CPU2006 Flag Description
Fujitsu Siemens Computers CELSIUS R550, Intel Xeon X5470 processor
Copyright © 2006 Intel Corporation. All Rights Reserved.
Base Portability Flags
-
- -DSPEC_CPU_LP64
![[suite]](http://www.spec.org/auto/cpu2006/flags/suite.png)
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -nofor_main
![[user]](http://www.spec.org/auto/cpu2006/flags/user.png)
- LDPORTABILITY
-
This option specifies that the main program is not written in Fortran.
It is a link-time option that prevents the compiler from linking for_main.o
into applications.
For example, if the main program is written in C and calls a Fortran subprogram,
specify -nofor-main when compiling the program with the ifort command.
If you omit this option, the main program must be a Fortran program.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -nofor_main
- LDPORTABILITY
-
This option specifies that the main program is not written in Fortran.
It is a link-time option that prevents the compiler from linking for_main.o
into applications.
For example, if the main program is written in C and calls a Fortran subprogram,
specify -nofor-main when compiling the program with the ifort command.
If you omit this option, the main program must be a Fortran program.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -nofor_main
- LDPORTABILITY
-
This option specifies that the main program is not written in Fortran.
It is a link-time option that prevents the compiler from linking for_main.o
into applications.
For example, if the main program is written in C and calls a Fortran subprogram,
specify -nofor-main when compiling the program with the ifort command.
If you omit this option, the main program must be a Fortran program.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
-
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
Peak Portability Flags
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -nofor_main
- LDPORTABILITY
-
This option specifies that the main program is not written in Fortran.
It is a link-time option that prevents the compiler from linking for_main.o
into applications.
For example, if the main program is written in C and calls a Fortran subprogram,
specify -nofor-main when compiling the program with the ifort command.
If you omit this option, the main program must be a Fortran program.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -nofor_main
- LDPORTABILITY
-
This option specifies that the main program is not written in Fortran.
It is a link-time option that prevents the compiler from linking for_main.o
into applications.
For example, if the main program is written in C and calls a Fortran subprogram,
specify -nofor-main when compiling the program with the ifort command.
If you omit this option, the main program must be a Fortran program.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -nofor_main
- LDPORTABILITY
-
This option specifies that the main program is not written in Fortran.
It is a link-time option that prevents the compiler from linking for_main.o
into applications.
For example, if the main program is written in C and calls a Fortran subprogram,
specify -nofor-main when compiling the program with the ifort command.
If you omit this option, the main program must be a Fortran program.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
- -DSPEC_CPU_LP64
- PORTABILITY
-
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.
-
-
Base Optimization Flags
-
- -fast
- OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
- -parallel
- Yes
- OPTIMIZE
-
Tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.
To use this option, you must also specify option O2 or O3. The default numbers of threads spawned is equal to
the number of processors detected in the system where the binary is compiled. Can be changed by setting the
environment variable OMP_NUM_THREADS
-
- -fast
- OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
- -parallel
- Yes
- OPTIMIZE
-
Tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.
To use this option, you must also specify option O2 or O3. The default numbers of threads spawned is equal to
the number of processors detected in the system where the binary is compiled. Can be changed by setting the
environment variable OMP_NUM_THREADS
-
- -fast
- OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
- -parallel
- Yes
- OPTIMIZE
-
Tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.
To use this option, you must also specify option O2 or O3. The default numbers of threads spawned is equal to
the number of processors detected in the system where the binary is compiled. Can be changed by setting the
environment variable OMP_NUM_THREADS
-
- -fast
- OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
- -parallel
- Yes
- OPTIMIZE
-
Tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.
To use this option, you must also specify option O2 or O3. The default numbers of threads spawned is equal to
the number of processors detected in the system where the binary is compiled. Can be changed by setting the
environment variable OMP_NUM_THREADS
Peak Optimization Flags
-
-
- -prof-use
- PASS2_CFLAGS, PASS2_LDFLAGS
-
Instructs the compiler to produce a profile-optimized
executable and merges available dynamic information (.dyn)
files into a pgopti.dpi file. If you perform multiple
executions of the instrumented program, -prof-use merges
the dynamic information files again and overwrites the
previous pgopti.dpi file.
