Implement a CPU backend using POCL

[vchuravy]

TODO:

• POCL standalone build to remove dependency on OpenCL_jll
• LLVM 20 fixes pocl/pocl#1784 for support of exception handling

[github-actions]

Benchmark Results

	main	0dcdc8b...	main/0dcdc8b2f1e506...
saxpy/default/Float16/1024	0.0568 ± 0.026 ms	0.0527 ± 0.026 ms	1.08
saxpy/default/Float16/1048576	0.893 ± 0.025 ms	0.89 ± 0.025 ms	1
saxpy/default/Float16/16384	0.0675 ± 0.028 ms	0.0616 ± 0.026 ms	1.09
saxpy/default/Float16/2048	0.0599 ± 0.023 ms	0.0504 ± 0.023 ms	1.19
saxpy/default/Float16/256	0.0635 ± 0.027 ms	0.0473 ± 0.027 ms	1.34
saxpy/default/Float16/262144	0.272 ± 0.026 ms	0.268 ± 0.026 ms	1.01
saxpy/default/Float16/32768	0.0776 ± 0.028 ms	0.075 ± 0.027 ms	1.03
saxpy/default/Float16/4096	0.0647 ± 0.025 ms	0.0558 ± 0.025 ms	1.16
saxpy/default/Float16/512	0.0604 ± 0.026 ms	0.047 ± 0.027 ms	1.28
saxpy/default/Float16/64	0.064 ± 0.027 ms	0.0571 ± 0.028 ms	1.12
saxpy/default/Float16/65536	0.112 ± 0.028 ms	0.102 ± 0.026 ms	1.1
saxpy/default/Float32/1024	0.0535 ± 0.026 ms	0.0522 ± 0.026 ms	1.03
saxpy/default/Float32/1048576	0.478 ± 0.026 ms	0.47 ± 0.057 ms	1.02
saxpy/default/Float32/16384	0.0588 ± 0.027 ms	0.0558 ± 0.025 ms	1.05
saxpy/default/Float32/2048	0.0546 ± 0.024 ms	0.0474 ± 0.024 ms	1.15
saxpy/default/Float32/256	0.0616 ± 0.026 ms	0.052 ± 0.028 ms	1.18
saxpy/default/Float32/262144	0.168 ± 0.035 ms	0.157 ± 0.035 ms	1.07
saxpy/default/Float32/32768	0.0643 ± 0.027 ms	0.0614 ± 0.025 ms	1.05
saxpy/default/Float32/4096	0.0639 ± 0.025 ms	0.0516 ± 0.025 ms	1.24
saxpy/default/Float32/512	0.06 ± 0.026 ms	0.0484 ± 0.028 ms	1.24
saxpy/default/Float32/64	0.0631 ± 0.026 ms	0.048 ± 0.028 ms	1.31
saxpy/default/Float32/65536	0.0838 ± 0.029 ms	0.0753 ± 0.029 ms	1.11
saxpy/default/Float64/1024	0.0579 ± 0.026 ms	0.0465 ± 0.026 ms	1.24
saxpy/default/Float64/1048576	0.512 ± 0.051 ms	0.502 ± 0.045 ms	1.02
saxpy/default/Float64/16384	0.0604 ± 0.027 ms	0.0569 ± 0.026 ms	1.06
saxpy/default/Float64/2048	0.0523 ± 0.024 ms	0.0475 ± 0.023 ms	1.1
saxpy/default/Float64/256	0.0613 ± 0.026 ms	0.0553 ± 0.028 ms	1.11
saxpy/default/Float64/262144	0.176 ± 0.029 ms	0.174 ± 0.03 ms	1.01
saxpy/default/Float64/32768	0.0666 ± 0.027 ms	0.0647 ± 0.026 ms	1.03
saxpy/default/Float64/4096	0.0627 ± 0.025 ms	0.0506 ± 0.025 ms	1.24
saxpy/default/Float64/512	0.0606 ± 0.026 ms	0.0473 ± 0.028 ms	1.28
saxpy/default/Float64/64	0.0607 ± 0.027 ms	0.0469 ± 0.028 ms	1.3
saxpy/default/Float64/65536	0.0917 ± 0.027 ms	0.0835 ± 0.027 ms	1.1
saxpy/static workgroup=(1024,)/Float16/1024	0.0535 ± 0.026 ms	0.0459 ± 0.026 ms	1.17
saxpy/static workgroup=(1024,)/Float16/1048576	0.901 ± 0.028 ms	0.901 ± 0.031 ms	1
saxpy/static workgroup=(1024,)/Float16/16384	0.0613 ± 0.026 ms	0.0596 ± 0.024 ms	1.03
saxpy/static workgroup=(1024,)/Float16/2048	0.0575 ± 0.024 ms	0.0501 ± 0.024 ms	1.15
saxpy/static workgroup=(1024,)/Float16/256	0.0631 ± 0.026 ms	0.049 ± 0.027 ms	1.29
saxpy/static workgroup=(1024,)/Float16/262144	0.272 ± 0.028 ms	0.267 ± 0.027 ms	1.02
saxpy/static workgroup=(1024,)/Float16/32768	0.0774 ± 0.026 ms	0.0721 ± 0.024 ms	1.07
saxpy/static workgroup=(1024,)/Float16/4096	0.0631 ± 0.027 ms	0.052 ± 0.027 ms	1.21
saxpy/static workgroup=(1024,)/Float16/512	0.057 ± 0.026 ms	0.0442 ± 0.026 ms	1.29
saxpy/static workgroup=(1024,)/Float16/64	0.0598 ± 0.026 ms	0.0494 ± 0.027 ms	1.21
saxpy/static workgroup=(1024,)/Float16/65536	0.107 ± 0.026 ms	0.101 ± 0.025 ms	1.07
saxpy/static workgroup=(1024,)/Float32/1024	0.0556 ± 0.026 ms	0.0545 ± 0.026 ms	1.02
saxpy/static workgroup=(1024,)/Float32/1048576	0.465 ± 0.028 ms	0.459 ± 0.048 ms	1.01
saxpy/static workgroup=(1024,)/Float32/16384	0.0551 ± 0.026 ms	0.0526 ± 0.024 ms	1.05
saxpy/static workgroup=(1024,)/Float32/2048	0.0511 ± 0.023 ms	0.0458 ± 0.023 ms	1.12
saxpy/static workgroup=(1024,)/Float32/256	0.0629 ± 0.025 ms	0.0506 ± 0.026 ms	1.24
saxpy/static workgroup=(1024,)/Float32/262144	0.161 ± 0.035 ms	0.151 ± 0.034 ms	1.07
saxpy/static workgroup=(1024,)/Float32/32768	0.0605 ± 0.027 ms	0.058 ± 0.025 ms	1.04
saxpy/static workgroup=(1024,)/Float32/4096	0.0598 ± 0.026 ms	0.0475 ± 0.026 ms	1.26
saxpy/static workgroup=(1024,)/Float32/512	0.0612 ± 0.025 ms	0.0467 ± 0.026 ms	1.31
saxpy/static workgroup=(1024,)/Float32/64	0.0617 ± 0.025 ms	0.0508 ± 0.026 ms	1.22
saxpy/static workgroup=(1024,)/Float32/65536	0.079 ± 0.029 ms	0.0714 ± 0.028 ms	1.11
saxpy/static workgroup=(1024,)/Float64/1024	0.0581 ± 0.026 ms	0.0465 ± 0.026 ms	1.25
saxpy/static workgroup=(1024,)/Float64/1048576	0.504 ± 0.041 ms	0.497 ± 0.041 ms	1.02
saxpy/static workgroup=(1024,)/Float64/16384	0.0566 ± 0.026 ms	0.0545 ± 0.025 ms	1.04
saxpy/static workgroup=(1024,)/Float64/2048	0.0525 ± 0.024 ms	0.0464 ± 0.024 ms	1.13
saxpy/static workgroup=(1024,)/Float64/256	0.0594 ± 0.025 ms	0.0492 ± 0.026 ms	1.21
saxpy/static workgroup=(1024,)/Float64/262144	0.173 ± 0.03 ms	0.169 ± 0.031 ms	1.02
saxpy/static workgroup=(1024,)/Float64/32768	0.0652 ± 0.026 ms	0.062 ± 0.025 ms	1.05
saxpy/static workgroup=(1024,)/Float64/4096	0.0596 ± 0.026 ms	0.0485 ± 0.026 ms	1.23
saxpy/static workgroup=(1024,)/Float64/512	0.0587 ± 0.026 ms	0.0453 ± 0.026 ms	1.3
saxpy/static workgroup=(1024,)/Float64/64	0.06 ± 0.025 ms	0.0445 ± 0.026 ms	1.35
saxpy/static workgroup=(1024,)/Float64/65536	0.0901 ± 0.028 ms	0.08 ± 0.028 ms	1.13
time_to_load	1.12 ± 0.012 s	1.12 ± 0.01 s	0.998

