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

[Kyrill Tkachov <kyrylo.tkachov@foss.arm.com>]

Hi Christophe,

On 07/06/17 10:13, Christophe Lyon 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?
>

This is ok.
Sorry for the delay.

Kyrill

>> Thanks,
>>
>> Christophe