Without any other options, the current directory is
searched for .dyn files
-
- -fast
- OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
-
-
-
- -opt-malloc-options=3
- COPTIMIZE
-
The compiler adds setup code in the C/C++/Fortran main function to enable optimal malloc algorithms:
n=0: Default, no changes to the malloc options. No call to mallopt() is made.
n=1: M_MMAP_MAX=2 and M_TRIM_THRESHOLD=0x10000000. Call mallopt with the two settings.
n=2: M_MMAP_MAX=2 and M_TRIM_THRESHOLD=0x40000000. Call mallopt with these two settings.
n=3: M_MMAP_MAX_=0 and M_TRIM_THRESHOLD=-1. Call mallopt with these two settings. This
will cause use of sbrk() calls instead of mmap() calls to get memory from the system.
Function: int mallopt (int param, int value) When calling mallopt, the param argument
specifies the parameter to be set, and value the new value to be set. Possible choices
for param, as defined in malloc.h, are:
M_TRIM_THRESHOLD This is the minimum size (in bytes) of the top-most, releasable chunk
that will cause sbrk to be called with a negative argument in order to return memory
to the system.
M_TOP_PAD This parameter determines the amount of extra memory to obtain from the system
when a call to sbrk is required. It also specifies the number of bytes to retain when
shrinking the heap by calling sbrk with a negative argument. This provides the necessary
hysteresis in heap size such that excessive amounts of system calls can be avoided.
M_MMAP_THRESHOLD All chunks larger than this value are allocated outside the normal heap,
using the mmap system call. This way it is guaranteed that the memory for these chunks
can be returned to the system on free. Note that requests smaller than this threshold
might still be allocated via mmap. M_MMAP_MAX The maximum number of chunks to allocate
with mmap. Setting this to zero disables all use of mmap.
-
- -fast
- OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
-
-
- -prof-use
- PASS2_CXXFLAGS, PASS2_LDFLAGS
-
Instructs the compiler to produce a profile-optimized
executable and merges available dynamic information (.dyn)
files into a pgopti.dpi file. If you perform multiple
executions of the instrumented program, -prof-use merges
the dynamic information files again and overwrites the
previous pgopti.dpi file.
Without any other options, the current directory is
searched for .dyn files
-
- -fast
- CXXOPTIMIZE, OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
-
- -auto-ilp32
- CXXOPTIMIZE
-
This option instructs the compiler to analyze and transform
the program so that 64-bit pointers are shrunk to 32-bit pointers,
and 64-bit longs (on Linux) are shrunk into 32-bit longs
wherever it is legal and safe to do so.
In order for this option to be effective the compiler must
be able to optimize using the -ipo/-Qipo option and must be able
to analyze all library/external calls the program makes.
This option requires that the size of the program executable
never exceeds 232 bytes and all data values
can be represented within 32 bits.
If the program can run correctly in a 32-bit system,
these requirements are implicitly satisfied.
If the program violates these size restrictions,
unpredictable behavior might occur.
-
-
- -prof-use
- PASS2_CXXFLAGS, PASS2_LDFLAGS
-
Instructs the compiler to produce a profile-optimized
executable and merges available dynamic information (.dyn)
files into a pgopti.dpi file. If you perform multiple
executions of the instrumented program, -prof-use merges
the dynamic information files again and overwrites the
previous pgopti.dpi file.
Without any other options, the current directory is
searched for .dyn files
-
- -fast
- CXXOPTIMIZE, OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
-
-
-
-
- -prof-use
- PASS2_CXXFLAGS, PASS2_LDFLAGS
-
Instructs the compiler to produce a profile-optimized
executable and merges available dynamic information (.dyn)
files into a pgopti.dpi file. If you perform multiple
executions of the instrumented program, -prof-use merges
the dynamic information files again and overwrites the
previous pgopti.dpi file.
