CPU2017 Flag Description
Dell Inc. PowerEdge R7425 (AMD EPYC 7251, 2.10 GHz
This result has been formatted using multiple flags files.
The "default header section" from each of them appears next.
Default header section from aocc100-flags-revC-I
AMD Optimizing C/C++ Compiler Suite SPEC CPU2017 Flag Description
Compilers: AOCC Suite
Default header section from gcc
GNU Compiler Collection Flags
Flag descriptions for GCC, the GNU Compiler Collection
Note: The GNU Compiler Collection provides a wide array of compiler options, described in detail and readily
available at
https://gcc.gnu.org/onlinedocs/gcc/Option-Index.html#Option-Index and https://gcc.gnu.org/onlinedocs/gfortran/. This SPEC CPU flags file
contains excerpts from and brief summaries of portions of that documentation.
SPEC's modifications are:
Copyright (C) 2006-2017 Standard Performance Evaluation Corporation
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License,
Version 1.3 or any later version published by the Free Software Foundation; with the Invariant Sections being "Funding Free
Software", the Front-Cover Texts being (a) (see below), and with the Back-Cover Texts being (b) (see below). A copy of the
license is included in your SPEC CPU kit at $SPEC/Docs/licenses/FDL.v1.3 and on the web at http://www.spec.org/cpu2017/Docs/licenses/FDL.v1.3.
A copy of "Funding Free Software" is on your SPEC CPU kit at $SPEC/Docs/licenses/FundingFreeSW and on the web at http://www.spec.org/cpu2017/Docs/licenses/FundingFreeSW.
(a) The FSF's Front-Cover Text is:
A GNU Manual
(b) The FSF's Back-Cover Text is:
You have freedom to copy and modify this GNU Manual, like GNU software. Copies published by the Free
Software Foundation raise funds for GNU development.
Base Compiler Invocation
-
- clang
![[user]](https://www.spec.org/auto/cpu2017/images/user.png)
- CC, LD
-
clang is a C, C++, and Objective-C compiler which encompasses preprocessing, parsing, optimization, code generation,
assembly, and linking. Depending on which high-level mode setting is passed, Clang may stop before doing a full
link.
-
- clang++
- CXX, LD
-
clang is a C, C++, and Objective-C compiler which encompasses preprocessing, parsing, optimization, code generation,
assembly, and linking. Depending on which high-level mode setting is passed, Clang may stop before doing a full
link.
-
- clang
- LD
-
clang is a C, C++, and Objective-C compiler which encompasses preprocessing, parsing, optimization, code generation,
assembly, and linking. Depending on which high-level mode setting is passed, Clang may stop before doing a full
link.
-
Peak Compiler Invocation
-
- clang
- CC, LD
-
clang is a C, C++, and Objective-C compiler which encompasses preprocessing, parsing, optimization, code generation,
assembly, and linking. Depending on which high-level mode setting is passed, Clang may stop before doing a full
link.
-
- clang++
- CXX, LD
-
clang is a C, C++, and Objective-C compiler which encompasses preprocessing, parsing, optimization, code generation,
assembly, and linking. Depending on which high-level mode setting is passed, Clang may stop before doing a full
link.
-
- clang
- LD
-
clang is a C, C++, and Objective-C compiler which encompasses preprocessing, parsing, optimization, code generation,
assembly, and linking. Depending on which high-level mode setting is passed, Clang may stop before doing a full
link.
-
Base Portability Flags
-
![[suite]](https://www.spec.org/auto/cpu2017/images/suite.png)
- EXTRA_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.
-
- EXTRA_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.
-
- EXTRA_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.
-
-
- EXTRA_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.
-
- EXTRA_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.
-
- EXTRA_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.
-
- EXTRA_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.
-
- EXTRA_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.
-
- EXTRA_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
-
- EXTRA_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.
-
- EXTRA_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.
-
- EXTRA_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.
-
- EXTRA_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.
-
- EXTRA_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.
-
- EXTRA_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.
-
- EXTRA_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
-
-
-
-
-
- -O3
- COPTIMIZE
-
Like -O2, except that it enables optimizations that take longer to perform or that may generate larger code (in an
attempt to make the program run faster).
