BFieldCache Change the code so as to emit more clang like assembly for gcc

BFieldCache Change the code so as to emit more clang like assembly for gcc

see [https://godbolt.org/z/zK145fPbe]

ping @amete , this seems to improve things a bit.

But is the reason I asked if we had something with "micro-arch" for vtune.

This is usually called every time the propagators needs to access the magnetic field and is hard to accurately see if was an issue or not.

callgrind shows less branches and less mis-prediction (but callgrind emulates an old processor here). clang assumes the branch will be hard to predict and emit assembly for that assumption, gcc not ...

In some sense for this (no just this bit but the full chain) would be good to get some info on if there is something to improve ...

Build area was cleaned as per request posted in the DB. The full software build will be performed

This merge request affects 1 package:

• MagneticField/MagFieldElements

This merge request affects 1 file:

• MagneticField/MagFieldElements/MagFieldElements/BFieldCache.icc

added Magnets master review-pending-level-1 labels

CI Result SUCCESS (hash c157faab)

	Athena	AthSimulation
externals
cmake
make
tests

Full details available on this CI monitor view. Check the JIRA CI status board for known problems
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 63021]

changed the description

Approved
Albert (L1)

added review-approved label and removed review-pending-level-1 label

added review-approved-tier0 label

added review-approved-point1 label

merged

mentioned in commit 555fe9ef

added sweep:ignore label