Without any other options, the current directory is
searched for .dyn files
-
- -fast
- OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
- -opt-malloc-options=3
- OPTIMIZE
-
The compiler adds setup code in the C/C++/Fortran main function to enable optimal malloc algorithms:
n=0: Default, no changes to the malloc options. No call to mallopt() is made.
n=1: M_MMAP_MAX=2 and M_TRIM_THRESHOLD=0x10000000. Call mallopt with the two settings.
n=2: M_MMAP_MAX=2 and M_TRIM_THRESHOLD=0x40000000. Call mallopt with these two settings.
n=3: M_MMAP_MAX_=0 and M_TRIM_THRESHOLD=-1. Call mallopt with these two settings. This
will cause use of sbrk() calls instead of mmap() calls to get memory from the system.
Function: int mallopt (int param, int value) When calling mallopt, the param argument
specifies the parameter to be set, and value the new value to be set. Possible choices
for param, as defined in malloc.h, are:
M_TRIM_THRESHOLD This is the minimum size (in bytes) of the top-most, releasable chunk
that will cause sbrk to be called with a negative argument in order to return memory
to the system.
M_TOP_PAD This parameter determines the amount of extra memory to obtain from the system
when a call to sbrk is required. It also specifies the number of bytes to retain when
shrinking the heap by calling sbrk with a negative argument. This provides the necessary
hysteresis in heap size such that excessive amounts of system calls can be avoided.
M_MMAP_THRESHOLD All chunks larger than this value are allocated outside the normal heap,
using the mmap system call. This way it is guaranteed that the memory for these chunks
can be returned to the system on free. Note that requests smaller than this threshold
might still be allocated via mmap. M_MMAP_MAX The maximum number of chunks to allocate
with mmap. Setting this to zero disables all use of mmap.
-
-
- -prof-use
- PASS2_CXXFLAGS, PASS2_LDFLAGS
-
Instructs the compiler to produce a profile-optimized
executable and merges available dynamic information (.dyn)
files into a pgopti.dpi file. If you perform multiple
executions of the instrumented program, -prof-use merges
the dynamic information files again and overwrites the
previous pgopti.dpi file.
Without any other options, the current directory is
searched for .dyn files
-
- -fast
- CXXOPTIMIZE, OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
-
-
- -fast
- OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
-
- -parallel
- Yes
- OPTIMIZE
-
Tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.
To use this option, you must also specify option O2 or O3. The default numbers of threads spawned is equal to
the number of processors detected in the system where the binary is compiled. Can be changed by setting the
environment variable OMP_NUM_THREADS
-
-
- -prof-use
- PASS2_FFLAGS, PASS2_LDFLAGS
-
Instructs the compiler to produce a profile-optimized
executable and merges available dynamic information (.dyn)
files into a pgopti.dpi file. If you perform multiple
executions of the instrumented program, -prof-use merges
the dynamic information files again and overwrites the
previous pgopti.dpi file.
Without any other options, the current directory is
searched for .dyn files
-
- -fast
- OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
-
- -Ob0
- OPTIMIZE
-
Specifies the level of inline function expansion.
Ob0 - Disables inlining of user-defined functions. Note that
statement functions are always inlined.
Ob1 - Enables inlining when an inline keyword or an inline
attribute is specified. Also enables inlining according
to the C++ language.
Ob2 - Enables inlining of any function at the compiler's
discretion.
-
-
-
-
- -prof-use
- PASS2_FFLAGS, PASS2_LDFLAGS
-
Instructs the compiler to produce a profile-optimized
executable and merges available dynamic information (.dyn)
files into a pgopti.dpi file. If you perform multiple
executions of the instrumented program, -prof-use merges
the dynamic information files again and overwrites the
previous pgopti.dpi file.
Without any other options, the current directory is
searched for .dyn files
-
- -fast
- OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
-
- -prof-use
- PASS2_FFLAGS, PASS2_LDFLAGS
-
Instructs the compiler to produce a profile-optimized
executable and merges available dynamic information (.dyn)
files into a pgopti.dpi file. If you perform multiple
executions of the instrumented program, -prof-use merges
the dynamic information files again and overwrites the
previous pgopti.dpi file.
Without any other options, the current directory is
searched for .dyn files
-
- -fast
- OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
-
- -Ob0
- OPTIMIZE
-
Specifies the level of inline function expansion.
Ob0 - Disables inlining of user-defined functions. Note that
statement functions are always inlined.
