User's Guide
The following tables show the compiler options available in the XL Fortran
compiler that you can enter in the configuration file, on the command line, or
in the Fortran source code using the @PROCESS compiler
directive.
You can enter compiler options that start with -q, suboptions, and @PROCESS directives in
either uppercase or lowercase. However, note that if you specify the
-qmixed option, procedure names that you specify for the -qextern option are case-sensitive.
In general, this book uses the convention of lowercase for -q
compiler options and suboptions and uppercase for @PROCESS
directives. However, in the "Syntax" sections of this chapter, and in
the "Command-Line Option" column of the summary tables, we use uppercase
letters in the names of -q options, suboptions, and @PROCESS
directives to represent the minimum abbreviation for the keyword. For
example, valid abbreviations for -qOPTimize are -qopt,
-qopti, and so on.
Understanding the significance of the options you use, and knowing the
alternatives available, can save you considerable time and effort in making
your programs work correctly and efficiently.
The following options affect the compiler input at a high level. They
determine which source files are processed, and select case sensitivity,
column sensitivity, and other global format issues.
Many of the options in Options for Compatibility change the permitted input format slightly.
Figure 5. Options That Control Input to the Compiler
| Command-Line Option
| @PROCESS Directive
| Description
| See Page
|
| -Idir
|
| Adds a directory to the search path for include files and
.mod files. If XL Fortran calls cpp, this
option adds a directory to the search path for #include files.
Before checking the default directories for include and .mod
files, the compiler checks each directory in the search path. For
include files, this path is only used if the file name in an INCLUDE
line is not provided with an absolute path. For #include
files, refer to the cpp documentation for the details of the
-I option.
| Default: | The following directories are searched, in this order:
- The current directory
- The directory where the source file is
- /usr/include
|
| -I Option
|
| -qci=numbers
| CI(numbers)
| Activates the specified INCLUDE lines.
| Default: | No default value.
|
| -qci Option
|
-qdirective
[=directive_list]
-qnodirective
[=directive_list]
|
DIRECTIVE
[(directive_list)]
NODIRECTIVE
[(directive_list)]
| Specifies sequences of characters, known as trigger constants, that
identify comment lines as compiler comment directives.
| Default: | Comment lines beginning with IBM* are considered directives. If you specify
-qsmp=omp, only $OMP is considered to be a directive trigger.
All other directive triggers are turned off, unless you explicitly turn them
back on. If you specify -qsmp=noomp (noomp is the default for -qsmp),
IBMP, $OMP and SMP$ are considered directive
triggers, along with any other directive triggers that are turned on (such as
IBM* and IBMT). If you have also specified
-qthreaded, comment lines beginning with IBMT are also considered
directives.
|
| -qdirective Option
|
-qfixed
[=right_margin]
|
FIXED
[(right_margin)]
| Indicates that the input source program is in fixed form, and optionally
specifies the maximum line length.
| Default: | -qfree=f90 for the xlf90, xlf90_r, xlf90_r7,
xlf95, xlf95_r, and xlf95_r7 commands, and
-qfixed=72 for the xlf, xlf_r, xlf_r7, and
f77 commands.
|
| -qfixed Option
|
-qfree[={f90|ibm}]
-k
|
FREE[({F90|
IBM})]
| Indicates that the source code is in free form. The ibm and f90 suboptions specify compatibility with the free form defined for VS
FORTRAN and Fortran 90/Fortran 95, respectively. -k and -qfree are short forms for
-qfree=f90.
| Default: | -qfree=f90 for the xlf90, xlf90_r, xlf90_r7,
xlf95, xlf95_r, and xlf95_r7 commands, and
-qfixed=72 for the xlf, xlf_r, xlf_r7, and
f77 commands.
|
| -qfree Option
|
-qmbcs
-qnombcs
|
MBCS
NOMBCS
| Indicates to the compiler whether character literal constants, Hollerith
constants, H edit descriptors, and character string edit descriptors can
contain Multibyte Character Set (MBCS) or Unicode characters.
| -qmbcs Option
|
-U
-qmixed
-qnomixed
|
MIXED
NOMIXED
| Makes the compiler sensitive to the case of letters in names.
| -U Option
|
| -qsuffix={suboptions}
|
| Specifies the source-file suffix on the command line.
| -qsuffix Option
|
The following options specify names or directories where the compile stores
output files.
