hanchenye-llvm-project/openmp/runtime/README.txt

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README for Intel(R) OpenMP* Runtime Library
===========================================
How to Build Documentation
==========================
The main documentation is in Doxygen* format, and this distribution
should come with pre-built PDF documentation in doc/Reference.pdf.
However, an HTML version can be built by executing:
% doxygen doc/doxygen/config
in this directory.
That will produce HTML documentation in the doc/doxygen/generated
directory, which can be accessed by pointing a web browser at the
index.html file there.
If you don't have Doxygen installed, you can download it from
www.doxygen.org.
How to Build the Intel(R) OpenMP* Runtime Library
=================================================
The Makefile at the top-level will attempt to detect what it needs to
build the Intel(R) OpenMP* Runtime Library. To see the default settings,
type:
make info
You can change the Makefile's behavior with the following options:
omp_root: The path to the top-level directory containing the top-level
Makefile. By default, this will take on the value of the
current working directory.
omp_os: Operating system. By default, the build will attempt to
I apologise in advance for the size of this check-in. At Intel we do understand that this is not friendly, and are working to change our internal code-development to make it easier to make development features available more frequently and in finer (more functional) chunks. Unfortunately we haven't got that in place yet, and unpicking this into multiple separate check-ins would be non-trivial, so please bear with me on this one. We should be better in the future. Apologies over, what do we have here? GGC 4.9 compatibility -------------------- * We have implemented the new entrypoints used by code compiled by GCC 4.9 to implement the same functionality in gcc 4.8. Therefore code compiled with gcc 4.9 that used to work will continue to do so. However, there are some other new entrypoints (associated with task cancellation) which are not implemented. Therefore user code compiled by gcc 4.9 that uses these new features will not link against the LLVM runtime. (It remains unclear how to handle those entrypoints, since the GCC interface has potentially unpleasant performance implications for join barriers even when cancellation is not used) --- new parallel entry points --- new entry points that aren't OpenMP 4.0 related These are implemented fully :- GOMP_parallel_loop_dynamic() GOMP_parallel_loop_guided() GOMP_parallel_loop_runtime() GOMP_parallel_loop_static() GOMP_parallel_sections() GOMP_parallel() --- cancellation entry points --- Currently, these only give a runtime error if OMP_CANCELLATION is true because our plain barriers don't check for cancellation while waiting GOMP_barrier_cancel() GOMP_cancel() GOMP_cancellation_point() GOMP_loop_end_cancel() GOMP_sections_end_cancel() --- taskgroup entry points --- These are implemented fully. GOMP_taskgroup_start() GOMP_taskgroup_end() --- target entry points --- These are empty (as they are in libgomp) GOMP_target() GOMP_target_data() GOMP_target_end_data() GOMP_target_update() GOMP_teams() Improvements in Barriers and Fork/Join -------------------------------------- * Barrier and fork/join code is now in its own file (which makes it easier to understand and modify). * Wait/release code is now templated and in its own file; suspend/resume code is also templated * There's a new, hierarchical, barrier, which exploits the cache-hierarchy of the Intel(r) Xeon Phi(tm) coprocessor to improve fork/join and barrier performance. ***BEWARE*** the new source files have *not* been added to the legacy Cmake build system. If you want to use that fixes wil be required. Statistics Collection Code -------------------------- * New code has been added to collect application statistics (if this is enabled at library compile time; by default it is not). The statistics code itself is generally useful, the lightweight timing code uses the X86 rdtsc instruction, so will require changes for other architectures. The intent of this code is not for users to tune their codes but rather 1) For timing code-paths inside the runtime 2) For gathering general properties of OpenMP codes to focus attention on which OpenMP features are most used. Nested Hot Teams ---------------- * The runtime now maintains more state to reduce the overhead of creating and destroying inner parallel teams. This improves the performance of code that repeatedly uses nested parallelism with the same resource allocation. Set the new KMP_HOT_TEAMS_MAX_LEVEL envirable to a depth to enable this (and, of course, OMP_NESTED=true to enable nested parallelism at all). Improved Intel(r) VTune(Tm) Amplifier support --------------------------------------------- * The runtime provides additional information to Vtune via the itt_notify interface to allow it to display better OpenMP specific analyses of load-imbalance. Support for OpenMP Composite Statements --------------------------------------- * Implement new entrypoints required by some of the OpenMP 4.1 composite statements. Improved ifdefs --------------- * More separation of concepts ("Does this platform do X?") from platforms ("Are we compiling for platform Y?"), which should simplify future porting. ScaleMP* contribution --------------------- Stack padding to improve the performance in their environment where cross-node coherency is managed at the page level. Redesign of wait and release code --------------------------------- The code is simplified and performance improved. Bug Fixes --------- *Fixes for Windows multiple processor groups. *Fix Fortran module build on Linux: offload attribute added. *Fix entry names for distribute-parallel-loop construct to be consistent with the compiler codegen. *Fix an inconsistent error message for KMP_PLACE_THREADS environment variable. llvm-svn: 219214
2014-10-08 00:25:50 +08:00
detect this. Currently supports "linux", "freebsd", "macos", and
"windows".
