Compilers: IBM XL C/C++ Advanced Edition for Linux V9.0 and XL Fortran Advanced Edition for Linux V11.1
Operating systems: Red Hat Enterprise Linux Server release 5.1
![[user]](http://www.spec.org/auto/cpu2006/flags/user.png)
Invoke the IBM XL C compliler. 32-bit binaries are produced by default.
Support ISO C99 standard, and accepts implementation-specific language extensions.
Invoke the IBM XL C++ compliler. 32-bit binaries are produced by default.
Invoke the IBM XL C compliler. 32-bit binaries are produced by default.
Support ISO C99 standard, and accepts implementation-specific language extensions.
Invoke the IBM XL C++ compliler. 32-bit binaries are produced by default.
![[benchmark]](http://www.spec.org/auto/cpu2006/flags/benchmark.png)
This macro indicates that the benchmark is being compiled on a PowerPC system running the Linux operating system.
Portability changes for Linux
Causes the compiler to treat "char" variables as signed instead of the default of unsigned.
This flag can be set for SPEC compilation for Linux using default compiler.
This macro indicates that the benchmark is being compiled on a PowerPC system running the Linux operating system.
![[suite]](http://www.spec.org/auto/cpu2006/flags/suite.png)
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
Portability changes for Linux
Causes the compiler to treat "char" variables as signed instead of the default of unsigned.
This flag can be set for SPEC compilation for Linux using default compiler.
Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.
-O5 is equivalent to the following flags
qalias=ansi | noansi If ansi is specified, type-based aliasing is used during optimization, which restricts the lvalues that can be safely used to access a data object. The default is ansi for the xlc, xlC, and c89 commands. This option has no effect unless you also specify the -O option. qalias=std |nostd Indicates whether the compilation units contain any non-standard aliasing (see Compiler Reference for more information). If so, specify nostd.
Indicates that the compiler understands how to do alloca().
Link with libhugetlbfs.so. This enables heap to be backed by the 16 Megabyte pages.
Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.
-O5 is equivalent to the following flags
Cause the C++ compiler to generate Run Time Type Identification code for exception handling and for use by the typeid and dynamic_cast operators.
Link with MicroQuill's SmartHeap (32-bit) library for Linux on POWER. This is a library that optimizes calls to new, delete, malloc and free.
Pass the -q flag to the linker causing the final executable to have the relocation information.
The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both exectuion path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.
The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.
Perform optimizations for maximum performance. This includes interprocedural analysis on all of the objects presented on the "link" step.
-O4 is equivalent to the following flags
qalias=ansi | noansi If ansi is specified, type-based aliasing is used during optimization, which restricts the lvalues that can be safely used to access a data object. The default is ansi for the xlc, xlC, and c89 commands. This option has no effect unless you also specify the -O option. qalias=std |nostd Indicates whether the compilation units contain any non-standard aliasing (see Compiler Reference for more information). If so, specify nostd.
Link with MicroQuill's SmartHeap (32-bit) library for Linux on POWER. This is a library that optimizes calls to new, delete, malloc and free.
Pass the -q flag to the linker causing the final executable to have the relocation information.
The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both exectuion path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.
The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.
Perform optimizations for maximum performance. This includes interprocedural analysis on all of the objects presented on the "link" step.
-O4 is equivalent to the following flags
Link with libhugetlbfs.so. This enables heap to be backed by the 16 Megabyte pages.
Pass the -q flag to the linker causing the final executable to have the relocation information.
The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both exectuion path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.
The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.
Perform optimizations for maximum performance. This includes interprocedural analysis on all of the objects presented on the "link" step.
-O4 is equivalent to the following flags
Indicates that the compiler understands how to do alloca().
Generates 64 bit ABI binaries. The default is to generate 32 bit binaries.
Link with libhugetlbfs.so. This enables heap to be backed by the 16 Megabyte pages.
Pass the -q flag to the linker causing the final executable to have the relocation information.
Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.
