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

[Christophe LYON <christophe.lyon@foss.st.com>]

ping?


On 16/08/2021 13:51, Christophe LYON via Gcc-patches wrote:
> ping?
>
> On 11/08/2021 16:06, Christophe Lyon wrote:
>> ping?
>> https://gcc.gnu.org/pipermail/gcc-patches/2021-July/575310.html 
>> <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 <mailto: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 <mailto: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
>>     <mailto: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.
>>     >
>>     >
>>