arch: Architecture. By default, the build will attempt to
detect this if not specified by the user. Currently
supported values are
"32" for IA-32 architecture
"32e" for Intel(R) 64 architecture
"mic" for Intel(R) Many Integrated Core Architecture
If "mic" is specified then "icc" will be used as the
compiler, and appropriate k1om binutils will be used. The
necessary packages must be installed on the build machine
for this to be possible (but an Intel(R) Xeon Phi(TM)
coprocessor card is not required to build the library).
compiler: Which compiler to use for the build. Defaults to "icc"
or "icl" depending on the value of omp_os. Also supports
some versions of "gcc"* when omp_os is "linux". The selected
compiler should be installed and in the user's path. The
corresponding Fortran compiler should also be in the path.
See "Supported RTL Build Configurations" below for more
information on compiler versions.
mode: Library mode: default is "release". Also supports "debug".
To use any of the options above, simple add <option_name>=<value>. For
example, if you want to build with gcc instead of icc, type:
make compiler=gcc
There is also an experimental CMake build system. This is *not* yet
supported for production use and resulting binaries have not been checked
for compatibility.
I apologise in advance for the size of this check-in. At Intel we do understand that this is not friendly, and are working to change our internal code-development to make it easier to make development features available more frequently and in finer (more functional) chunks. Unfortunately we haven't got that in place yet, and unpicking this into multiple separate check-ins would be non-trivial, so please bear with me on this one. We should be better in the future. Apologies over, what do we have here? GGC 4.9 compatibility -------------------- * We have implemented the new entrypoints used by code compiled by GCC 4.9 to implement the same functionality in gcc 4.8. Therefore code compiled with gcc 4.9 that used to work will continue to do so. However, there are some other new entrypoints (associated with task cancellation) which are not implemented. Therefore user code compiled by gcc 4.9 that uses these new features will not link against the LLVM runtime. (It remains unclear how to handle those entrypoints, since the GCC interface has potentially unpleasant performance implications for join barriers even when cancellation is not used) --- new parallel entry points --- new entry points that aren't OpenMP 4.0 related These are implemented fully :- GOMP_parallel_loop_dynamic() GOMP_parallel_loop_guided() GOMP_parallel_loop_runtime() GOMP_parallel_loop_static() GOMP_parallel_sections() GOMP_parallel() --- cancellation entry points --- Currently, these only give a runtime error if OMP_CANCELLATION is true because our plain barriers don't check for cancellation while waiting GOMP_barrier_cancel() GOMP_cancel() GOMP_cancellation_point() GOMP_loop_end_cancel() GOMP_sections_end_cancel() --- taskgroup entry points --- These are implemented fully. GOMP_taskgroup_start() GOMP_taskgroup_end() --- target entry points --- These are empty (as they are in libgomp) GOMP_target() GOMP_target_data() GOMP_target_end_data() GOMP_target_update() GOMP_teams() Improvements in Barriers and Fork/Join -------------------------------------- * Barrier and fork/join code is now in its own file (which makes it easier to understand and modify). * Wait/release code is now templated and in its own file; suspend/resume code is also templated * There's a new, hierarchical, barrier, which exploits the cache-hierarchy of the Intel(r) Xeon Phi(tm) coprocessor to improve fork/join and barrier performance. ***BEWARE*** the new source files have *not* been added to the legacy Cmake build system. If you want to use that fixes wil be required. Statistics Collection Code -------------------------- * New code has