-O5 is equivalent to the following flags
Disables generation of vector instructions for processors that support them.
Link with libhugetlbfs.so. This enables heap to be backed by the 16 Megabyte pages.
The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both exectuion path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.
The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.
Perform optimizations for maximum performance. This includes interprocedural analysis on all of the objects presented on the "link" step.
-O4 is equivalent to the following flags
Disables generation of vector instructions for processors that support them.
Link with libhugetlbfs.so. This enables heap to be backed by the 16 Megabyte pages.
Pass the -q flag to the linker causing the final executable to have the relocation information.
The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both exectuion path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.
The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.
Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.
-O5 is equivalent to the following flags
Disables generation of vector instructions for processors that support them.
Generates 64 bit ABI binaries. The default is to generate 32 bit binaries.
Link with libhugetlbfs.so. This enables heap to be backed by the 16 Megabyte pages.
Pass the -q flag to the linker causing the final executable to have the relocation information.
The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both exectuion path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.
The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.
Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.
-O5 is equivalent to the following flags
Generates 64 bit ABI binaries. The default is to generate 32 bit binaries.
Link with libhugetlbfs.so. This enables heap to be backed by the 16 Megabyte pages.
The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both exectuion path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.
The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.
Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.
-O5 is equivalent to the following flags
Cause the C++ compiler to generate Run Time Type Identification code for exception handling and for use by the typeid and dynamic_cast operators.
Link with MicroQuill's SmartHeap (32-bit) library for Linux on POWER. This is a library that optimizes calls to new, delete, malloc and free.
Pass the -q flag to the linker causing the final executable to have the relocation information.
The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both exectuion path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.
The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.
Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.
-O5 is equivalent to the following flags
Disables generation of vector instructions for processors that support them.
Link with MicroQuill's SmartHeap (32-bit) library for Linux on POWER. This is a library that optimizes calls to new, delete, malloc and free.
Pass the -q flag to the linker causing the final executable to have the relocation information.
Perform optimizations for maximum performance. This includes interprocedural analysis on all of the objects presented on the "link" step.
-O4 is equivalent to the following flags
Link with MicroQuill's SmartHeap (32-bit) library for Linux on POWER. This is a library that optimizes calls to new, delete, malloc and free.
Specifies whether to include standard object code in the object files. The noobject suboption can substantially reduce overall compilation time, by not generating object code during the first IPA phase. This option does not affect the code in the final binary created.
The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.
Specifies whether to include standard object code in the object files. The noobject suboption can substantially reduce overall compilation time, by not generating object code during the first IPA phase. This option does not affect the code in the final binary created.
The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.
Specifies whether to include standard object code in the object files. The noobject suboption can substantially reduce overall compilation time, by not generating object code during the first IPA phase. This option does not affect the code in the final binary created.
The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.
Specifies whether to include standard object code in the object files. The noobject suboption can substantially reduce overall compilation time, by not generating object code during the first IPA phase. This option does not affect the code in the final binary created.
The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.
This section contains descriptions of flags that were included implicitly by other flags, but which do not have a permanent home at SPEC.
Perform optimizations for maximum performance. This includes interprocedural analysis on all of the objects presented on the "link" step.
-O4 is equivalent to the following flags
Performs additional optimizations that are memory intensive, compile-time intensive, and may change the semantics of the program slightly, unless -qstrict is specified. We recommend these optimizations when the desire for run-time speed improvements outweighs the concern for limiting compile-time resources.
-O3 is equivalent to the following flags
Performs high-order transformations on loops during optimization.
Enhances optimization by doing detailed analysis across procedures (interprocedural analysis or IPA). The level determines the amount of interprocedural analysis and optimization that is performed.
level=0 Does only minimal interprocedural analysis and optimization
level=1 turns on inlining , limited alias analysis, and limited call-site tailoring
level=2 turns on full interprocedural data flow and alias analysis
Produces object code containing instructions that will run on the specified processors. "auto" selects the processor the complile is being done on. "pwr5x" is the POWER5+ processor.