Ob1 - Enables inlining when an inline keyword or an inline
attribute is specified. Also enables inlining according
to the C++ language.
Ob2 - Enables inlining of any function at the compiler's
discretion.
-
-
- -parallel
- Yes
- OPTIMIZE
-
Tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.
To use this option, you must also specify option O2 or O3. The default numbers of threads spawned is equal to
the number of processors detected in the system where the binary is compiled. Can be changed by setting the
environment variable OMP_NUM_THREADS
-
-
- -prof-use
- PASS2_FFLAGS, PASS2_LDFLAGS
-
Instructs the compiler to produce a profile-optimized
executable and merges available dynamic information (.dyn)
files into a pgopti.dpi file. If you perform multiple
executions of the instrumented program, -prof-use merges
the dynamic information files again and overwrites the
previous pgopti.dpi file.
Without any other options, the current directory is
searched for .dyn files
-
- -fast
- OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
-
-
-
- -prof-use
- PASS2_CFLAGS, PASS2_FFLAGS, PASS2_LDFLAGS
-
Instructs the compiler to produce a profile-optimized
executable and merges available dynamic information (.dyn)
files into a pgopti.dpi file. If you perform multiple
executions of the instrumented program, -prof-use merges
the dynamic information files again and overwrites the
previous pgopti.dpi file.
Without any other options, the current directory is
searched for .dyn files
-
- -fast
- OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
-
- -auto-ilp32
- COPTIMIZE
-
This option instructs the compiler to analyze and transform
the program so that 64-bit pointers are shrunk to 32-bit pointers,
and 64-bit longs (on Linux) are shrunk into 32-bit longs
wherever it is legal and safe to do so.
In order for this option to be effective the compiler must
be able to optimize using the -ipo/-Qipo option and must be able
to analyze all library/external calls the program makes.
This option requires that the size of the program executable
never exceeds 232 bytes and all data values
can be represented within 32 bits.
If the program can run correctly in a 32-bit system,
these requirements are implicitly satisfied.
If the program violates these size restrictions,
unpredictable behavior might occur.
-
-
- -prof-use
- PASS2_CFLAGS, PASS2_FFLAGS, PASS2_LDFLAGS
-
Instructs the compiler to produce a profile-optimized
executable and merges available dynamic information (.dyn)
files into a pgopti.dpi file. If you perform multiple
executions of the instrumented program, -prof-use merges
the dynamic information files again and overwrites the
previous pgopti.dpi file.
Without any other options, the current directory is
searched for .dyn files
-
- -fast
- OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
-
-
- -parallel
- Yes
- OPTIMIZE
-
Tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.
To use this option, you must also specify option O2 or O3. The default numbers of threads spawned is equal to
the number of processors detected in the system where the binary is compiled. Can be changed by setting the
environment variable OMP_NUM_THREADS
-
- -auto-ilp32
- COPTIMIZE
-
This option instructs the compiler to analyze and transform
the program so that 64-bit pointers are shrunk to 32-bit pointers,
and 64-bit longs (on Linux) are shrunk into 32-bit longs
wherever it is legal and safe to do so.
In order for this option to be effective the compiler must
be able to optimize using the -ipo/-Qipo option and must be able
to analyze all library/external calls the program makes.
This option requires that the size of the program executable
never exceeds 232 bytes and all data values
can be represented within 32 bits.
If the program can run correctly in a 32-bit system,
these requirements are implicitly satisfied.
If the program violates these size restrictions,
unpredictable behavior might occur.
-
- -fast
- OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
-
- -auto-ilp32
- COPTIMIZE
-
This option instructs the compiler to analyze and transform
the program so that 64-bit pointers are shrunk to 32-bit pointers,
and 64-bit longs (on Linux) are shrunk into 32-bit longs
wherever it is legal and safe to do so.
In order for this option to be effective the compiler must
be able to optimize using the -ipo/-Qipo option and must be able
to analyze all library/external calls the program makes.
This option requires that the size of the program executable
never exceeds 232 bytes and all data values
can be represented within 32 bits.
If the program can run correctly in a 32-bit system,
these requirements are implicitly satisfied.
If the program violates these size restrictions,
unpredictable behavior might occur.