In the table, an * indicates that the option is processed
by the ld command rather than the XL Fortran compiler; you can find
more information about these options in the AIX information for the
ld command.
Figure 6. Options That Specify the Locations of Output Files
| Command-Line Option
| @PROCESS Directive
| Description
| See Page
|
| -d
|
| Leaves preprocessed source files produced by cpp, instead of
deleting them.
| Default: | Temporary files produced by cpp are deleted.
|
| -d Option
|
| -o name*
|
| Specifies a name for the output object, executable, or assembler source
file.
| -o Option
|
| -qmoddir=directory
|
| Specifies the location for any module (.mod) files that
the compiler writes.
| Default: | .mod files are placed in the current directory.
|
| -qmoddir Option
|
The following options can help you to speed up the execution of your XL
Fortran programs, or to find areas of poor performance that can then be
tuned. The most important such option is -O. In
general, the other performance-related options work much better in combination
with -O; some have no effect at all without -O.
Some of the options in Options for Floating-Point Processing can also improve performance, but you must use them with
care to avoid error conditions and incorrect results.
Figure 7. Options for Performance Optimization
| Command-Line Option
| @PROCESS Directive
| Description
| See Page
|
-O[level]
-qoptimize[=level]
-qnooptimize
|
OPTimize[(level)]
NOOPTimize
| Specifies whether code is optimized during compilation and, if so, at
which level (2, 3, or 4).
| -O Option
|
| -P{v|k}[!]
|
| Invokes the selected optimizing preprocessor. Adding ! prevents the compilation step from following
preprocessing.
| Note: | The preprocessors are available as separate vendor-logo products.
|
| Default: | No preprocessing.
|
| -P Option
|
-p
-pg
|
| Sets up the object file for profiling.
| -p Option
|
-Q
-Q!
-Q+names
-Q-names
|
| Specifies whether procedures are inlined, and/or particular procedures
that should or should not be inlined. names is a list of
procedure names separated by colons.
| -Q Option
|
-qalias=
{[no]aryovrlp |
[no]intptr |
[no]std}...]
|
ALIAS(
{[NO]ARYOVRLP
| [NO]INTPTR
| [NO]STD}... )
| Indicates whether a program contains certain categories of
aliasing. The compiler limits the scope of some optimizations when
there is a possibility that different names are aliases for the same storage
locations.
| Default: | -qalias=aryovrlp:nointptr:std for the xlf90,
xlf90_r, xlf90_r7, xlf95, xlf95_r, and
xlf95_r7 commands; -qalias=aryovrlp:intptr:std for the
xlf, xlf_r, xlf_r7, and f77
commands.
|
| -qalias Option
|
| -qalign=[no]4k
| ALIGN ([NO]4K)
| Specifies the alignment of data objects in storage, to avoid performance
problems with misaligned data. Currently, this option is mainly useful
in combination with logical volume I/O and disk striping, and is very
important for achieving performance gains with these types of I/O.
| -qalign Option
|
| -qarch=architecture
|
| Specifies what types of RISC systems the application program can be
executed on. Changing the default can improve performance, but might
restrict the set of machines that can run the program. The choices are
com, auto, rs64a, rs64b, p2sc, pwr, pwr2 (or pwrx), pwr3, pwr2s, ppc, 601, 603, and 604.
| Default: | -qarch=com, (if you specify -q32),which uses only instructions that are common
to all platforms. If you specify -q64, the default is ppc, which
allows you to run the executable file on any 64-bit PowerPC hardware
platform.
|
| -qarch Option
|
-qassert={ deps |
nodeps | itercnt=n}
|
| Provides information about the characteristics of the files that can help
to fine-tune optimizations.
| Default: | -qassert=deps:itercnt=1024.
|
| -qassert Option
|
-qcache={
auto |
assoc=number |
cost=cycles |
level=level |
line=bytes |
size=Kbytes |
type={C|D|I}}[:...]
|
| Specifies the cache configuration for a specific execution
machine. The compiler uses this information to tune program
performance, especially for loop operations that can be structured (or blocked) to process only the amount of data that can fit into the data
cache.
| Default: | The compiler uses typical values based on the -qtune setting, the
-qarch setting, or both settings.
|
| -qcache Option
|
-qcompact
-qnocompact
|
COMPACT
NOCOMPACT
| Reduces optimizations that increase code size.
| -qcompact Option
|
-qfdpr
-qnofdpr
|
| Provides object files with information needed for the AIX fdpr (Feedback
Directed Program Restructuring) performance-tuning utility to optimize the
resulting executable file.
