https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65871
Yann Collet changed:
What|Removed |Added
CC||yann.collet.73 at gmail dot com
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: yann.collet.73 at gmail dot com
Target Milestone: ---
As part of our CI test suite,
we compile and run fuzzer tests every day.
The UBSAN test has been failing for some time now.
I suspect
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67435
--- Comment #10 from Yann Collet ---
> there already is an aligned attribute for functions, variables and fields,
Sure, but none of them is related to aligning the start of an hot instruction
loop. Aligning the function instead looks like a
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67435
--- Comment #8 from Yann Collet ---
Thanks for the link.
It's a very good read, and indeed, completely in line with my recent
experience.
Recommended solution seems to be the same : "-falign-loops=32"
The article also mentions that the issue
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67435
--- Comment #6 from Yann Collet ---
The issue seems in fact related to _instruction alignment_.
More precisely, to alignment of some critical loop.
That's basically why adding some code in the file would just "pushes" some
other code into
: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: yann.collet.73 at gmail dot com
Target Milestone: ---
Some weird effect with gcc (tested version : 4.8.4).
I've got a performance oriented code
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67435
--- Comment #5 from Yann Collet ---
Complementary information :
-Winline : does not output anything (is that normal ?)
-fdump-ipa-inline : produce several large files, the interesting one being 1.5
MB long. That's a huge dump to analyze.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67435
--- Comment #4 from Yann Collet ---
> Gcc also tries to limit code growth for the unit also which might be
> something you are seeing.
Yes, that could be the case.
Is there some information available somewhere on such unit-level limit ?
: enhancement
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: yann.collet.73 at gmail dot com
Target Milestone: ---
Accessing unaligned memory positions used to be forbidden on ARM cpus. But
since ARMv6 (quite many years by now
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65709
--- Comment #18 from Yann Collet yann.collet.73 at gmail dot com ---
This issue makes me wonder : how to efficiently access unaligned memory ?
The case in point is ARM cpu.
They don't support SSE/AVX, so they seem unaffected by this specific
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65709
Yann Collet yann.collet.73 at gmail dot com changed:
What|Removed |Added
CC||yann.collet
11 matches
Mail list logo
