llvm-capstone/pstl
Mark de Wever cbaa3597aa Reland "[CMake] Bumps minimum version to 3.20.0.
This reverts commit d763c6e5e2.

Adds the patch by @hans from
https://github.com/llvm/llvm-project/issues/62719
This patch fixes the Windows build.

d763c6e5e2 reverted the reviews

D144509 [CMake] Bumps minimum version to 3.20.0.

This partly undoes D137724.

This change has been discussed on discourse
https://discourse.llvm.org/t/rfc-upgrading-llvms-minimum-required-cmake-version/66193

Note this does not remove work-arounds for older CMake versions, that
will be done in followup patches.

D150532 [OpenMP] Compile assembly files as ASM, not C

Since CMake 3.20, CMake explicitly passes "-x c" (or equivalent)
when compiling a file which has been set as having the language
C. This behaviour change only takes place if "cmake_minimum_required"
is set to 3.20 or newer, or if the policy CMP0119 is set to new.

Attempting to compile assembly files with "-x c" fails, however
this is workarounded in many cases, as OpenMP overrides this with
"-x assembler-with-cpp", however this is only added for non-Windows
targets.

Thus, after increasing cmake_minimum_required to 3.20, this breaks
compiling the GNU assembly for Windows targets; the GNU assembly is
used for ARM and AArch64 Windows targets when building with Clang.
This patch unbreaks that.

D150688 [cmake] Set CMP0091 to fix Windows builds after the cmake_minimum_required bump

The build uses other mechanism to select the runtime.

Fixes #62719

Reviewed By: #libc, Mordante

Differential Revision: https://reviews.llvm.org/D151344
2023-05-27 12:51:21 +02:00
..
cmake
docs Bump the trunk major version to 17 2023-01-24 22:57:27 -08:00
include [libc++][PSTL][NFC] Fix the naming in the SIMD backend 2023-05-04 09:14:56 -07:00
test [NFC][Py Reformat] Reformat python files in the rest of the dirs 2023-05-25 11:17:05 +02:00
.clang-format
CMakeLists.txt Reland "[CMake] Bumps minimum version to 3.20.0. 2023-05-27 12:51:21 +02:00
CREDITS.txt [pstl] Initial implementation of OpenMP backend, on behalf of Christopher Nelson nadiasvertex@gmail.com 2021-10-15 15:36:07 +03:00
LICENSE.TXT
README.md

Parallel STL

Parallel STL is an implementation of the C++ standard library algorithms with support for execution policies, as specified in ISO/IEC 14882:2017 standard, commonly called C++17. The implementation also supports the unsequenced execution policy specified in Parallelism TS version 2 and proposed for the next version of the C++ standard in the C++ working group paper P1001. Parallel STL offers efficient support for both parallel and vectorized execution of algorithms. For sequential execution, it relies on an available implementation of the C++ standard library.

Prerequisites

To use Parallel STL, you must have the following software installed:

  • C++ compiler with:
    • Support for C++11
    • Support for OpenMP* 4.0 SIMD constructs
  • Threading Building Blocks (TBB) which is available for download at https://github.com/01org/tbb/

Known issues and limitations

  • unseq and par_unseq policies only have effect with compilers that support #pragma omp simd or #pragma simd.
  • Parallel and vector execution is only supported for the algorithms if random access iterators are provided, while for other iterator types the execution will remain serial.
  • The following algorithms do not allow efficient SIMD execution: includes, inplace_merge, merge, nth_element, partial_sort, partial_sort_copy, set_difference, set_intersection, set_symmetric_difference, set_union, sort, stable_partition, stable_sort, unique.
  • The initial value type for exclusive_scan, inclusive_scan, transform_exclusive_scan, transform_inclusive_scan shall be DefaultConstructible. A default constructed-instance of the initial value type shall be the identity element for the specified binary operation.
  • For max_element, min_element, minmax_element, partial_sort, partial_sort_copy, sort, stable_sort the dereferenced value type of the provided iterators shall be DefaultConstructible.
  • For remove, remove_if, unique the dereferenced value type of the provided iterators shall be MoveConstructible.
  • The following algorithms require additional O(n) memory space for parallel execution: copy_if, inplace_merge, partial_sort, partial_sort_copy, partition_copy, remove, remove_if, rotate, sort, stable_sort, unique, unique_copy.