| -qfdpr Option
|
-qhot[=[no]arraypad[=n]]
-qnohot
|
| Determines whether to perform high-order transformations on loops and
array language during optimization, and whether to pad array dimensions and
data objects to avoid cache misses.
| -qhot Option
|
| -qipa[=suboptions]
|
| Enhances -O optimization by doing detailed analysis across procedures
(interprocedural analysis or IPA)
| Default: | -O analyzes each subprogram separately, ruling out certain
optimizations that apply across subprogram boundaries.
|
| -qipa Option
|
| -qpdf{1|2}
|
| Tunes optimizations through profile-directed feedback (PDF),
where results from sample program execution are used to improve optimization
near conditional branches and in frequently executed code sections.
| Default: | Optimizations use hardcoded assumptions about branch frequency and other
statistics.
|
| -qpdf Option
|
-qsmp[=suboptions]
-qnosmp
|
| Controls automatic parallelization of loops, user-directed
parallelization of loops and other items, and the choice of chunking algorithm, when used with
xlf_r, xlf_r7, xlf90_r, xlf90_r7,
xlf95_r, or xlf95_r7.
| -qsmp Option
|
-qstrict
-qnostrict
|
STRICT
NOSTRICT
| Ensures that optimizations done by the -O3, -qhot, and -qipa options do not alter the semantics of a Fortran 90 or Fortran 95
program.
| Default: | With -O3 in effect, code may be rearranged so that results or exceptions are
different from those in unoptimized programs.
|
| -qstrict Option
|
-qstrict_induction
-qnostrict_induction
|
|
Prevents the compiler from performing induction (loop counter) variable
optimizations. These optimizations may be unsafe (may alter
the semantics of your program) when there are integer overflow operations
involving the induction variables.
| Default: | -qnostrict_induction.
|
| -qstrict_induction Option
|
-qsuppress=
nnnn-mmm[:nnnn-mmm...]
-qnosuppress
|
| Specifies selective messages to suppress from the output stream.
| -qsuppress Option
|
| -qthreaded
|
| Specifies that the compiler should generate thread-safe code. This
is turned on by default for the xlf_r, xlf_r7, xlf90_r,
xlf90_r7, xlf95_r, and xlf95_r7
commands.
| -qthreaded Option
|
| -qtune=implementation
|
| Tunes instruction selection, scheduling, and other
implementation-dependent performance enhancements for a specific
implementation of a hardware architecture. The following settings are
valid: auto, 601, 603, 604, pwr, pwr2 (or pwrx), pwr3, pwr2s, rs64a, rs64b,
or p2sc.
| Default: | Determined by the setting of the -qarch option.
|
| -qtune Option
|
-qzerosize
-qnozerosize
|
ZEROSIZE
NOZEROSIZE
| Improves performance of FORTRAN 77 and some Fortran 90 and Fortran 95
programs by preventing checking for zero-sized character strings and
arrays.
| Default: | -qzerosize for the xlf90, xlf90_r, xlf90_r7,
xlf95, xlf95_r, and xlf95_r7 commands, and -qnozerosize for the xlf, xlf_r, xlf_r7, and f77 commands (meaning these commands
cannot be used for programs that contain zero-sized objects).
|
| -qzerosize Option
|
The following options help you avoid, detect, and correct problems in your XL Fortran programs, and can save you having to refer as
frequently to Chapter 11. Problem Determination and Debugging.
In particular, -qlanglvl helps detect portability problems early
in the compilation process by warning of potential violations of the Fortran
standards. These can be due to extensions in the program, or due to compiler
options that allow such extensions.
Other options, such as -C and -qflttrap, detect and/or
prevent run-time errors in calculations, which could otherwise produce
incorrect output.
Because these options require additional checking at compile time, and some of
them introduce run-time error checking that slows execution, you may need to
experiment to find the right balance between extra checking and slower
compilation and execution performance.