been added to collect application statistics (if this is enabled at library compile time; by default it is not). The statistics code itself is generally useful, the lightweight timing code uses the X86 rdtsc instruction, so will require changes for other architectures. The intent of this code is not for users to tune their codes but rather 1) For timing code-paths inside the runtime 2) For gathering general properties of OpenMP codes to focus attention on which OpenMP features are most used. Nested Hot Teams ---------------- * The runtime now maintains more state to reduce the overhead of creating and destroying inner parallel teams. This improves the performance of code that repeatedly uses nested parallelism with the same resource allocation. Set the new KMP_HOT_TEAMS_MAX_LEVEL envirable to a depth to enable this (and, of course, OMP_NESTED=true to enable nested parallelism at all). Improved Intel(r) VTune(Tm) Amplifier support --------------------------------------------- * The runtime provides additional information to Vtune via the itt_notify interface to allow it to display better OpenMP specific analyses of load-imbalance. Support for OpenMP Composite Statements --------------------------------------- * Implement new entrypoints required by some of the OpenMP 4.1 composite statements. Improved ifdefs --------------- * More separation of concepts ("Does this platform do X?") from platforms ("Are we compiling for platform Y?"), which should simplify future porting. ScaleMP* contribution --------------------- Stack padding to improve the performance in their environment where cross-node coherency is managed at the page level. Redesign of wait and release code --------------------------------- The code is simplified and performance improved. Bug Fixes --------- *Fixes for Windows multiple processor groups. *Fix Fortran module build on Linux: offload attribute added. *Fix entry names for distribute-parallel-loop construct to be consistent with the compiler codegen. *Fix an inconsistent error message for KMP_PLACE_THREADS environment variable. llvm-svn: 219214
2014-10-08 00:25:50 +08:00
On OS X* machines, it is possible to build universal (or fat) libraries which
include both IA-32 architecture and Intel(R) 64 architecture objects in a
single archive; just build the 32 and 32e libraries separately, then invoke
make again with a special argument as follows:
make compiler=clang build_args=fat
Supported RTL Build Configurations
==================================
Supported Architectures: IA-32 architecture, Intel(R) 64, and
Intel(R) Many Integrated Core Architecture
I apologise in advance for the size of this check-in. At Intel we do understand that this is not friendly, and are working to change our internal code-development to make it easier to make development features available more frequently and in finer (more functional) chunks. Unfortunately we haven't got that in place yet, and unpicking this into multiple separate check-ins would be non-trivial, so please bear with me on this one. We should be better in the future. Apologies over, what do we have here? GGC 4.9 compatibility -------------------- * We have implemented the new entrypoints used by code compiled by GCC 4.9 to implement the same functionality in gcc 4.8. Therefore code compiled with gcc 4.9 that used to work will continue to do so. However, there are some other new entrypoints (associated with task cancellation) which are not implemented. Therefore user code compiled by gcc 4.9 that uses these new features will not link against the LLVM runtime. (It remains unclear how to handle those entrypoints, since the GCC interface has potentially unpleasant performance implications for join barriers even when cancellation is not used) --- new parallel entry points --- new entry points that aren't OpenMP 4.0 related These are implemented fully :- GOMP_parallel_loop_dynamic() GOMP_parallel_loop_guided() GOMP_parallel_loop_runtime() GOMP_parallel_loop_static() GOMP_parallel_sections() GOMP_parallel() --- cancellation entry points --- Currently, these only give a runtime error if OMP_CANCELLATION is true because our plain barriers don't check for cancellation while waiting GOMP_barrier_cancel() GOMP_cancel() GOMP_cancellation_point() GOMP_loop_end_cancel() GOMP_sections_end_cancel() --- taskgroup entry points --- These are implemented fully. GOMP_taskgroup_start() GOMP_taskgroup_end() --- target entry points --- These are empty (as they are in libgomp) GOMP_target() GOMP_target_data() GOMP_target_end_data() GOMP_target_update() GOMP_teams() Improvements in Barriers and Fork/Join -------------------------------------- * Barrier and fork/join code is now in its own file (which makes it easier to understand and modify). * Wait/release code is now templated and in its own file; suspend/resume code is also templated * There's a new, hierarchical, barrier, which exploits the cache-hierarchy of the Intel(r) Xeon Phi(tm) coprocessor to improve fork/join and barrier performance. ***BEWARE*** the new source files have *not* been added to the legacy Cmake build system. If you want to use that fixes wil be required. Statistics Collection Code -------------------------- * New code has been added to collect application statistics (if this is enabled at library compile time; by default it is not). The statistics code itself is generally useful, the lightweight timing code uses the X86 rdtsc instruction, so will require changes for other architectures. The intent of this code is not for users to tune their codes but rather 1) For timing code-paths inside the runtime 2) For gathering general properties of OpenMP codes to focus attention on which OpenMP features are most used. Nested Hot Teams ---------------- * The runtime now maintains more state to reduce the overhead of creating and destroying inner parallel teams. This improves the performance of code that repeatedly uses nested parallelism with the same resource allocation. Set the new KMP_HOT_TEAMS_MAX_LEVEL envirable to a depth to enable this (and, of course, OMP_NESTED=true to enable nested parallelism at all). Improved Intel(r) VTune(Tm) Amplifier support --------------------------------------------- * The runtime provides additional information to Vtune via the itt_notify interface to allow it to display better OpenMP specific analyses of load-imbalance. Support for OpenMP Composite Statements --------------------------------------- * Implement new entrypoints required by some of the OpenMP 4.1 composite statements. Improved ifdefs --------------- * More separation of concepts ("Does this platform do X?") from platforms ("Are we compiling for platform Y?"), which should simplify future porting. ScaleMP* contribution --------------------- Stack padding to improve the performance in their environment where cross-node coherency is managed at the page level. Redesign of wait and release code --------------------------------- The code is simplified and performance improved. Bug Fixes --------- *Fixes for Windows multiple processor groups. *Fix Fortran module build on Linux: offload attribute added. *Fix entry names for distribute-parallel-loop construct to be consistent with the compiler codegen. *Fix an inconsistent error message for KMP_PLACE_THREADS environment variable. llvm-svn: 219214
2014-10-08 00:25:50 +08:00
----------------------------------------------
| icc/icl | gcc | clang |
--------------|---------------|----------------------------|
| Linux* OS | Yes(1,5) | Yes(2,4) | Yes(4,6,7) |
| FreeBSD* | No | No | Yes(4,6,7,8) |
| OS X* | Yes(1,3,4) | No | Yes(4,6,7) |
| Windows* OS | Yes(1,4) | No | No |
------------------------------------------------------------
(1) On IA-32 architecture and Intel(R) 64, icc/icl versions 12.x are
supported (12.1 is recommended).