Supported values for this flag are
Specifies the architecture system for which the executable program
is optimized. This includes instruction scheduling and cache setting.
The supported values for suboption are:
Enhances optimization by doing detailed analysis across procedures (interprocedural analysis or IPA). The level determines the amount of interprocedural analysis and optimization that is performed.
level=0 Does only minimal interprocedural analysis and optimization
level=1 turns on inlining , limited alias analysis, and limited call-site tailoring
level=2 turns on full interprocedural data flow and alias analysis
echo 200 > /proc/sys/vm/nr_hugepages
Usage: chsyscfg -r lpar | prof | sys | sysprof | frame
-m <managed system> | -e <managed frame>
-f <configuration file> | -i "<configuration data>"
[--help]
Changes partitions, partition profiles, system profiles, or the attributes of a
managed system or a managed frame.
-r - the type of resource(s) to be changed:
lpar - partition
prof - partition profile
sys - managed system
sysprof - system profile
frame - managed frame
-m <managed system> - the managed system's name
-e <managed frame> - the managed frame's name
-f <configuration file> - the name of the file containing the
configuration data for this command.
The format is:
attr_name1=value,attr_name2=value,...
or
"attr_name1=value1,value2,...",...
-i "<configuration data>" - the configuration data for this command.
The format is:
"attr_name1=value,attr_name2=value,..."
or
""attr_name1=value1,value2,...",..."
--help - prints this help
The valid attribute names for this command are:
-r prof required: name, lpar_id | lpar_name
optional: ...
lpar_proc_compat_mode (default | POWER6_enhanced)
submit = numactl --membind=\$SPECCOPYNUM --physcpubind=\$SPECCOPYNUM $command
--membind=nodes
Only allocate memory from nodes. Allocation will fail when
there is not enough memory available on these nodes.
--physcpubind=cpus
Only execute process on cpus. This accepts physical cpu numbers
as shown in the processor fields of /proc/cpuinfo.
HUGETLB_VERBOSE=0 : Turn off any debugging message from libhugetlbfs HUGETLB_MORECORE=yes: Instructs libhugetlbfs to override libc's normal morecore() function with a hugepage version and use it for malloc(). HUGETLB_MORECORE_HEAPBASE=0x50000000: Specifies that the hugepage heap address to start at 0x50000000. XLFRTEOPTS=intrinthrds=1 : Causes the Fortran runtime to only use a single thread.
- First we copied the original executable (baseexe) to baseexe.orig.
- Then, the executable is instrumented and its initial profile generated, as follows:
$ fdprpro -a instr baseexe
The output will be generated (by default) in baseexe.instr and its profile in baseexe.nprof.
- Next, run baseexe.instr using the training data. This will fill the profile file with information that characterizes the training workload.
- Finally, re-run FDPR-Pro with the profile file provided, as follows:
$ fdprpro -a opt -f baseexe.nprof [optimization options] baseexe
- We use the following optimization options : -q -O4 -A 32 -shci 90 -sdp 9
Optimization Options Descriptions:
-A alignment, --align-code alignment
Align program code so that hot code will be aligned on alignment-byte addresses.
-abb factor, --align-basic-blocks factor
Align basic blocks that are hotter then the average by given (float) factor. This is a lower-level
machine-specific alignment compared to --align-code. Value of -1 (the default) disables this option.
-bf, --branch-folding
Eliminate branch to branch instructions.
-bp, --branch-prediction
Set branch prediction bit for conditional branches.
-dce, --dead-code-elimination
Eliminate instructions related to unused local variables within frequently executed functions (useful
mainly after applying function inlining optimization).
-dp, --data-prefetch
Insert dcbt instructions to improve data-cache performance.
-ece, --epilog-code-eliminate
Reduce code size by grouping common instructions in functions' epilogs, into a single unified code.
-hr, --hco-reschedule
Relocate instructions from frequently executed code to rarely executed code areas, when possible.