Using these options can help to minimize the amount of problem
determination and debugging you have to do. Other options you may find useful while debugging include:
Figure 8. Options for Debugging and Error Checking
| Command-Line Option
| @PROCESS Directive
| Description
| See Page
|
-C
-qcheck
-qnocheck
|
CHECK
NOCHECK
| Checks each reference to an array element, array section, or character
substring for correctness. Out-of-bounds references are reported as
severe errors if found at compile time, and generate SIGTRAP signals
at run time.
| -C Option
|
-D
-qdlines
-qnodlines
|
DLINES
NODLINES
| Specifies whether fixed-form lines with a D in column 1 are compiled or
treated as comments.
| -D Option
|
-g
-qdbg
-qnodbg
|
DBG
NODBG
| Generates debug information for use by a symbolic debugger.
| -g Option
|
-qdpcl
-qnodpcl
|
DPCL
NODPCL
| Generates symbols that tools based on the Dynamic Probe Class Library
(DPCL) can use to see the structure of an executable file.
| -qpdcl Option
|
-qextchk
-qnoextchk
|
EXTCHK
NOEXTCHK
| Sets up type-checking information for common blocks, procedure
definitions, procedure references, and module data. Later, the linker
can detect mismatches across compilation units by using this
information.
| -qextchk Option
|
-qflttrap
[=suboptions]
-qnoflttrap
|
FLTTRAP
[(suboptions)]
NOFLTTRAP
| Determines what types of floating-point exception conditions to detect at
run time. The program receives a SIGTRAP signal when the
corresponding exception occurs.
| -qflttrap Option
|
-qfullpath
-qnofullpath
|
| Records the full, or absolute, path names of source and include files in
object files compiled with debugging information (-g option).
| Default: | The relative path names of source files are recorded in the object
files.
|
| -qfullpath Option
|
| -qhalt=sev
| HALT(sev)
| Stops before producing any object, executable, or assembler source files
if the maximum severity of compile-time messages equals or exceeds the
specified severity. severity is one of i, l, w, e, s, u, or q, meaning informational, language, warning, error, severe error,
unrecoverable error, or a severity indicating "don't stop".
| -qhalt Option
|
-qinitauto[=hex_value]
-qnoinitauto
|
| Initializes each byte or word (4 bytes) of storage for automatic
variables to a specific value, depending on the length of the
hex_value. This helps you to locate variables that are
referenced before being defined. For example, by using both the -qinitauto option to initialize REAL variables with a NaNS
value and the -qflttrap option, it is possible to identify references to uninitialized
REAL variables at run time.
| Default: | -qnoinitauto. If you specify -qinitauto without a hex_value, the compiler
initializes the value of each byte of automatic storage to zero.
|
| -qinitauto Option
|
-qlanglvl={
77std
| 90std
| 90pure
| 90ext
| 95std
| 95pure
| extended}
|
LANGLVL({
77STD
| 90STD
| 90PURE
| 90EXT
| 95STD
| 95PURE
| EXTENDED})
| Determines which language standard (or superset or subset of a standard)
to consult for nonconformance. It identifies nonconforming source code and
also options that allow such nonconformances.
| Default: | -qlanglvl=extended.
|
| -qlanglvl Option
|
-qsaa
-qnosaa
|
SAA
NOSAA
| Checks for conformance to the SAA FORTRAN language definition. It
identifies nonconforming source code and also options that allow such
nonconformances.
| -qsaa Option
|
-qsigtrap[=
trap_handler]
|
| Installs xl_ _trce or a predefined or user-written
trap handler in a main program.
| Default: | No trap handler installed; program core dumps when a trap
instruction is executed.
|
| -qsigtrap Option
|
-qtbtable={none
| small
| full}
|
| Limits the amount of debugging traceback information in object files, to
reduce the size of the program.
| Default: | Full traceback information in the object file when compiling non-optimized
(without -O) or for debugging (with -g). Otherwise, small traceback information in the object
file.
|
| -qtbtable Option
|
-qwarn64
-qnowarn64
|
| Detects the truncation of an 8-byte integer pointer to 4 bytes.
Identifies statements that might cause problems during the 32-bit to 64-bit migration through
informational messages.
|
|
The following options determine whether the compiler produces a listing
(.lst file), what kinds of information go into the listing,
and what the compiler does about any error conditions it detects.
Some of the options in Options for Error Checking and Debugging can also produce compiler messages.