If multiple "O" options are used, with or without level numbers, the last such option is the one that is effective.
- Includes:
-
- -ffast-math
- COPTIMIZE
-
Enables a range of optimizations that provide faster, though sometimes less precise, mathematical operations that may
not conform to the IEEE-754 specifications. When this option is specified, the __STDC_IEC_559__ macro is
ignored even if set by the system headers.
-
- -march=znver1
- COPTIMIZE
-
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify
-march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but
which may not exist on earlier products.
-
-
-
-
-
-
-
-
-
-
-
-
-
- -O3
- CXXOPTIMIZE
-
Like -O2, except that it enables optimizations that take longer to perform or that may generate larger code (in an
attempt to make the program run faster).
If multiple "O" options are used, with or without level numbers, the last such option is the one that is effective.
- Includes:
-
- -march=znver1
- CXXOPTIMIZE
-
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify
-march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but
which may not exist on earlier products.
-
-
-
-
-
-
-
-
-
-
-
-
- -O3
- FOPTIMIZE
-
Like -O2, except that it enables optimizations that take longer to perform or that may generate larger code (in an
attempt to make the program run faster).
If multiple "O" options are used, with or without level numbers, the last such option is the one that is effective.
- Includes:
-
-
-
-
- -ffast-math
- FOPTIMIZE
-
Enables a range of optimizations that provide faster, though sometimes less precise, mathematical operations that may
not conform to the IEEE-754 specifications. When this option is specified, the __STDC_IEC_559__ macro is
ignored even if set by the system headers.
-
-
-
-
-
-
-
-
-
-
-
-
Peak Optimization Flags
-
-
-
-
-
-
-
- -march=znver1
- COPTIMIZE
-
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify
-march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but
which may not exist on earlier products.
-
-
-
-
-
-
-
-
- -m32
- CC, LD
-
Generate code for a 32-bit environment. The 32-bit environment sets int, long and
pointer to 32 bits and generates code that runs on any i386 system. The compiler generates x86 or IA32
32-bit ABI. The default on a 32-bit host is 32-bit ABI. The default on a 64-bit host is 64-bit ABI if the target
platform specified is 64-bit, otherwise the default is 32-bit.
-
-
-
-
-
- -march=znver1
- COPTIMIZE
-
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify
-march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but
which may not exist on earlier products.
-
-
-
-
-
-
-
- EXTRA_COPTIMIZE
-
Tells GCC to use the GNU semantics for "inline" functions, that is, the behavior prior to the C99 standard.
This switch may resolve duplicate symbol errors, as noted in the 502.gcc_r benchmark description.
-
-
-
-
-
-
- -march=znver1
- COPTIMIZE
-
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify
-march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but
which may not exist on earlier products.
-
-
-
-
-
-
-
-
-
-
-
-
- -march=znver1
- CXXOPTIMIZE
-
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify
-march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but
which may not exist on earlier products.
-
-
-
-
-
-
- -m32
- CXX, LD
-
Generate code for a 32-bit environment. The 32-bit environment sets int, long and
pointer to 32 bits and generates code that runs on any i386 system. The compiler generates x86 or IA32
32-bit ABI. The default on a 32-bit host is 32-bit ABI. The default on a 64-bit host is 64-bit ABI if the target
platform specified is 64-bit, otherwise the default is 32-bit.
-
-
-
-
-
- -march=znver1
- CXXOPTIMIZE
-
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify
-march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but
which may not exist on earlier products.
-
-
-
-
-
-
-
-
-
-
-
-
- -march=znver1
- CXXOPTIMIZE
-
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify
-march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but
which may not exist on earlier products.
-
-
-
-
-
-
-
- -O3
- FOPTIMIZE
-
Like -O2, except that it enables optimizations that take longer to perform or that may generate larger code (in an
attempt to make the program run faster).
If multiple "O" options are used, with or without level numbers, the last such option is the one that is effective.
- Includes:
-
-
-
-
- -ffast-math
- FOPTIMIZE
-
Enables a range of optimizations that provide faster, though sometimes less precise, mathematical operations that may
not conform to the IEEE-754 specifications. When this option is specified, the __STDC_IEC_559__ macro is
ignored even if set by the system headers.
