Re: [PATCH] arm: Fix multilib mapping for CDE extensions [PR100856]

[Christophe Lyon <christophe.lyon.oss@gmail.com>]

ping?
https://gcc.gnu.org/pipermail/gcc-patches/2021-July/575310.html


On Wed, Aug 4, 2021 at 11:13 AM Christophe Lyon via Gcc-patches <
gcc-patches@gcc.gnu.org> wrote:

> ping?
>
> On Thu, 15 Jul 2021 at 15:07, Christophe LYON via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
> >
> > This is a followup to Srinath's recent patch: the newly added test is
> > failing e.g. on arm-linux-gnueabihf without R/M profile multilibs.
> >
> > It is also failing on arm-eabi with R/M profile multilibs if the
> > execution engine does not support v8.1-M instructions.
> >
> > The patch avoids this by adding check_effective_target_FUNC_multilib
> > in target-supports.exp which effectively checks whether the target
> > supports linking and execution, like what is already done for other
> > ARM effective targets.  pr100856.c is updated to use it instead of
> > arm_v8_1m_main_cde_mve_ok (which makes the testcase a bit of a
> > duplicate with check_effective_target_FUNC_multilib).
> >
> > In addition, I noticed that requiring MVE does not seem necessary and
> > this enables the test to pass even when targeting a CPU without MVE:
> > since the test does not involve actual CDE instructions, it can pass
> > on other architecture versions.  For instance, when requiring MVE, we
> > have to use cortex-m55 under QEMU for the test to pass because the
> > memset() that comes from v8.1-m.main+mve multilib uses LOB
> > instructions (DLS) (memset is used during startup).  Keeping
> > arm_v8_1m_main_cde_mve_ok would mean we would enable the test provided
> > we have the right multilibs, causing a runtime error if the simulator
> > does not support LOB instructions (e.g. when targeting cortex-m7).
> >
> > I do not update sourcebuild.texi since the CDE effective targets are
> > already collectively documented.
> >
> > Finally, the patch fixes two typos in comments.
> >
> > 2021-07-15  Christophe Lyon  <christophe.lyon@foss.st.com>
> >
> >          PR target/100856
> >          gcc/
> >          * config/arm/arm.opt: Fix typo.
> >          * config/arm/t-rmprofile: Fix typo.
> >
> >          gcc/testsuite/
> >          * gcc.target/arm/acle/pr100856.c: Use arm_v8m_main_cde_multilib
> >          and arm_v8m_main_cde.
> >          * lib/target-supports.exp: Add
> > check_effective_target_FUNC_multilib for ARM CDE.
> >
> >
>