Figure 9. Options That Control Listings and Messages
| Command-Line Option
| @PROCESS Directive
| Description
| See Page
|
| -#
|
| Generates information on the progress of the compilation, without actually running the individual components.
| Default: | No progress messages are produced.
|
| -# Option
|
-qattr[=full]
-qnoattr
|
ATTR[(FULL)]
NOATTR
| Specifies whether to produce the attribute component of the attribute and
cross-reference section of the listing.
| -qattr Option
|
-qflag=
listing_severity:
terminal_severity
-w
|
FLAG
(listing_severity,
terminal_severity)
| Limits the diagnostic messages to those of a specified level or
higher. Only messages with severity listing_severity or higher
are written to the listing file. Only messages with severity
terminal_severity or higher are written to the terminal. -w is a short form for -qflag=e:e.
| -qflag Option
|
-qlist
-qnolist
|
LIST
NOLIST
| Specifies whether to produce the object section of the listing.
| -qlist Option
|
-qlistopt
-qnolistopt
|
LISTOPT
NOLISTOPT
| Determines whether to show the setting of every compiler option in the
listing file, or only selected options. These selected options include
those specified on the command line or directives, plus some that are
always put in the listing.
| -qlistopt Option
|
| -qnoprint
|
| Prevents the listing file from being created, regardless of the settings
of other listing options.
| Default: | Listing is produced if you specify any of -qattr, -qlist, -qlistopt,
-qphsinfo, -qreport, -qsource, or -qxref.
|
| -qnoprint Option
|
-qphsinfo
-qnophsinfo
|
PHSINFO
NOPHSINFO
| Determines whether timing information is displayed on the terminal for
each compiler phase.
| -qphsinfo Option
|
-qreport[={smplist
| hotlist}...]
-qnoreport
|
REPORT
[({SMPLIST |
HOTLIST}...)]
NOREPORT
| Determines whether to produce transformation reports showing how the
program is parallelized and how loops are optimized.
| -qreport Option
|
-qsource
-qnosource
|
SOURCE
NOSOURCE
| Determines whether to produce the source section of the listing.
| -qsource Option
|
-qxref
-qnoxref
-qxref=full
|
XREF
NOXREF
XREF(FULL)
| Determines whether to produce the cross-reference component of the
attribute and cross-reference section of the listing.
| -qxref Option
|
| -S
|
| Produces one or more .s files, showing equivalent
assembler source for each Fortran source file.
| Default: | The output is an executable file.
|
| -S Option
|
| -v
|
| Traces the progress of the compilation by displaying the name and
parameters of each compiler component that is executed by the invocation
command.
| Default: | No progress messages are produced.
|
| -v Option
|
| -V
|
| Traces the progress of the compilation by displaying the name and
parameters of each compiler component that is executed by the invocation
command. These are displayed in a shell-executable format.
| Default: | No progress messages are produced.
|
| -V Option
|
The following options help you maintain compatibility between your XL
Fortran source code on past, current, and future hardware platforms, or help
you port programs to XL Fortran with a minimum of changes.
The -qfree=ibm form of the -qfree Option also provides compatibility with VS FORTRAN free
form.
Figure 10. Options for Compatibility
| Command-Line Option
| @PROCESS Directive
| Description
| See Page
|
| -qautodbl=setting
| AUTODBL(setting)
| Provides an automatic means of converting single-precision floating-point
calculations to double-precision, and converting double-precision calculations
to extended-precision. Use one of the following settings: none, dbl, dbl4, dbl8, dblpad, dblpad4, or dblpad8.
| -qautodbl Option
|
-qctyplss
-qnoctyplss
|
CTYPLSS
NOCTYPLSS
| Specifies whether character constant expressions are allowed wherever
typeless constants may be used. This language extension might be needed when you are porting
programs from other platforms.
| -qctyplss Option
|
-qddim
-qnoddim
|
DDIM
NODDIM
| Specifies that the bounds of pointee arrays are re-evaluated each time
the arrays are referenced, and removes some restrictions on the bounds
expressions for pointee arrays.
| -qddim Option
|
-qdpc
-qdpc=e
-qnodpc
|
DPC
DPC(E)
NODPC
| Increases the precision of real constants, for maximum accuracy when
assigning real constants to DOUBLE PRECISION variables. This language extension might be needed when you are porting
programs from other platforms.
| -qdpc Option
|
-qescape
-qnoescape
|
ESCAPE
NOESCAPE
| Specifies how the backslash is treated in character strings, Hollerith
constants, H edit descriptors, and character string edit descriptors.
It can be treated as an escape character or as a backslash character.
This language extension might be needed when you are porting
programs from other platforms.
| -qescape Option
|
| -qextern=names
|
| Allows user-written procedures to be called instead of XL Fortran
intrinsics. names is a list of procedure names separated by
colons. The procedure names are treated as if they appear in an
EXTERNAL statement in each compilation unit being compiled.
