Support for data-parallelism for find algorithms

[srinivasyadav18]

Contributes to fixing #2333

This implements vectorization support for find, find_end, find_first_of, find_if, and find_if_not

Proposed Changes

• Adapts new CPOs for find_first_of and find_end.
• Adapts all find related algorithms to datapar.
• Splits find unit test into header and source.
• Adapt unit tests for datapar find

[StellarBot]

Performance test report

HPX Performance

Comparison

BENCHMARK	NO-EXECUTOR
Future Overhead - Create Thread Hierarchical - Latch	(=)

Info

Property	Before	After
HPX Commit	96a2e4b	93e5dcb
HPX Datetime	2021-11-11T08:14:57+00:00	2021-11-30T10:50:12+00:00
Envfile
Hostname	nid00006	nid01137
Clustername	daint	daint
Compiler	/apps/daint/SSL/HPX/packages/llvm-11.0.0/bin/clang++ 11.0.0	/apps/daint/SSL/HPX/packages/llvm-11.0.0/bin/clang++ 11.0.0
Datetime	2021-11-11T09:28:13.071121+01:00	2021-11-30T12:08:59.237553+01:00

Comparison

BENCHMARK	FORK_JOIN_EXECUTOR_DEFAULT_FORK_JOIN_POLICY_ALLOCATOR	PARALLEL_EXECUTOR_DEFAULT_PARALLEL_POLICY_ALLOCATOR	SCHEDULER_EXECUTOR_DEFAULT_SCHEDULER_EXECUTOR_ALLOCATOR
Stream Benchmark - Add	-	-	-
Stream Benchmark - Scale	(=)	(=)	(=)
Stream Benchmark - Triad	-	-	-
Stream Benchmark - Copy	(=)	(=)	(=)

Info

Property	Before	After
HPX Commit	71d8dbe	93e5dcb
HPX Datetime	2021-11-10T19:14:21+00:00	2021-11-30T10:50:12+00:00
Envfile
Hostname	nid00120	nid01137
Clustername	daint	daint
Compiler	/apps/daint/SSL/HPX/packages/llvm-11.0.0/bin/clang++ 11.0.0	/apps/daint/SSL/HPX/packages/llvm-11.0.0/bin/clang++ 11.0.0
Datetime	2021-11-10T20:28:18.266961+01:00	2021-11-30T12:09:14.873918+01:00

Explanation of Symbols

Symbol	MEANING
=	No performance change (confidence interval within ±1%)
(=)	Probably no performance change (confidence interval within ±2%)
(+)/(-)	Very small performance improvement/degradation (≤1%)
+/-	Small performance improvement/degradation (≤5%)
++/--	Large performance improvement/degradation (≤10%)
+++/---	Very large performance improvement/degradation (>10%)
?	Probably no change, but quite large uncertainty (confidence interval with ±5%)
??	Unclear result, very large uncertainty (±10%)
???	Something unexpected…

[hkaiser]

Please use HPX_INVOKE() instead of hpx::util::invoke() in implementation files (not tests, etc.)

[srinivasyadav18]

@hkaiser Thanks for the review :), I will make the required changes soon.

[hkaiser]

This is superseded by STEllAR-GROUP/hpx-local#21