Aligned single blob SoA

[bernhardmgruber]

This PR adds a new flag to the single blob SoA mapping to allow aligning the sub arrays.

• unit tests
• performance test

[codecov]

Codecov Report

Merging #415 (2e65925) into develop (e38df38) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop     #415      +/-   ##
===========================================
+ Coverage    99.26%   99.29%   +0.02%     
===========================================
  Files           63       63              
  Lines         5609     5782     +173     
===========================================
+ Hits          5568     5741     +173     
  Misses          41       41              

[bernhardmgruber]

Running the n-body example with changing the Y field in Pos and Vel to a double, so alignment actually matters:

Packed Single Blob SoA
Blob size: 65536
update 0.19956 s	move 5.35e-06 s
update 0.199539 s	move 5.369e-06 s
update 0.199493 s	move 4.84e-06 s
update 0.199491 s	move 4.81e-06 s
update 0.199157 s	move 7.48e-06 s

Aligned Single Blob SoA
Blob size: 589824
update 0.193708 s	move 6.5e-06 s
update 0.193934 s	move 6.38e-06 s
update 0.19397 s	move 6.63e-06 s
update 0.193862 s	move 5.46e-06 s
update 0.193874 s	move 7.38e-06 s

While performance is great, the blob size is worrying.

[bernhardmgruber]

Ok, looks good now:

Packed Single Blob SoA
Blob size: 590292
update 0.197272 s	move 4.66e-06 s
update 0.198951 s	move 4.73e-06 s
update 0.197934 s	move 4.69e-06 s
update 0.197823 s	move 4.67e-06 s
update 0.197902 s	move 4.65e-06 s

Aligned Single Blob SoA
Blob size: 590296
update 0.197533 s	move 4.62e-06 s
update 0.197976 s	move 4.54e-06 s
update 0.196911 s	move 4.59e-06 s
update 0.197672 s	move 1.45e-05 s
update 0.199223 s	move 5.39e-06 s