If any of your procedure names conflict with XL Fortran intrinsic
procedures, use this option to call the procedures in the source code instead
of the intrinsic ones.
| Default: | Names of intrinsic procedures override user-written procedure names when they
are the same.
|
| -qextern Option
|
-qextname
-qnoextname
|
EXTNAME
NOEXTNAME
| Adds an underscore to the names of global entities, to help port programs
from systems where this is a convention for mixed-language programs.
| -qextname Option
|
-qintlog
-qnointlog
|
INTLOG
NOINTLOG
| Specifies that you can mix integer and logical values in expressions and
statements.
| -qintlog Option
|
| -qintsize=bytes
| INTSIZE(bytes)
| Sets the size of default INTEGER and LOGICAL
values.
| -qintsize Option
|
-qlog4
-qnolog4
|
LOG4
NOLOG4
| Specifies whether the result of a logical operation with logical operands
is a LOGICAL(4), or a LOGICAL with the maximum length of the
operands.
| -qlog4 Option
|
-qnullterm
-qnonullterm
|
NULLTERM
NONULLTERM
| Appends a null character to each character constant expression that is
passed as a dummy argument, to make it more convenient to pass strings to C
functions.
| -qnullterm Option
|
-1
-qonetrip
-qnoonetrip
|
ONETRIP
NOONETRIP
| Executes each DO loop in the compiled program at least once if
its DO statement is executed, even if the iteration count is
0.
| -1 Option
|
-qposition=
{appendold |
appendunknown}
|
POSITION(
{APPENDOLD |
APPENDUNKNOWN})
| Positions the file pointer at the end of the file when data is written
after an OPEN statement with no POSITION= specifier, and the
corresponding STATUS= value (OLD or UNKNOWN) is
specified.
| Default: | Depends on the I/O specifiers in the OPEN statement, and on the
compiler invocation command: -qposition=appendold for the xlf, xlf_r, xlf_r7, and
f77 commands, and the defined Fortran 90 and Fortran 95 behaviors for
the xlf90, xlf90_r, xlf90_r7, xlf95,
xlf95_r, and xlf95_r7 commands.
|
| -qposition Option
|
-qqcount
-qnoqcount
|
QCOUNT
NOQCOUNT
| Accepts the Q character-count edit descriptor (Q) as
well as the extended-precision Q edit descriptor
(Qw.d). With -qnoqcount, all Q edit descriptors are interpreted as the
extended-precision Q edit descriptor.
| -qqcount Option
|
| -qrealsize=bytes
| REALSIZE(bytes)
| Sets the default size of REAL, DOUBLE PRECISION,
COMPLEX, and DOUBLE COMPLEX values.
| -qrealsize Option
|
-qsave
-qnosave
|
SAVE
NOSAVE
| Specifies the default storage class for local variables: -qsave sets the default storage class to STATIC, while
-qnosave sets it to AUTOMATIC.
| Default: | -qnosave for the xlf90, xlf90_r, xlf90_r7, xlf95, xlf95_r, and
xlf95_r7 commands, and -qsave for the xlf, xlf_r, xlf_r7, and f77 commands.
|
| -qsave Option
|
-u
-qundef
-qnoundef
|
UNDEF
NOUNDEF
| Specifies whether implicit typing of variable names is permitted.
-u and -qundef have the same effect as the IMPLICIT NONE statement that
appears in each scope that allows implicit statements.
| -u Option
|
| -qxflag=oldtab
| XFLAG(OLDTAB)
| Interprets a tab in columns 1 to 5 as a single character (for fixed-form
programs), for compatibility with XL Fortran Version 1.
| Default: | Tab is interpreted as one or more characters.
|
| -qxflag=oldtab Option
|
| -qxlf77=settings
| XLF77(settings)
| Provides backward compatibility with the language from XL Fortran
Versions 1 and 2, for aspects of language semantics and I/O data format that
have changed. Most of these changes are required by the Fortran 90
standard.
| Default: | Default suboptions are blankpad, nogedit77, nointarg, nointxor, leadzero, nooldboz,
nopersistent, and nosofteof for the xlf90, xlf90_r, xlf90_r7, xlf95, xlf95_r, and
xlf95_r7 commands, and the exact opposite for the xlf, xlf_r, xlf_r7, and f77 commands.
|
| -qxlf77 Option
|
-qxlf90=
{[no]signedzero |
[no]autodealloc}
|
XLF90(
{[no]signedzero |
[no]autodealloc})
| Determines whether the compiler provides the Fortran 90 or the Fortran 95
level of support for certain aspects of the language.
| Default: | The default suboptions are signedzero and autodealloc for the xlf95, xlf95_r, and xlf95_r7 invocation
commands. For all other invocation commands, the default suboptions are
nosignedzero and noautodealloc.
|
| -qxlf90 Option
|
The following option is intended for writing new programs. It
changes the program in ways that would otherwise require source-code
changes.
