llvm-project/openmp/www/README.txt

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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
README for the LLVM* 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
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
in the runtime 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.
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
How to Build the LLVM* OpenMP* Runtime Library
==============================================
In-tree build:
$ cd where-you-want-to-live
Check out openmp into llvm/projects
$ cd where-you-want-to-build
$ mkdir build && cd build
$ cmake path/to/llvm -DCMAKE_C_COMPILER=<C compiler> -DCMAKE_CXX_COMPILER=<C++ compiler>
$ make omp
Out-of-tree build:
$ cd where-you-want-to-live
Check out openmp
$ cd where-you-want-to-live/openmp/runtime
$ mkdir build && cd build
$ cmake path/to/openmp -DCMAKE_C_COMPILER=<C compiler> -DCMAKE_CXX_COMPILER=<C++ compiler>
$ make
For details about building, please look at Build_With_CMake.txt
Architectures Supported
=======================
* IA-32 architecture
* Intel(R) 64 architecture
* Intel(R) Many Integrated Core Architecture
* ARM* architecture
* Aarch64 (64-bit ARM) architecture
* IBM(R) Power architecture (big endian)
* IBM(R) Power architecture (little endian)
* MIPS and MIPS64 architectures
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
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).
(2) GCC* version 4.7 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.
Supported Architectures: IBM(R) Power 7 and Power 8
-----------------------------
| gcc | clang |
--------------|------------|--------------|
| Linux* OS | Yes(1,2) | Yes(3,4) |
-------------------------------------------
(1) On Power 7, gcc version 4.8.2 is supported.
(2) On Power 8, gcc version 4.8.2 is supported.
(3) On Power 7, clang version 3.7 is supported.
(4) On Power 8, clang version 3.7 is supported.
Front-end Compilers that work with this RTL
===========================================
The following compilers are known to do compatible code generation for
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
this RTL: clang (from the OpenMP development branch at
http://clang-omp.github.io/ ), Intel compilers, GCC. See the documentation
for more details.
-----------------------------------------------------------------------
Notices
=======
*Other names and brands may be claimed as the property of others.