 9-2 passstr.f90Specified on the command line Disables the inclusion of source lines in the listing fileExample 33 Example Listing fileControlling vectorization Compatibility directivesCompatibility directives recognized by HP Fortran Vendor Directive CrayControlling dependence checks Controlling parallelizationControlling checks for side effects Compatibility directivesUsing Fortran directives Migrating to HP Fortran Command-line options not supportedIncompatibilities with HP Fortran Compiler limitsFloating-point constants Format field widthsIntrinsic functions Double Precision x =Data types and constants Procedure calls and definitionsDirectives Input/outputFoo**REALbar, 8 ! foo**bar KEY=Source code issues Migration issuesMigration issues MiscellaneousHP Fortran 77 directives supported by f90 options DirectivesIntrinsic functions Command-line option issuesConflicting intrinsics and libU77 routine names F77 options supported by f90Data file issues Object code issuesHP-supplied migration tools Approaches to migration$ fid +800 file.f $ fid +es program.f Compatibility extensions Porting to HP FortranCompatibility statements END structure definitionCompatibility directives Compiler directivesPointer Cray-style +Oparallel orNonstandard intrinsic procedures in HP Fortran Intrinsic proceduresDirective prefixes recognized by HP Fortran +Oparallel or +OvectorizeUninitialized variables Using porting optionsLarge word size Using porting optionsOne-trip do loops $ f90 testloop.f90External int1 Name conflictsExample 34 Example 11-1 clash.f90 Source formats Names with appended underscores+cfc Porting from Tru64 to HP FortranEscape sequences New options EnhancementsNof66alternate for +noonetrip Porting from Tru64 to HP Fortran+nopadsrc Altparam Check noboundsoptions for example, -nocheckboundsInteroperability with C Fortran 2003 FeaturesInput/output enhancements Miscellaneous enhancementsData enhancements Object orientation featuresFortran 2003 Features 153 Documentation FeedbackGlossary Glossary155 So on. See also row-major orderAlso filename extension 157 Memory faultSee ttv 159 SymbolsIndex