compiler-explorer
[REQUEST]: Support LLVM-MCA for armv8-a clang
Is your feature request related to a problem? Please describe
LLVM-MCA is supported for X86-64 clang compilers, but not for armv8-a clang:
"The current language or compiler does not support this tool"
Describe the solution you'd like
LLVM-MCA is supported for armv8-a. Could support be added for armv8-a?
Describe alternatives you've considered
n/a
Additional context
Not applicable
Involves removing the mention of arm and aarch here https://github.com/compiler-explorer/compiler-explorer/blob/be5a9802470986942c572dd14f2a47ab14002699/etc/config/c%2B%2B.amazon.properties#L4512
(5 years ago it did not support arm and we intentionally disabled it for that reason)
Makes sense. Not sure about arm though, that might not be very well supported, but agree that we want to remove aarch from that list.
@partouf: are you happy if I create a merge request for this? The fix looks very simple. Testing would be more challenging for me, but installing compiler explorer locally and giving it a try looks very doable.
@partouf: are you happy if I create a merge request for this? The fix looks very simple. Testing would be more challenging for me, but installing compiler explorer locally and giving it a try looks very doable.
please do, no need for testing really, we can do that more quickly
Is this now supported on compiler explorer? I might misunderstood the initial request or the PR, but when I look at the example here: https://godbolt.org/z/f6d9h1Gvz I do think I can use llvm-mca.
Doesn't look like it, not sure what's going on. Thanks for the ping, will investigate later
Congratulations to being on c++cast and thanks for all the nice discussions, @partouf . Do you have an idea what the issue with mca for arm is?
this should be fixed now and it is live, be aware that you do need to pass --march and --mcpu to llvm-mca before it understands what's going on