IBM AIX Flag Disclosure
SPEC CPU2000
Last Revised 30 July, 2002
Source Level Portability Options
================================
-DHOST_WORDS_BIG_ENDIAN (176.gcc)
Host system is big-endian.
-DAIX (186.crafty)
Sets some basic parameters like endian-ess, OS type, and ANSI
language extensions to be compatible with an AIX system.
-DNDEBUG (252.eon)
SPEC default for C++ compiler but also needed explicitly by
some linkers. Defining this disables any assert macros used for
debugging.
-DNEED_EXPLICIT_SPECIALIZATION (252.eon)
Supply function definitions with explicit types in two cases
where templatized versions fail to compile.
-DSPEC_CPU2000_AIX (253.perlbmk)
Compile the SPEC CPU2000 modified perl for an AIX system.
-DSYS_IS_BSD (254.gap)
Compile gap for a BSDish system.
-DSYS_STRING_H (254.gap)
Do not explicitly include string.h
-DSYS_HAS_TIME_PROTO (254.gap)
Do not supply prototypes for the time(), times() and getrusage()
functions.
-DSYS_HAS_MALLOC_PROTO (254.gap)
Do not supply prototypes for malloc() and free().
-DSYS_HAS_CALLOC_PROTO (254.gap)
Do not supply a prototype for calloc().
-DHAVE_SIGNED_CHAR (300.twolf)
System allows signed char type.
Compiler Invocation
===================
xlc Invokes the compiler for C source files with a default language level
of ansi and specifies that it allow type-based aliasing.
cc Invokes the compiler for C source files with a default language of
extended and specifies that it provide compatibility with older IBM
compilers and allow placement of string literals or constant values in
read/write storage. cc does not conform to the ISO/ANSI C standard.
Compiler Options
================
-ma Use built-in alloca() function.
-O Performs optimizations that the compiler developers considered
the best combination for compilation speed and runtime
performance.
-O3 Perform some memory and compile time intensive optimizations in
addition to those executed with -O. The -O3 specific
optimizations have the potential to slightly alter the semantics
of a user's program. Optimizations may include, but are not
limited to: Aggressive code motion, and scheduling on
computations that have the potential to raise an exception;
Relaxed conformance to IEEE rules in cases where the difference
in the results is not important to an application; Rewriting of
floating point expressions.
-O4 Equivalent to -O3 -qipa -qhot with automatic generation of
architecture ( -qarch= )and tuning ( -qtune= )options ideal for
that platform. The qipa level defaults to level=1.
-O5 Equivalent to -O3 -qipa=level=2 -qhot with automatic generation
of architecture ( -qarch= ) and tuning ( -qtune= ) options ideal
for that platform.
-Q, -qinline The -Q option without any list inlines all appropriate
procedures, subject to limits on the number of inlined calls and
the amount of code size increase as a result. -qinline is an
alias for -Q.
-Q=xxx Inline all functions that contain less than xxx lines of
abstract code units.
-q64 Selects 64-bit compiler mode.
-qalign=natural The compiler maps structure members to their natural
boundaries.
-qansialias Use type-based aliasing during optimization
-qarch=ppc Produces object code containing instructions that will run on
any of the 32-bit PowerPC hardware platforms.
-qarch=pwr3 Produces object code containing instructions that will run on
power3 processors.
-qarch=rs64b Produces object code containing instructions that will run on
RS64-II processors.
-qdatalocal Changes the default to assume that all variables ar local.
-qessl Specifies that, if either -lessl or -lesslsmp are also
specified, then Engineering and Scientific Subroutine Library
(ESSL) routines should be used in place of some Fortran 90
intrinsic procedures when there is a safe opportunity to do so.
-qfixed Indicates that the input source program is in fixed form. Allows
fixed format Fortran 77 programs to be compiled using the xlf90
compiler invocation.
-qhot perform high-order transformations on loops during optimization.
-qipa=level=1 Turns on interprocedural analysis with inlining, limited alias
analysis, and limited call-site tailoring. This is the default
level of -qipa.
-qipa=level=2 Turns on interprocedural analysis with inlining, cloning, full
alias analysis, constant propagation, call-site tailoring, and
dead code removal.
-qinline Alias for -Q. See -Q.
-qipa=partition=large Specifies the size of the regions within the program to
analyze. Larger partitions contain more procedures,
which result in better interprocedural analysis but
require more storage to optimize.
-qlanglvl=ansi Compilation conforms to the ANSI standard.
-qpdf1/pdf2 Profile directed feedback optimization
-qsuffix=f=f90 Sets the suffix for source files to be .f90. The .f90 suffix is
required by xlf90 to compile Fortran 90 programs.
-qtune=604 Instruction selection, scheduling, and other implementation
dependent performance enhancements for the PowerPC 604/604e
processor.
-qtune=pwr3 Instruction selection, scheduling, and other implementation
dependent performance enhancements for the Power3 processor.
-qtune=rs64b Instruction selection, scheduling, and other implementation
dependent performance enhancements for the RS64-II processor.
-qunroll=n Unrolls inner loops in th program by a factor of n.
Linker Options
==============
-Ldir Link looks in the directory that is specified by the
option "dir".
-lessl Link the Engineering and Scientifc Subroutine Library (ESSL).
-lmass Link the mathematical acceleration subsystem libraries (MASS),
which contain libraries of tuned mathematical intrinsic
functions. See www.austin.ibm.com/tech/MASS.
-lhmu Link fast malloc libraries. These libraries are part of the
memdbg package that is included with IBM C compilers.
-lpdf Routines used in the first pass of the profile directed
feedback process. Routines from this library are not used in
building the final executable. In newer compilers, -qpdf1 does
this automatically, so using this in conjunction with -qpdf1
is redundant.
-blpdata Sets the bit in the file's XCOFF header indicating that this
executable will request the use of large pages when they are
available on the system and when the user has an appropriate
privilege
-bnso Brings referenced library procedures into the object file
-bI:/lib/syscalls.exp Create statically linked object files (syscalls.exp
supplies the names of the routines that can be
imported).
FDPR:
-----
The fdpr (feedback directed program restructuring) program optimizes the
executable image of a program by collecting information on the behavior of
the program while the program is used for some typical workload, and then
creating a new version. It is available on AIX Version 4 and 5 systems as part
of the Performance Toolbox for AIX.
Options:
-o OutFile Specifies the name of the output file from the optimizer.
-p ProgramName The name of the executable program to optimize.
-v Selects verbose output during processing/compilation
-x Command Specifies the command used for invoking the instrumented
program. All the arguments after the -x flag are used
for the invocation.
-R2 Employ a program-reordering technique in which the
original structure of the program, including traceback
entries, is preserved.
-R3 Employ global reordering techniques that do not preserve
debug information.
Large Page Settings :
-g Sets the page size for the large page
Example: -g 16777216 for 16M page
-L Sets the number of large pages
Example: -L 200 allows 200 large pages
-y1 Enables the memory affinity
chuser capabilities=CAP_BYPASS_RAC_VMM,CAP_PROPAGATE $USER
Allows $USER (non-root ID) to access the large pages that are available.