-hrf factor, --hco-resched-factor factor
Set the aggressiveness of the -hr optimization option according to a factor value between (0,1), where
0 is the least aggressive factor (applicable only with the -hr option).
-i, --inline
Same as --selective-inline with --inline-small-funcs 12.
-ihf pct, --inline-hot-functions pct
Inline all function call sites to functions that have a frequency count greater than the given pct
frequency percentage.
-isf size, --inline-small-funcs size
Inline all functions that are smaller or equal to the given size in bytes.
-kr, --killed-registers
Eliminate stores and restores of registers that are killed (overwritten) after frequently executed
function calls.
-lap, --load-address-propagation
Eliminate load instructions of variables' addresses by re-using pre-loaded addresses of adjacent vari-
ables.
-las, --load-after-store
Add NOP instructions to place each load instruction further apart following a store instruction that
reference the same memory address.
-lro, --link-register-optimization
Eliminate saves and restores of the link register in frequently-executed functions.
-lu aggressiveness_factor, --loop-unroll aggressiveness_factor
Unroll short loops containing of one to several basic blocks according to an aggressiveness factor
between (1,9), where 1 is the least aggressive unrolling option for very hot and short loops.
-lun unrolling_number, --loop-unrolling-number unrolling_number
Set the number of unrolled iterations in each unrolled loop. The allowed range is between (2,50).
Default is set to 2. (applicable only with the -lu flag).
-nop, --nop-removal
Remove NOP instructions from reordered code.
-O Switch on basic optimizations only. Same as -RC -nop -bp -bf.
-O2 Switch on less aggressive optimization flags. Same as -O -hr -pto -isf 8 -tlo -kr.
-O3 Switch on aggressive optimization flags. Same as -O2 -RD -isf 12 -si -dp -lro -las -vro -btcar -lu 9
-rt 0 -pbsi.
-O4 Switch on aggressive optimization flags together with aggressive function inlining. Same as -O3 -sidf
50 -ihf 20 -sdp 9 -shci 90 and -bldcg (for XCOFF files).
-O5 Switch on aggressive optimization flags together with HLR optimization. Same as -O4 -sa -gcpyp -gcnstp
-dce.
-pbsi, --path-based-selective-inline
Perform selective inlining of dominant hot function calls based on control flow paths leading to hot
functions.
-pca, --propagate-constant-area
Relocate the constant variables area to the top of the code section when possible.
-[no]pr, --[no]ptrgl-r11
Perform removal of R11 load instruction in _ptrgl csect.
-pto, --ptrgl-optimization
Perform optimization of indirect call instructions via registers by replacing them with conditional
direct jumps.
-ptosl limit_size, --ptrgl-optimization-size-limit limit_size
Set the limit of the number of conditional statements generated by -pto optimization. Allowed values
are between 1..100. Default value set to 3. (applicable only with the -pto flag).
-ptoht heatness_threshold, --ptrgl-optimization-heatness-threshold heatness_threshold
Set the frequency threshold for indirect calls that are to be optimized by -pto optimization. Allowed
range between 0..1. Default is set to 0.8. (applicable only with -pto flag).
-RC, --reorder-code
Perform code reordering.
-rcaf aggressiveness_factor, --reorder-code-aggressivenes-factor aggressiveness_factor
Set the aggressiveness of code reordering optimization. Allowed values are [0 | 1 | 2], where 0 pre-
serves original code order and 2 is the most aggressive. Default is set to 1. (applicable only with
the -RC flag).
-rcctf termination_factor, --reorder-code-chain-termination-factor termination_factor
Set the threshold fraction which determines when to terminate each chain of basic blocks during code
reordering. Allowed input range is between 0.0 to 1.0 where 0.0 generates long chains and 1.0 creates
single basic block chains. Default is set to 0.05. (applicable only with the -RC flag).