Figure 11. Option for Fortran 90 Extensions
| Command-Line Option
| @PROCESS Directive
| Description
| See Page
|
| -qinit=f90ptr
| INIT(f90ptr)
| Makes the initial association status of pointers disassociated.
| Default: | The default association status of pointers is undefined.
|
| -qinit Option
|
To take maximum advantage of the system floating-point performance and
precision, you may need to specify details of how the compiler and
XLF-compiled programs perform floating-point calculations.
Figure 12. Options for Floating-Point Processing
| Command-Line Option
| @PROCESS Directive
| Description
| See Page
|
| -qfloat=options
| FLOAT(options)
| Determines how the compiler generates or optimizes code to handle
particular types of floating-point calculations.
| Default: | Default suboptions are nofltint, fold, nohsflt, nohssngl, nonans, norndsngl,
maf, norrm, and norsqrt; some of these settings are different with -O3
optimization turned on or with -qarch=ppc.
|
| -qfloat Option
|
-qieee={ Near
| Minus
| Plus
| Zero}
-y{n|m|p|z}
|
IEEE({Near
| Minus
| Plus
| Zero})
| Specifies the rounding mode for the compiler to use when evaluating
constant floating-point expressions at compile time.
| -qieee Option
|
The following options control the way the ld command processes
object files during compilation. Some of these options are passed on to
ld and are not processed by the compiler at all.
You can actually include ld options on the compiler command line,
because the compiler passes unrecognized options on to the linker.
In the table, an * indicates that the option is processed
by the ld command rather than the XL Fortran compiler; you can find
more information about these options in the AIX information for the
ld command.
| Related Information: | The -qextchk Option enables some extra consistency checking during
linking.
|
Other linker options you might find helpful are the following:
- -brename (to change individual symbol names to avoid unresolved
references)
- -bmap (to produce a map file showing information such as sizes of
common blocks).
Figure 13. Options That Control Linking
| Command-Line Option
| @PROCESS Directive
| Description
| See Page
|
| -b64*
|
| Instructs ld to bind 64-bit objects in 64-bit mode.
| -b64 Option
|
-bdynamic*
-bshared*
-bstatic*
|
| These options are toggles used to control the processing of -l options and the way that shared objects are processed.
| -bdynamic, -bshared, and -bstatic Options
|
| -bhalt:error_level*
|
| Specifies the maximum error level allowed before linker command processing
halts.
| Default: | -bhalt:4, as specified in the configuration file.
|
| -bhalt Option
|
| -bloadmap:name*
|
| Requests that a log of linker actions and messages be saved in file
name.
| -bloadmap Option
|
-bmaxdata:bytes*
-bmaxstack:bytes*
|
| Specifies the maximum amount of space to reserve for the program data
segment and stack segment, for programs where the size of these regions is a
constraint.
| Default: | Combined stack and data space is slightly less than 256 MB, or lower,
depending on the limits for the user ID.
|
| -bmaxdata, -bmaxstack Options
|
-brtl*
-bnortl*
|
| Determines which algorithm is used to find libraries (specified with the
-l option).
| -brtl Option
|
| -c
|
| Produces an object file instead of an executable file.
| Default: | Compile and link-edit, producing an executable file.
|
| -c Option
|
| -Ldir*
|
| Looks in the specified directory for libraries specified by the
-l option.
| -L Option
|
| -lkey*
|
| Searches the specified library file, where key selects the file
libkey.a.
| Default: | Libraries listed in xlf.cfg.
|
| -l Option
|
-qOBJect
-qNOOBJect
|
OBJect
NOOBJect
| Specifies whether to produce an object file, or stop immediately after
checking the syntax of the source files.
| -qobject Option
|
These options can help to do the following:
- Control internal size limits for the compiler.
- Determine names and options for commands that are executed during
compilation.
