[PINGv2][PATCHv3] Fix vector tests on ARM platforms with disabled unaligned accesses

[Marat Zakirov]

On 07/31/2014 04:08 PM, Marat Zakirov wrote:
>
> On 07/24/2014 07:40 PM, Marat Zakirov wrote:
>>
>> On 07/24/2014 04:27 PM, Marat Zakirov wrote:
>>>
>>> On 07/23/2014 06:23 PM, Marat Zakirov wrote:
>>>> Hi there!
>>>>
>>>> I made a patch which fixes regressions on ARM platforms with 
>>>> disabled unaligned accesses. The problem is that 
>>>> 'arm_vect_no_misalign' predicate do not check 'unaligned_access' 
>>>> global variable to determine whether unaligned access to vector are 
>>>> allowed. This leads to spurious vect.exp test fails when GCC is 
>>>> configured --with-specs=%{!munaligned-access:-mno-unaligned-access}.
>>>>
>>>> Attached patch fixes ARM predicate and several tests to correctly 
>>>> handle the issue.
>>>>
>>>> The following targets were reg. tested for multiple targets (ARM, 
>>>> Thumb-1, Thumb-2, x86, x86_64) with and without 
>>>> -mno-unaligned-access.  Analysis showed patch affects only vect.exp 
>>>> tests so only vect.exp was tested.
>>>>
>>>> For x86, x86_64,  ARM without -mno-unaligned-access, Thumb-2 
>>>> without -mno-unaligned-access and Thumb-1 no regressions occured. 
>>>> For ARM/Thumb2 with -mno-unaligned-access patch fixed most of 
>>>> failures but triggered some problems (see attached log) for current 
>>>> vect.exp tests:
>>>> 1) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61887
>>>> 2) Some XPASS'es due to unexpected loop versioning (e.g. 
>>>> gcc.dg/vect/pr33804.c).
>>>> 3) After predicate fix some passing tests which require unaligned 
>>>> vector support become NA (this was expected).
>>>>
>>> Here is new version of patch and regression log. On the current 
>>> trunk results are slightly different due to patches for Richard 
>>> Biener (no UNRESOLVED fails) but some PASS->XPASS regressions still 
>>> remain (see attachment):
>>>
>>> PASS->XPASS: gcc.dg/vect/if-cvt-stores-vect-ifcvt-18.c 
>>> scan-tree-dump-times vect "vectorized 1 loops" 1
>>> PASS->XPASS: gcc.dg/vect/pr33804.c -flto -ffat-lto-objects 
>>> scan-tree-dump-times vect "vectorized 1 loops" 1
>>> etc.
>>>
>>> These XPASS'es are due to code versioning: current GCC creates 2 
>>> versions of loop: aligned and misaligned. It's look like they are 
>>> slightly out of date at lest for ARM.
>>>
>>
>> On 07/24/2014 06:50 PM, Ramana Radhakrishnan wrote:
>>> This is redundant.
>>>
>>>> -           || (defined(__ARMEL__) \
>>>> +           || (defined(__ARM_FEATURE_UNALIGNED) \
>>>> +               && defined(__ARMEL__) \
>>>>                  && (!defined(__thumb__) || defined(__thumb2__)))
>>> As is this line.
>>>
>>> I think you can restrict the check to defined(__ARM_FEATURE_UNALIGNED)
>>> && defined(__ARMEL__)
>>>
>>>   __ARM_FEATURE_UNALIGNED should tell you whether unaligned access is
>>> allowed or not, therefore you should no longer require any specific
>>> "architectural" checks.
>>>
>>>
>>>>          #error FOO
>>>>          #endif
>>>>
>>> I'm not sure about the original intent of the tests right now.
>>>
>>> Ramana
>>>
>>
>> Thank you Ramana!
>>
>> --Marat
>

-------------- next part --------------
A non-text attachment was scrubbed...
Name: unalign3.diff
Type: text/x-patch
Size: 2663 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20140807/8e9e2729/attachment.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: arm_regs3.log
Type: text/x-log
Size: 30736 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20140807/8e9e2729/attachment-0001.bin>