Re: [Patch, ARM, testsuite] Add -mfloat-abi=hard to arm_neon_ok

[Christophe Lyon <christophe.lyon@linaro.org>]

ping?

On 16 June 2017 at 17:39, Christophe Lyon <christophe.lyon@linaro.org> wrote:
> ping?
>
> On 7 June 2017 at 11:13, Christophe Lyon <christophe.lyon@linaro.org> wrote:
>> Hi,
>>
>>
>> On 2 June 2017 at 16:19, Christophe Lyon <christophe.lyon@linaro.org> wrote:
>>> Hi,
>>>
>>> I have recently updated the dejagnu version I use for
>>> cross-testing arm and aarch64 toolchains to 1.6+. One of the side
>>> effects was mentioned by Jonathan in
>>> https://gcc.gnu.org/ml/gcc-patches/2017-05/msg01267.html. Since I
>>> use multilibs to test many configurations, I noticed several
>>> changes in the results I get.
>>>
>>> In particular, on arm-none-linux-gnueabihf with -march=armv5t,
>>> all the tests that require arm_neon_ok fail to compile because
>>> they now use -march=armv5t -mfpu=neon -mfloat-abi=softfp
>>> -march=armv7-a, which leads to a failure to include
>>> gnu/stubs-soft.h (not present since the target is
>>> 'hf'). Previously, -march=armv5t was appended, making the tests
>>> unsupported because -mfpu=neon conflicts with -march=armv5t. Now,
>>> arm_neon_ok succeeds because it only checks if some preprocessor
>>> defines are present.
>>>
>>> This patch fixes that by including arm_neon.h in arm_neon_ok, such
>>> that it fails for unsupported cases. However, since most of these
>>> tests should pass instead of becoming unsupported, I have added flag
>>> combinations with -mfloat-abi=hard.
>>>
>>> However, this is not sufficient to make the
>>> gcc.target/arm/lto/pr65837* tests pass: they do not require
>>> arm_neon_ok, and when I tried to add it, they still failed
>>> because these lto tests do not support dg-add-options. My
>>> proposal is to add a new
>>> check_effective_target_arm_neon_ok_no_float_abi function which
>>> tries to use neon without trying to change the -mfloat-abi
>>> setting (that is, the same as arm_neon_ok, with only ""
>>> and "-mfpu=neon" in the list of flags) . This makes these two lto
>>> tests unsupported for non-hf targets (again because
>>> gnu/stubs-soft.h is not present).
>>>
>>> To make them pass on "hf" targets:
>>> - I added -mfpu=neon to dg-lto-options in pr65837-attr_0.c,
>>>   because the fpu attributes in arm_neon.h only work if
>>>   -mfpu=neon is enabled
>>> - I removed dg-suppress-ld-options {-mfpu=neon} from pr65837_0.c,
>>>   -mfpu=neon is needed for the test to compile with toolchains
>>>   where the default fpu is not neon (eg vfpv3-d16-fp16)
>>>
>>> On arm-none-linux-gnueabihf --with-cpu=cortex-a9 --with-fpu=vfp
>>> and multilib test flag=-march=armv5t, this patch brings:
>>> - 2 UNRESOLVED -> FAIL (gcc.dg/vect/vect-align-1.c)
>>> - 14 UNRESOLVED -> XPASS (in gcc.dg/vect/)
>>> - 2765 new PASS
>>> - 3639 FAIL -> PASS
>>> - 1826 UNRESOLVED -> PASS
>>> - 102 UNRESOLVED -> XFAIL
>>>
>>> as visible in the red cell at
>>> http://people.linaro.org/~christophe.lyon/cross-validation/gcc-test-patches/248552-gnu-stubs9.patch/report-build-info.html
>>> (the build-failed line can be ignored, it was caused by a server
>>> problem)
>>>
>>> Sorry, the explanation is almost longer than the patch :-)
>>>
>>> Is it OK for trunk?
>>> (Just realizing that I forgot to document the new functions :( )
>>>
>>
>> Here is an updated version with a bit of documentation for the new
>> effective target.
>> arm_neon_ok_no_float_abi now only tries to add -mfpu=neon, not ""
>> since we always
>> add -mfpu=neon in the lto tests anyway.
>>
>> OK?
>>
>>
>>> Thanks,
>>>
>>> Christophe