-rccrf reversal_factor, --reorder-code-condition-reversal-factor reversal_factor
Set the threshold fraction which determines when to enable condition reversal for each conditional
branch during code reordering. Allowed input range is between 0.0 to 1.0 when 0.0 tries to preserve
original condition direction and 1.0 ignores it. Default is set to 0.8 (applicable only with the -RC
flag).
-RD, --reorder-data
Perform static data reordering.
-rmte, --remove-multiple-toc-entries
Remove multiple TOC entries pointing to the same location in the input program file.
-rt removal_factor, --reduce-toc removal_factor
Perform removal of TOC entries according to a removal factor between (0,1), where 0 removes non-
accessed TOC entries only, and 1 removes all possible TOC entries.
-sdp aggressiveness_factor, --stride-data-prefetch aggressiveness_factor
Perform data prefetching within frequently executed loops based on stride analysis, according to an
aggressiveness factor between (1,9), where 1 is least aggressive.
-sdpla iterations_number, --stride-data-prefetch-look-ahead iterations_number
Set the number of iterations for which data is prefetched into the cache ahead of time. Default value
is set to 4 iterations. (applicable only with the -sdp flag).
-sdpms stride_min_size, --stride-data-prefetch-min-size stride_min_size
Set the minimal stride size in bytes, for which data will be considered as a candidate for prefetch-
ing. Default value is set to 128 bytes. (applicable only with the -sdp flag).
-shci pct, --selective-hot-code-inline pct
Perform selective inlining of functions in order to decrease the total number of execution counts, so
that only functions whose hotness is above the given percentage are inlined.
-si, --selective-inline
Perform selective inlining of dominant hot function calls.
-sll Lib1:Prof1,...,LibN:ProfN, --static-link-libraries Lib1:Prof1,...,LibN:ProfN
Statically link hot code from specified dynamically linked libraries to the input program. The parame-
ter consists of comma-separated list of libraries and their profiles. IMPORTANT: licensing rights of
specified libraries should be observed when applying this copying optimization.
-sllht hotness_threshold, --static-link-libraries-hotness-threshold hotness_threshold
Set hotness threshold for the --static-link-libraries optimization. The allowed input range is between
0 (least aggressive) to 1, or -1, which does not require profile and selects all code that might be
called by the input program from the given libraries. Default is 0.5.
-sidf percentage_factor, --selective-inline-dominant-factor percentage_factor
Set a dominant factor percentage for selective inline optimization. The allowed range is between
(0,100). Default is set to 80 (applicable only with the -si and -pbsi flags).
-siht frequency_factor, --selective-inline-hotness-threshold frequency_factor
Set a hotness threshold factor percentage for selective inline optimization to inline all dominant
function calls that have a frequency count greater than the given frequency percentage. Default is set
to 100 (applicable only with the -si -pbsi flags).
-so, --stack-optimization
Reduce the stack frame size of functions which are called with a small number of arguments.
-tb, --preserve-traceback-tables
Force the restructuring of traceback tables in reordered code. If -tb option is omitted, traceback
tables are automatically included only for C++ applications which use the Try & Catch mechanism.
-rtb, --remove-traceback-tables
Remove traceback tables in reordered code.
-tlo, --tocload-optimization
Replace each load instruction that references the TOC with a corresponding add-immediate instruction
via the TOC anchor register, when possible.
-vro, --volatile-registers-optimization
Eliminate stores and restores of non-volatile registers in frequently executed functions by using
available volatile registers.
Flag description origin markings:
|
Indicates that the flag description came from the user flags file. |
|
Indicates that the flag description came from the suite-wide flags file. |
|
Indicates that the flag description came from a per-benchmark flags file. |
For questions about the meanings of these flags, please contact the tester.
For other inquiries, please contact webmaster@spec.org
Copyright 2006-2014 Standard Performance Evaluation Corporation
Tested with SPEC CPU2006 v1.0.
Report generated on Tue Jul 22 14:23:12 2014 by SPEC CPU2006 flags formatter v6906.