I apologise in advance for the size of this check-in. At Intel we do understand that this is not friendly, and are working to change our internal code-development to make it easier to make development features available more frequently and in finer (more functional) chunks. Unfortunately we haven't got that in place yet, and unpicking this into multiple separate check-ins would be non-trivial, so please bear with me on this one. We should be better in the future. Apologies over, what do we have here? GGC 4.9 compatibility -------------------- * We have implemented the new entrypoints used by code compiled by GCC 4.9 to implement the same functionality in gcc 4.8. Therefore code compiled with gcc 4.9 that used to work will continue to do so. However, there are some other new entrypoints (associated with task cancellation) which are not implemented. Therefore user code compiled by gcc 4.9 that uses these new features will not link against the LLVM runtime. (It remains unclear how to handle those entrypoints, since the GCC interface has potentially unpleasant performance implications for join barriers even when cancellation is not used) --- new parallel entry points --- new entry points that aren't OpenMP 4.0 related These are implemented fully :- GOMP_parallel_loop_dynamic() GOMP_parallel_loop_guided() GOMP_parallel_loop_runtime() GOMP_parallel_loop_static() GOMP_parallel_sections() GOMP_parallel() --- cancellation entry points --- Currently, these only give a runtime error if OMP_CANCELLATION is true because our plain barriers don't check for cancellation while waiting GOMP_barrier_cancel() GOMP_cancel() GOMP_cancellation_point() GOMP_loop_end_cancel() GOMP_sections_end_cancel() --- taskgroup entry points --- These are implemented fully. GOMP_taskgroup_start() GOMP_taskgroup_end() --- target entry points --- These are empty (as they are in libgomp) GOMP_target() GOMP_target_data() GOMP_target_end_data() GOMP_target_update() GOMP_teams() Improvements in Barriers and Fork/Join -------------------------------------- * Barrier and fork/join code is now in its own file (which makes it easier to understand and modify). * Wait/release code is now templated and in its own file; suspend/resume code is also templated * There's a new, hierarchical, barrier, which exploits the cache-hierarchy of the Intel(r) Xeon Phi(tm) coprocessor to improve fork/join and barrier performance. ***BEWARE*** the new source files have *not* been added to the legacy Cmake build system. If you want to use that fixes wil be required. Statistics Collection Code -------------------------- * New code has been added to collect application statistics (if this is enabled at library compile time; by default it is not). The statistics code itself is generally useful, the lightweight timing code uses the X86 rdtsc instruction, so will require changes for other architectures. The intent of this code is not for users to tune their codes but rather 1) For timing code-paths inside the runtime 2) For gathering general properties of OpenMP codes to focus attention on which OpenMP features are most used. Nested Hot Teams ---------------- * The runtime now maintains more state to reduce the overhead of creating and destroying inner parallel teams. This improves the performance of code that repeatedly uses nested parallelism with the same resource allocation. Set the new KMP_HOT_TEAMS_MAX_LEVEL envirable to a depth to enable this (and, of course, OMP_NESTED=true to enable nested parallelism at all). Improved Intel(r) VTune(Tm) Amplifier support --------------------------------------------- * The runtime provides additional information to Vtune via the itt_notify interface to allow it to display better OpenMP specific analyses of load-imbalance. Support for OpenMP Composite Statements --------------------------------------- * Implement new entrypoints required by some of the OpenMP 4.1 composite statements. Improved ifdefs --------------- * More separation of concepts ("Does this platform do X?") from platforms ("Are we compiling for platform Y?"), which should simplify future porting. ScaleMP* contribution --------------------- Stack padding to improve the performance in their environment where cross-node coherency is managed at the page level. Redesign of wait and release code --------------------------------- The code is simplified and performance improved. Bug Fixes --------- *Fixes for Windows multiple processor groups. *Fix Fortran module build on Linux: offload attribute added. *Fix entry names for distribute-parallel-loop construct to be consistent with the compiler codegen. *Fix an inconsistent error message for KMP_PLACE_THREADS environment variable. llvm-svn: 219214
2014-10-08 00:25:50 +08:00
(2) GCC* version 4.6.2 is supported.
(3) For icc on OS X*, OS X* version 10.5.8 is supported.
(4) Intel(R) Many Integrated Core Architecture not supported.
(5) On Intel(R) Many Integrated Core Architecture, icc/icl versions 13.0
or later are required.
