[fedora-arm] GCC status update

[Henrik Nordström]

tor 2011-11-17 klockan 02:55 -0500 skrev Jon Masters:

> * gcc - making sure the bitfields patches are in place for v5

Actually it's not quite in place for v7 even. The gcc in v7 still
generates bad code on volatile bitfield accesses.

And v5 probably needs even more changes in that area if I understood
alignment requirements for v5 correctly.

See separate discussion on 9 Nov last week regardign GCC PR #50521.

It would be great if we could get help from some gcc developers in
analysing the needed changes. The suggested patch which seems to fix
known code generation is not yet in gcc trunk and is why we have not
included it in the armv7hl gcc package even if it's been discussed a
number of times.

The volatile bitfields issues can be triggered on x86 as well by using
the -fstrict-volatile-bitfields flag. This flag is default on on ARM by
ABI requirement, but off everywhere else and is why the issue hits only
arm.

alignment requirements are platform dependent however.

Regards
Henrik