Benchmark Plots

A plot of the benchmark results have been uploaded as an artifact to the workflow run for this PR.
Go to "Actions"->"Benchmark a pull request"->[the most recent run]->"Artifacts" (at the bottom).

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 879 lines in your changes missing coverage. Please review.

Project coverage is 0.00%. Comparing base (da32c2b) to head (0dcdc8b).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
src/pocl/nanoOpenCL.jl	0.00%	517 Missing ⚠️
src/pocl/device/array.jl	0.00%	101 Missing ⚠️
src/pocl/backend.jl	0.00%	93 Missing ⚠️
src/pocl/compiler/execution.jl	0.00%	43 Missing ⚠️
src/pocl/compiler/compilation.jl	0.00%	32 Missing ⚠️
src/pocl/device/quirks.jl	0.00%	24 Missing ⚠️
src/pocl/compiler/reflection.jl	0.00%	23 Missing ⚠️
src/pocl/pocl.jl	0.00%	20 Missing ⚠️
src/pocl/device/runtime.jl	0.00%	13 Missing ⚠️
src/macros.jl	0.00%	6 Missing ⚠️
... and 2 more

Additional details and impacted files

@@          Coverage Diff           @@
##            main    #556    +/-   ##
======================================
  Coverage   0.00%   0.00%            
======================================
  Files         12      21     +9     
  Lines        796    1584   +788     
======================================
- Misses       796    1584   +788     

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[vchuravy]

• Implement a CPU backend using POCL #556 : 2 dependent PRs (#558 , #562 ) 👈 (View in Graphite)
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

[vchuravy]

@maleadt this will be fun.

[vchuravy]

Merge activity

• Feb 17, 7:42 AM EST: A user started a stack merge that includes this pull request via Graphite.
• Feb 17, 7:43 AM EST: A user merged this pull request with Graphite.

[vchuravy]

Welp... This got merged by graphite to soon.

Now we have a release-0.9 branch and main is now for 0.10