[Boolean Vector, patch 1/5] Introduce boolean vector to be used as a vector comparison type

[Jeff Law]

On 10/29/2015 07:08 AM, Ilya Enkovich wrote:
> On 28 Oct 22:37, Ilya Enkovich wrote:
>> Seems the problem occurs in this check in expand_vector_operations_1:
>>
>>    /* A scalar operation pretending to be a vector one.  */
>>    if (VECTOR_BOOLEAN_TYPE_P (type)
>>        && !VECTOR_MODE_P (TYPE_MODE (type))
>>        && TYPE_MODE (type) != BLKmode)
>>      return;
>>
>> This is to filter out scalar operations on boolean vectors.
>> The problem here is that TYPE_MODE (type) doesn't return
>> V4SImode assigned to the type but calls vector_type_mode
>> instead which tries to find an integer mode for it and returns
>> TImode. This causes function exit and we don't expand vector
>> comparison.
>>
>> Suppose simple option to fix it is to change default get_mask_mode
>> hook to return BLKmode in case chosen integer vector mode is not
>> vector_mode_supported_p.
>>
>> Thanks,
>> Ilya
>>
>
> Here is a patch which fixes the problem on ARM (and on i386 with -mno-sse also).  I checked it fixes the problem on ARM and also bootstrapped and checked it on x86_64-unknown-linux-gnu.  Is it OK?
>
> Thanks,
> Ilya
> --
> gcc/
>
> 2015-10-29  Ilya Enkovich  <enkovich.gnu@gmail.com>
>
> 	* targhooks.c (default_get_mask_mode): Use BLKmode in
> 	case target doesn't support required vector mode.
> 	* stor-layout.c (layout_type): Check for BLKmode.
And just to be clear, since Richi pointed out that we're already using 
BLKmode for this kind of situation, this patch is OK.

Jeff