-
- -fast
- OPTIMIZE
-
The -fast option enhances execution speed across the entire program
by including the following options that can improve run-time performance:
-O3 (maximum speed and high-level optimizations)
-ipo (enables interprocedural optimizations across files)
-xT (generate code specialized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad processors
and Intel(R) Xeon(R) processors with SSSE3)
-static
Statically link in libraries at link time
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
To override one of the options set by -fast, specify that option after the
-fast option on the command line. The exception is the xT option
which can't be overridden. The options set by -fast may change from
release to release.
- Includes:
-
- -parallel
- Yes
- OPTIMIZE
-
Tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.
To use this option, you must also specify option O2 or O3. The default numbers of threads spawned is equal to
the number of processors detected in the system where the binary is compiled. Can be changed by setting the
environment variable OMP_NUM_THREADS
-
-
- -auto-ilp32
- COPTIMIZE
-
This option instructs the compiler to analyze and transform
the program so that 64-bit pointers are shrunk to 32-bit pointers,
and 64-bit longs (on Linux) are shrunk into 32-bit longs
wherever it is legal and safe to do so.
In order for this option to be effective the compiler must
be able to optimize using the -ipo/-Qipo option and must be able
to analyze all library/external calls the program makes.
This option requires that the size of the program executable
never exceeds 232 bytes and all data values
can be represented within 32 bits.
If the program can run correctly in a 32-bit system,
these requirements are implicitly satisfied.
If the program violates these size restrictions,
unpredictable behavior might occur.
Implicitly Included Flags
This section contains descriptions of flags that were included implicitly
by other flags, but which do not have a permanent home at SPEC.
-
- -O3
-
Enables O2 optimizations plus more aggressive optimizations,
such as prefetching, scalar replacement, and loop and memory
access transformations. Enables optimizations for maximum speed,
such as:
- Loop unrolling, including instruction scheduling
- Code replication to eliminate branches
- Padding the size of certain power-of-two arrays to allow
more efficient cache use.
On systems using IA-32 architecture and Intel 64 architecture,
when O3 is used with options
-ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler
performs more aggressive data dependency analysis than for O2, which
may result in longer compilation times.
The O3 optimizations may not cause higher performance unless loop and
memory access transformations take place. The optimizations may slow
down code in some cases compared to O2 optimizations.
The O3 option is recommended for applications that have loops
that heavily use floating-point calculations
and process large data sets.
On Linux systems, the O3 option sets option
-fomit-frame-pointer.
- Includes:
-
- -O2
-
Enables optimizations for speed. This is the generally recommended
optimization level. This option also enables:
- Inlining of intrinsics
- Intra-file interprocedural optimizations, which include:
- inlining
- constant propagation
- forward substitution
- routine attribute propagation
- variable address-taken analysis
- dead static function elimination
- removal of unreferenced variables
- The following capabilities for performance gain:
- constant propagation
- copy propagation
- dead-code elimination
- global register allocation
- global instruction scheduling and control speculation
- loop unrolling
- optimized code selection
- partial redundancy elimination
- strength reduction/induction variable simplification
- variable renaming
- exception handling optimizations
- tail recursions
- peephole optimizations
- structure assignment lowering and optimizations
- dead store elimination
-
- -fomit-frame-pointer
-
This option determines whether EBP is used as a general-purpose
register in optimizations.
Option -fomit-frame-pointer allows this use.
Option -fno-omit-frame-pointer disallows it.
-
-
- -xT
-
Code is optimized for Intel(R) Core(TM)2 Duo processors, Intel(R) Core(TM)2 Quad
processors and Intel(R) Xeon(R) processors with SSSE3.
The resulting code may contain unconditional use of features that are not supported
on other processors. This option also enables new optimizations in addition to
Intel processor-specific optimizations including advanced data layout and code
restructuring optimizations to improve memory accesses for Intel processors.
Do not use this option if you are executing a program on a processor that
is not an Intel processor. If you use this option on a non-compatible processor
to compile the main program (in Fortran) or the function main() in C/C++, the
program will display a fatal run-time error if they are executed on unsupported
processors.