I apologise in advance for the size of this check-in. At Intel we do understand that this is not friendly, and are working to change our internal code-development to make it easier to make development features available more frequently and in finer (more functional) chunks. Unfortunately we haven't got that in place yet, and unpicking this into multiple separate check-ins would be non-trivial, so please bear with me on this one. We should be better in the future. Apologies over, what do we have here? GGC 4.9 compatibility -------------------- * We have implemented the new entrypoints used by code compiled by GCC 4.9 to implement the same functionality in gcc 4.8. Therefore code compiled with gcc 4.9 that used to work will continue to do so. However, there are some other new entrypoints (associated with task cancellation) which are not implemented. Therefore user code compiled by gcc 4.9 that uses these new features will not link against the LLVM runtime. (It remains unclear how to handle those entrypoints, since the GCC interface has potentially unpleasant performance implications for join barriers even when cancellation is not used) --- new parallel entry points --- new entry points that aren't OpenMP 4.0 related These are implemented fully :- GOMP_parallel_loop_dynamic() GOMP_parallel_loop_guided() GOMP_parallel_loop_runtime() GOMP_parallel_loop_static() GOMP_parallel_sections() GOMP_parallel() --- cancellation entry points --- Currently, these only give a runtime error if OMP_CANCELLATION is true because our plain barriers don't check for cancellation while waiting GOMP_barrier_cancel() GOMP_cancel() GOMP_cancellation_point() GOMP_loop_end_cancel() GOMP_sections_end_cancel() --- taskgroup entry points --- These are implemented fully. GOMP_taskgroup_start() GOMP_taskgroup_end() --- target entry points --- These are empty (as they are in libgomp) GOMP_target() GOMP_target_data() GOMP_target_end_data() GOMP_target_update() GOMP_teams() Improvements in Barriers and Fork/Join -------------------------------------- * Barrier and fork/join code is now in its own file (which makes it easier to understand and modify). * Wait/release code is now templated and in its own file; suspend/resume code is also templated * There's a new, hierarchical, barrier, which exploits the cache-hierarchy of the Intel(r) Xeon Phi(tm) coprocessor to improve fork/join and barrier performance. ***BEWARE*** the new source files have *not* been added to the legacy Cmake build system. If you want to use that fixes wil be required. Statistics Collection Code -------------------------- * New code has been added to collect application statistics (if this is enabled at library compile time; by default it is not). The statistics code itself is generally useful, the lightweight timing code uses the X86 rdtsc instruction, so will require changes for other architectures. The intent of this code is not for users to tune their codes but rather 1) For timing code-paths inside the runtime 2) For gathering general properties of OpenMP codes to focus attention on which OpenMP features are most used. Nested Hot Teams ---------------- * The runtime now maintains more state to reduce the overhead of creating and destroying inner parallel teams. This improves the performance of code that repeatedly uses nested parallelism with the same resource allocation. Set the new KMP_HOT_TEAMS_MAX_LEVEL envirable to a depth to enable this (and, of course, OMP_NESTED=true to enable nested parallelism at all). Improved Intel(r) VTune(Tm) Amplifier support --------------------------------------------- * The runtime provides additional information to Vtune via the itt_notify interface to allow it to display better OpenMP specific analyses of load-imbalance. Support for OpenMP Composite Statements --------------------------------------- * Implement new entrypoints required by some of the OpenMP 4.1 composite statements. Improved ifdefs --------------- * More separation of concepts ("Does this platform do X?") from platforms ("Are we compiling for platform Y?"), which should simplify future porting. ScaleMP* contribution --------------------- Stack padding to improve the performance in their environment where cross-node coherency is managed at the page level. Redesign of wait and release code --------------------------------- The code is simplified and performance improved. Bug Fixes --------- *Fixes for Windows multiple processor groups. *Fix Fortran module build on Linux: offload attribute added. *Fix entry names for distribute-parallel-loop construct to be consistent with the compiler codegen. *Fix an inconsistent error message for KMP_PLACE_THREADS environment variable. llvm-svn: 219214
2014-10-08 00:25:50 +08:00
(6) Clang* version 3.3 is supported.
