On 05/22/20 12:12, Ard Biesheuvel wrote: > GCC 10 enabled a feature by default that was introduced in GCC 9, > which results in atomic operations to be emitted as function calls > to intrinsics provided by a runtime library. > > Atomics are hardly used in EDK2, which runs on a single CPU anyway, > and any benefit that would result from reusing library code that > implements these operations is defeated by the fact that every EDK2 > module will need to have its own copy anyway. > > So let's disable this feature on GCC versions that support the > pragma to do so (GCC 10.2 and up) > > Link: https://bugzilla.tianocore.org/show_bug.cgi?id=2723 > Signed-off-by: Ard Biesheuvel <ard.biesheu...@arm.com> > --- > The GCC support for this pragma has already been pulled into the 10.2 > release branch. I think we should consider adding this to the stable > tag, so that the issue can easily be resolved by upgrading the compiler. > Whether we add the intrinsics too is a separate matter, but we can > revisit that later. > > MdePkg/Include/AArch64/ProcessorBind.h | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/MdePkg/Include/AArch64/ProcessorBind.h > b/MdePkg/Include/AArch64/ProcessorBind.h > index 896bf273ac7a..a3ca8f09e51c 100644 > --- a/MdePkg/Include/AArch64/ProcessorBind.h > +++ b/MdePkg/Include/AArch64/ProcessorBind.h > @@ -24,6 +24,17 @@ > #pragma pack() > #endif > > +#if defined(__GNUC__) && !defined(__clang__) > + > +// > +// Disable GCC outline atomics > +// Link: https://bugzilla.tianocore.org/show_bug.cgi?id=2723 > +// > +#if __GNUC__ > 10 || (__GNUC__ == 10 && __GNUC_MINOR__ >= 2) > +#pragma GCC target "no-outline-atomics" > +#endif > +#endif > + > #if defined(_MSC_EXTENSIONS) > > // >
Reviewed-by: Laszlo Ersek <ler...@redhat.com> But I think it should be merged later, after GCC 10.2 is out. (Obviously I don't "insist" that we follow this approach, I'm just OK with it.) Thanks Laszlo -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#60169): https://edk2.groups.io/g/devel/message/60169 Mute This Topic: https://groups.io/mt/74396053/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