- Determine the bit mode and instruction set for the target
architecture.
Figure 14. Options That Control the Compiler Internal Operation
| Command-Line Option
| @PROCESS Directive
| Description
| See Page
|
| -Bprefix
|
| Determines a substitute path name for executable files used during
compilation, such as the compiler or linker. It can be used in
combination with the -t option, which determines which of these components are affected by
-B.
| Default: | Paths for these components are defined in the configuration file, the
$PATH environment variable, or both.
|
| -B Option
|
-Fconfig_file
-Fconfig_file:
stanza
-F:stanza
|
| Specifies an alternative configuration file, the stanza to use within the configuration file,
or both.
| Default: | The configuration file is /etc/xlf.cfg, and the stanza
depends on the name of the command that executes the compiler.
|
| -F Option
|
| -q32
|
| Sets the bit mode and instruction set for a 32-bit target
architecture.
| -q32 Option
|
| -q64
|
| Sets the bit mode and instruction set for a 64-bit target
architecture.
| -q64 Option
|
-qlm
-qnolm
|
| Disables the license management control.
| Default: | The license management control system (LM) is on by default. You must
specify the compiler option -qnolm to disable LM.
|
| -qlm Option
|
-NSbytes
-qSPILLsize=
bytes
|
SPILLsize
(bytes)
| Specifies the size of internal program storage areas.
| -N Option
|
-qmaxmem=
Kbytes
|
MAXMEM
(Kbytes)
| Limits the amount of memory that the compiler allocates while performing
specific, memory-intensive optimizations to the specified number of
kilobytes. A value of -1 allows optimization to take as much memory as
it needs without checking for limits.
| Default: | -qmaxmem=2048; -qmaxmem=-1 under -O3.
|
| -qmaxmem Option
|
| -tcomponents
|
| Applies the prefix specified by the -B option to the designated components. components
can be one or more of p, F, c, d, I, a, h, b, z, or l, with no
separators, corresponding to an optimizing preprocessor, the C preprocessor,
the compiler, the -S disassembler, the interprocedural analysis (IPA) tool, the
assembler, the loop optimizer, the code generator, the binder (fast linker),
and the linker, respectively.
| Default: | -B prefix, if any, applies to all components.
|
| -t Option
|
| -Wcomponent,options
|
| Passes the listed options to a component that is executed during
compilation. component is p, F, c, d, I, a, z, or l, corresponding to an optimizing preprocessor, the C
preprocessor, the compiler, the -S disassembler, the interprocedural analysis (IPA) tool, the
assembler, the binder (fast linker), and the linker, respectively.
| Default: | The options passed to these programs are as follows:
|
- Those listed in the configuration file.
- Any unrecognized options on the command line (passed to the
linker).
| -W Option
|
The following options are obsolete for either or both of the
following reasons:
- It has been replaced by an alternative that is considered better.
Usually this happens when a limited or special-purpose option is replaced by
one with a more general purpose and additional features.
- We expect that few or no customers use the feature, and that it can be
removed from the product in the future with minimal impact to current
users.
Notes:
- If you do use any of these options in existing makefiles or compilation
scripts, you should migrate to the new alternatives as soon as you can, to
avoid any potential problems in the future.
- The append suboption of -qposition has been replaced by appendunknown.
Figure 15. Options That Are Obsolete or Not Recommended
| Command-Line Option
| @PROCESS Directive
| Description
| See Page
|
-qcharlen=
length
|
CHARLEN
(length)
| Obsolete. It is still accepted, but has no effect. The maximum length for character constants and subobjects of
constants is 32 767 bytes (32 KB). The maximum length for character variables is
268 435 456 bytes (256 MB) in 32-bit mode. The
maximum length for character variables is 2**40 bytes in 64-bit mode. These limits are always in effect, and are intended to be high
enough to avoid portability problems with programs that contain long
strings.
| -qcharlen Option
|
-qrecur
-qnorecur
|
RECUR
NORECUR
| Not recommended. Specifies whether external subprograms may be
called recursively.
For new programs, use the RECURSIVE keyword, which provides a standard-conforming way of using
recursive procedures. If you specify the -qrecur option, the compiler must assume that any procedure could be
recursive. Code generation for recursive procedures may be less
efficient. Using the RECURSIVE keyword allows you to specify
exactly which procedures are recursive.
| -qrecur Option
|
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© Copyright IBM Corporation 1990, 1998.