alpaka-group / llama

A Low-Level Abstraction of Memory Access

https://llama-doc.rtfd.io/

Mozilla Public License 2.0

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Improve SoA with static array extents #653

Closed bernhardmgruber closed 1 year ago

bernhardmgruber commented 1 year ago

This PR improves the SoA by precomputing a compile-time only subarray offset table when the array extents are fully static.

This PR also contains an extension of the vectoradd benchmarks:

Mix data types in record dimension, so padding and alignment can have an effect
Make problem size an odd number
Plot results
Test all LLAMA versions in a single run
Test a few variations of the SoA layout
Simplify alpaka use

codecov[bot] commented 1 year ago

Codecov Report

Merging #653 (1ee97e4) into develop (4271b5a) will increase coverage by 0.00%. The diff coverage is 100.00%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #653 +/- ## ======================================== Coverage 98.75% 98.75% ======================================== Files 74 74 Lines 6818 6828 +10 ======================================== + Hits 6733 6743 +10 Misses 85 85 ```

bernhardmgruber commented 1 year ago

Runtime difference is marginal:

layout	runtime
"SoA SB aligned"	0.113894
"SoA SB aligned CT size"	0.113254

compile time:

runtime:

bernhardmgruber commented 1 year ago

layout	runtime
"SoA SB aligned"	0.160085
"SoA SB aligned CT size"	0.160387

Here, the CT variant is actually a bit slower. But the assembly is better (less instructions).