-
-
- -no-prec-div
-
(disable/enable[default] -prec-div)
-no-prec-div enables optimizations that give slightly less precise results
than full IEEE division.
When you specify -no-prec-div along with some optimizations, such as
-xN and -xB (Linux) or /QxN and /QxB (Windows),
the compiler may change floating-point division computations into
multiplication by the reciprocal of the denominator.
For example, A/B is computed as A * (1/B) to improve the speed of the
computation.
However, sometimes the value produced by this transformation is
not as accurate as full IEEE division. When it is important to have fully
precise IEEE division, do not use -no-prec-div which will enable the
default -prec-div and the result is more accurate, with some loss of
performance.
One or more of the following settings may have been set.
If so, the corresponding notes sections of the report will say so;
and you can read below to find out more about what these settings mean.
Environment Variables
OMP_NUM_THREADS
This Environment Variable
sets the maximum number of threads to use for OpenMP* parallel regions
if no other value is specified in the application.
This environment variable applies to both -openmp and -parallel
(Linux and Mac OS X) or /Qopenmp and /Qparallel (Windows).
Example syntax on a Linux system with 8 cores:
export OMP_NUM_THREADS=8
Default is the number of cores visible to the OS.
KMP_STACKSIZE
This Environment Variable specifies the stack size
to be allocated for each thread.
KMP_AFFINITY = < physical | logical >,starting-core-id
This Environment Variable specifies the static mapping
of user threads to physical cores, for example, if you have a system
configured with 8 cores, OMP_NUM_THREADS=8 and KMP_AFFINITY=physical,2.
Thread 0 will mapped to core 2, thread 1 will be mapped to core 3,
and so on in a round-robin fashion.
BIOS Settings
Hardware Prefetch:
This BIOS option allows the enabling/disabling of a processor
mechanism to prefetch data into the cache according to
a pattern-recognition algorithm.
In some cases, setting this option to Disabled may improve
performance. Users should only disable this option
after performing application benchmarking to verify improved
performance in their environment.
Adjacent Sector Prefetch:
This BIOS option allows the enabling/disabling of a processor
mechanism to fetch the adjacent cache line within an 128-byte
sector that contains
the data needed due to a cache line miss.
In some cases, setting this option to Disabled may improve
performance. Users should only disable this option
after performing application benchmarking to verify improved
performance in their environment.
Snoop Filter Enabled/Disabled:
The Snoop Filter is designed to reduce system bus utilization
coming from cache misses. On the Intel 5000X and 5400 chipset,
it is built as a cache structure able to minimize unnecessary
snoop traffic.
When enabled, it can lead to significant memory performance
improvements for several workstation applications
on suitable memory configurations.
C1 Enhanced Mode Enabled/Disabled:
The C1 Enhanced Mode reduces power consunmption of CPUs
in Halt state.
Linux commands
ulimit -s < n | unlimited >
This Linux command (a bash builtin command)
sets the stack size to n kbytes, or unlimited
to allow the stack size to grow without limit.
/usr/bin/taskset [options] [mask] [pid | command [arg] ... ]
This Linux command is used to set or retrieve the CPU affinity
of a running process given its PID or to launch a new COMMAND
with a given CPU affinity.
The option -c proclist or --cpu-list proclist
specifies a numerical list of processors to be used.
The list may contain multiple items, separated by comma,
and ranges. For example -c 0,5,7,9-11.
Example: /usr/bin/taskset -c 3 $command
executes $command on CPU 3.
SPEC config file feature submit
submit = /usr/bin/taskset -c $SPECCOPYNUM $command
When running multiple copies of benchmarks, the SPEC
config file feature submit is sometimes used
to cause individual jobs to be bound to specific processors.
This specific submit command is used for Linux.
The description of the elements of the command are:
- $command
Program to be started.
In this case, the benchmark instance to be started.
- $SPECCOPYNUM
Number of the benchmark instance to be started.
0 for the first instance, 1 for the second, and so on.
- /usr/bin/taskset
The Linux command taskset described above.
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 v1.1.
Report generated on Tue Jul 22 19:32:04 2014 by SPEC CPU2006 flags formatter v6906.
![[benchmark]](http://www.spec.org/auto/cpu2006/flags/benchmark.png)