-
-
-
-
-
-
-
-
-
-
-
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.
-
- -O2
-
Moderate level of optimization which enables most optimizations. This is the default when no "-O" option is specified,
or if no value is specified (i.e. "-O").
If multiple "O" options are used, with or without level numbers, the last such option is the one that is effective.
- Includes:
-
- -O1
-
Somewhere between -O0 and -O2.
If multiple "O" options are used, with or without level numbers, the last such option is the one that is effective.
This result has been formatted using multiple flags files.
The "submit command" from each of them appears next.
Submit command from aocc100-flags-revC-I
AMD Optimizing C/C++ Compiler Suite SPEC CPU2017 Flag Description
Using numactl to bind processes and memory to cores
For multi-copy runs or single copy runs on systems with multiple sockets, it is advantageous to bind a process to a
particular core. Otherwise, the OS may arbitrarily move your process from one core to another. This can affect
performance. To help, SPEC allows the use of a "submit" command where users can specify a utility to use to bind
processes. We have found the utility 'numactl' to be the best choice.
numactl runs processes with a specific NUMA scheduling or memory placement policy. The policy is set for a
command and inherited by all of its children. The numactl flag "--physcpubind" specifies
which core(s) to bind the process. "-l" instructs numactl to keep a process's memory on the
local node while "-m" specifies which node(s) to place a process's memory. For full details on using
numactl, please refer to your Linux documentation, 'man numactl'
Note that some older versions of numactl incorrectly interpret application arguments as its own. For
example, with the command "numactl --physcpubind=0 -l a.out -m a", numactl will interpret
a.out's "-m" option as its own "-m" option. To work around this problem, we put
the command to be run in a shell script and then run the shell script using numactl. For example:
"echo 'a.out -m a' > run.sh ; numactl --physcpubind=0 bash run.sh"
Submit command from gcc
GNU Compiler Collection Flags
SPECrate runs might use one of these methods to bind processes to specific processors, depending on the config file.
Linux systems: the numactl command is commonly used. Here is a brief guide to understanding the specific
command which will be found in the config file:
- syntax: numactl [--interleave=nodes] [--preferred=node] [--physcpubind=cpus] [--cpunodebind=nodes]
[--membind=nodes] [--localalloc] command args ...
- numactl runs processes with a specific NUMA scheduling or memory placement policy. The policy is set for a
command and inherited by all of its children.
- --localalloc instructs numactl to keep a process memory on the local node while -m specifies which node(s) to
place a process memory.
- --physcpubind specifies which core(s) to bind the process. In this case, copy 0 is bound to processor 0
etc.
- For full details on using numactl, please refer to your Linux documentation, man numactl
Solaris systems: The pbind command is commonly used, via
submit=echo 'pbind -b...' > dobmk; sh dobmk
The specific command may be found in the config file; here is a brief guide to understanding that command:
- submit= causes the SPEC tools to use this line when submitting jobs.
- echo ...> dobmk causes the generated commands to be written to a file, namely
dobmk.
pbind -b causes this copy's processes to be bound to the CPU specified by the expression that
follows it. See the config file used in the run for the exact syntax, which tends to be cumbersome because of
the need to carefully quote parts of the expression. When all expressions are evaluated, the jobs are typically
distributed evenly across the system, with each chip running the same number of jobs as all other chips, and each
core running the same number of jobs as all other cores.
The pbind expression may include various elements from the SPEC toolset and from standard Unix commands, such
as:
- $BIND: a reference to a value from the bind line, a line of the form
"bind = n n n n", where each "n" is a processor number. See http://www.spec.org/cpu2017/Docs/config.html#bind
for details on this feature.
- $$: the current process id
- $SPECCOPYNUM: the SPEC tools-assigned number for this copy of the benchmark.
- psrinfo: find out what processors are available
- grep on-line: search the psrinfo output for information regarding on-line cpus
- expr: Calculate simple arithmetic expressions. For example, the effect of binding jobs to a
(quote-resolved) expression such as:
expr ( $SPECCOPYNUM / 4 ) * 8 + ($SPECCOPYNUM % 4 ) )
would be to send the jobs to processors whose numbers are:
0,1,2,3, 8,9,10,11, 16,17,18,19 ...
