Re: [PATCH AArch64]Fix test failure for pr84682-2.c

["Bin.Cheng" <amker dot cheng at gmail dot com>]

On Sat, Mar 17, 2018 at 8:54 AM, Richard Sandiford
<richard.sandiford@linaro.org> wrote:
> Kyrill  Tkachov <kyrylo.tkachov@foss.arm.com> writes:
>> Hi Bin,
>>
>> On 16/03/18 11:42, Bin Cheng wrote:
>>> Hi,
>>> This simple patch fixes test case failure for pr84682-2.c by returning
>>> false on wrong mode rtx in aarch64_classify_address, rather than assert.
>>>
>>> Bootstrap and test on aarch64.  Is it OK?
>>>
>>> Thanks,
>>> bin
>>>
>>> 2018-03-16  Bin Cheng  <bin.cheng@arm.com>
>>>
>>>         * config/aarch64/aarch64.c (aarch64_classify_address): Return false
>>>         on wrong mode rtx, rather than assert.
>>
>> This looks ok to me in light of
>> https://gcc.gnu.org/ml/gcc-patches/2018-03/msg00633.html
>> This function is used to validate inline asm operands too, not just
>> internally-generated addresses.
>> Therefore all kinds of garbage must be rejected gracefully rather than ICEing.
>>
>> You'll need an approval from an AArch64 maintainer though.
>
> IMO we should make address_operand itself check something like:
>
>   (GET_MODE (x) == VOIDmode || SCALAR_INT_MODE_P (GET_MODE (x)))
>
> Target-independent code fundamentally assumes that an address will not
> be a float, so I think the check should be in target-independent code
> rather than copied to each individual backend.
>
> This was only caught on aarch64 because we added the assert, but I think
> some backends ignore the mode of the address and so would actually accept
> simple float rtxes.
Hi Richard,
Thanks for the suggestion generalizing the fix.  Here is the updated patch.
Bootstrap and test on x86_64 and AArch64, is it OK?

Thanks,
bin

2018-03-22  Bin Cheng  <bin.cheng@arm.com>

    * recog.c (address_operand): Return false on wrong mode for address.
    * config/aarch64/aarch64.c (aarch64_classify_address): Remove assert
    since it's checked in general code now.

>
> Thanks,
> Richard

Attachment: patch-pr84682-2-20180319.txt
Description: Text document