(7) Clang* currently does not offer a software-implemented 128 bit extended
precision type. Thus, all entry points reliant on this type are removed
from the library and cannot be called in the user program. The following
functions are not available:
__kmpc_atomic_cmplx16_*
__kmpc_atomic_float16_*
__kmpc_atomic_*_fp
I apologise in advance for the size of this check-in. At Intel we do understand that this is not friendly, and are working to change our internal code-development to make it easier to make development features available more frequently and in finer (more functional) chunks. Unfortunately we haven't got that in place yet, and unpicking this into multiple separate check-ins would be non-trivial, so please bear with me on this one. We should be better in the future. Apologies over, what do we have here? GGC 4.9 compatibility -------------------- * We have implemented the new entrypoints used by code compiled by GCC 4.9 to implement the same functionality in gcc 4.8. Therefore code compiled with gcc 4.9 that used to work will continue to do so. However, there are some other new entrypoints (associated with task cancellation) which are not implemented. Therefore user code compiled by gcc 4.9 that uses these new features will not link against the LLVM runtime. (It remains unclear how to handle those entrypoints, since the GCC interface has potentially unpleasant performance implications for join barriers even when cancellation is not used) --- new parallel entry points --- new entry points that aren't OpenMP 4.0 related These are implemented fully :- GOMP_parallel_loop_dynamic() GOMP_parallel_loop_guided() GOMP_parallel_loop_runtime() GOMP_parallel_loop_static() GOMP_parallel_sections() GOMP_parallel() --- cancellation entry points --- Currently, these only give a runtime error if OMP_CANCELLATION is true because our plain barriers don't check for cancellation while waiting GOMP_barrier_cancel() GOMP_cancel() GOMP_cancellation_point() GOMP_loop_end_cancel() GOMP_sections_end_cancel() --- taskgroup entry points --- These are implemented fully. GOMP_taskgroup_start() GOMP_taskgroup_end() --- target entry points --- These are empty (as they are in libgomp) GOMP_target() GOMP_target_data() GOMP_target_end_data() GOMP_target_update() GOMP_teams() Improvements in Barriers and Fork/Join -------------------------------------- * Barrier and fork/join code is now in its own file (which makes it easier to understand and modify). * Wait/release code is now templated and in its own file; suspend/resume code is also templated * There's a new, hierarchical, barrier, which exploits the cache-hierarchy of the Intel(r) Xeon Phi(tm) coprocessor to improve fork/join and barrier performance. ***BEWARE*** the new source files have *not* been added to the legacy Cmake build system. If you want to use that fixes wil be required. Statistics Collection Code -------------------------- * New code has been added to collect application statistics (if this is enabled at library compile time; by default it is not). The statistics code itself is generally useful, the lightweight timing code uses the X86 rdtsc instruction, so will require changes for other architectures. The intent of this code is not for users to tune their codes but rather 1) For timing code-paths inside the runtime 2) For gathering general properties of OpenMP codes to focus attention on which OpenMP features are most used. Nested Hot Teams ---------------- * The runtime now maintains more state to reduce the overhead of creating and destroying inner parallel teams. This improves the performance of code that repeatedly uses nested parallelism with the same resource allocation. Set the new KMP_HOT_TEAMS_MAX_LEVEL envirable to a depth to enable this (and, of course, OMP_NESTED=true to enable nested parallelism at all). Improved Intel(r) VTune(Tm) Amplifier support --------------------------------------------- * The runtime provides additional information to Vtune via the itt_notify interface to allow it to display better OpenMP specific analyses of load-imbalance. Support for OpenMP Composite Statements --------------------------------------- * Implement new entrypoints required by some of the OpenMP 4.1 composite statements. Improved ifdefs --------------- * More separation of concepts ("Does this platform do X?") from platforms ("Are we compiling for platform Y?"), which should simplify future porting. ScaleMP* contribution --------------------- Stack padding to improve the performance in their environment where cross-node coherency is managed at the page level. Redesign of wait and release code --------------------------------- The code is simplified and performance improved. Bug Fixes --------- *Fixes for Windows multiple processor groups. *Fix Fortran module build on Linux: offload attribute added. *Fix entry names for distribute-parallel-loop construct to be consistent with the compiler codegen. *Fix an inconsistent error message for KMP_PLACE_THREADS environment variable. llvm-svn: 219214
2014-10-08 00:25:50 +08:00
(8) Community contribution provided AS IS, not tested by Intel.
Front-end Compilers that work with this RTL
===========================================
The following compilers are known to do compatible code generation for
this RTL: icc/icl, gcc. See the documentation for more detail.
-----------------------------------------------------------------------
Notices
=======
*Other names and brands may be claimed as the property of others.