- awk...print \$1: Pick out the line corresponding to this copy of the benchmark and use the CPU
number mentioned at the start of this line.
- sh dobmk actually runs the benchmark.
No special commands are needed for feedback-directed optimization, other than the compiler profile flags.
This result has been formatted using multiple flags files.
The "sw environment" from each of them appears next.
Sw environment from aocc100-flags-revC-I
AMD Optimizing C/C++ Compiler Suite SPEC CPU2017 Flag Description
Transparent Huge Pages (THP)
THP is an abstraction layer that automates most aspects of creating, managing, and using huge pages. THP is designed
to hide much of the complexity in using huge pages from system administrators and developers, as normal huge pages
must be assigned at boot time, can be difficult to manage manually, and often require significant changes to code in
order to be used effectively. Most recent Linux OS releases have THP enabled by default.
Linux Huge Page settings
If you need finer control you can manually set huge pages using the following steps:
- Create a mount point for the huge pages:
mkdir /mnt/hugepages
- The huge page file system needs to be mounted when the systems reboots. Add the following to a system boot
configuration file before any services are started:
mount -t hugetlbfs nodev /mnt/hugepages
- Set
vm/nr_hugepages=N in /etc/sysctl.conf where N is the maximum number of pages the
system may allocate.
- Reboot to have the changes take effect.
Note that further information about huge pages may be found in the Linux kernel documentation file
hugetlbpage.txt.
ulimit -s <n>
Sets the stack size to n kbytes, or unlimited to allow the stack size to grow without limit.
ulimit -l <n>
Sets the maximum size of memory that may be locked into physical memory.
powersave -f (on SuSE)
Makes the powersave daemon set the CPUs to the highest supported frequency.
/etc/init.d/cpuspeed stop (on Red Hat)
Disables the cpu frequency scaling program in order to set the CPUs to the highest supported frequency.
LD_LIBRARY_PATH
An environment variable set to include the LLVM, JEMalloc and SmartHeap libraries used during compilation of the
binaries. This environment variable setting is not needed when building the binaries on the system under test.
kernel/randomize_va_space
This option can be used to select the type of process address space randomization that is used in the system, for
architectures that support this feature.
- 0 - Turn the process address space randomization off. This is the default for architectures that do not support
this feature anyway, and kernels that are booted with the "
norandmaps" parameter.
- 1 - Make the addresses of mmap base, stack and VDSO page randomized. This, among other things, implies that
shared libraries will be loaded to random addresses. Also for PIE-linked binaries, the location of code start is
randomized. This is the default if the
CONFIG_COMPAT_BRK option is enabled.
- 2 - Additionally enable heap randomization. This is the default if
CONFIG_COMPAT_BRK is
disabled.
MALLOC_CONF
An environment variable set to tune the jemalloc allocation strategy during the execution of the binaries. This
environment variable setting is not needed when building the binaries on the system under test.
Sw environment from gcc
GNU Compiler Collection Flags
One or more of the following may have been used in the run. If so, it will be listed in the notes sections. Here
is a brief guide to understanding them:
LD_LIBRARY_PATH=<directories> (set via config file preENV)
LD_LIBRARY_PATH controls the search order for libraries. Often, it can be defaulted. Sometimes, it is
explicitly set (as documented in the notes in the submission), in order to ensure that the correct versions of
libraries are picked up.
OMP_STACKSIZE=N (set via config file preENV)
Set the stack size for subordinate threads.
ulimit -s N
ulimit -s unlimited
'ulimit' is a Unix commands, entered prior to the run. It sets the stack size for the main process, either
to N kbytes or to no limit.
For questions about the meanings of these flags, please contact the tester.
For other inquiries, please contact info@spec.org
Copyright 2017-2018 Standard Performance Evaluation Corporation
Tested with SPEC CPU2017 v1.0.5.
Report generated on 2018-11-13 15:14:00 by SPEC CPU2017 flags formatter v5178.
![[benchmark]](https://www.spec.org/auto/cpu2017/images/benchmark.png)