> -----Original Message----- > From: Gcc-patches <gcc-patches- > bounces+kyrylo.tkachov=arm....@gcc.gnu.org> On Behalf Of Kyrylo > Tkachov via Gcc-patches > Sent: Friday, November 18, 2022 9:06 AM > To: gcc-patches@gcc.gnu.org > Subject: [PATCH][committed] aarch64: Fix up LDAPR codegen > > Hi all, > > Upon some further inspection I realised I had misunderstood some > intricacies of the extending loads of the RCPC feature. > This patch fixes up the recent GCC support accordingly. In particular: > * The sign-extending forms are a form of LDAPURS* and are actually part of > FEAT_RCPC2 that is enabled with Armv8.4-a rather than the base Armv8.3-a > FEAT_RCPC. The patch introduces a TARGET_RCPC2 macro and gates this > combine pattern accordingly. > * The assembly output for the zero-extending LDAPR instruction should > always use %w formatting for its destination register. >
... And another follow-up once I realised that the sign-extending load, of
course,
needs to have strictly an X-reg as a destination for DImode extensions and a
W-reg
for SImode ones. The zext pattern change was correct
Bootstrapped and tested on aarch64-none-linux.
Pushing to trunk.
Thanks,
Kyrill
gcc/ChangeLog:
* config/aarch64/atomics.md (*aarch64_atomic_load<ALLX:mode>_rcpc_sext):
Use <GPI:w> for destination format.
* config/aarch64/iterators.md (w_sz): Delete.
gcc/testsuite/ChangeLog:
* gcc.target/aarch64/ldapr-sext.c: Adjust expected output.
> The testcase is split into zero-extending and sign-extending parts since they
> require different architecture pragmas.
> It's also straightforward to add the rest of the FEAT_RCPC2 codegen (with
> immediate offset addressing modes) but that can be done as a separate
> patch.
> Apologies for not catching this sooner, but it hasn't been in trunk long, so
> no
> harm done.
>
> Bootstrapped and tested on aarch64-none-linux-gnu.
> Pushing to trunk.
> Thanks,
> Kyrill
>
> gcc/ChangeLog:
>
> * config/aarch64/aarch64.h (TARGET_RCPC2): Define.
> * config/aarch64/atomics.md
> (*aarch64_atomic_load<ALLX:mode>_rcpc_zext):
> Adjust output template.
> (*aarch64_atomic_load<ALLX:mode>_rcpc_sex): Guard on
> TARGET_RCPC2.
> Adjust output template.
> * config/aarch64/iterators.md (w_sz): New mode attr.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/aarch64/ldapr-ext.c: Rename to...
> * gcc.target/aarch64/ldapr-zext.c: ... This. Fix expected assembly.
> * gcc.target/aarch64/ldapr-sext.c: New test.
ldapur-w.patch
Description: ldapur-w.patch
