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Re: S/390: Fix warnings in "*setmem_long..." patterns.
- From: Andreas Krebbel <krebbel at linux dot vnet dot ibm dot com>
- To: Ulrich Weigand <uweigand at de dot ibm dot com>
- Cc: gcc-patches at gcc dot gnu dot org, vogt at linux dot vnet dot ibm dot com
- Date: Wed, 2 Dec 2015 14:18:54 +0100
- Subject: Re: S/390: Fix warnings in "*setmem_long..." patterns.
- Authentication-results: sourceware.org; auth=none
- References: <20151202125141 dot 9BF6CF8BB at oc7340732750 dot ibm dot com> <565EEE13 dot 3010405 at linux dot vnet dot ibm dot com>
On 12/02/2015 02:11 PM, Andreas Krebbel wrote:
> On 12/02/2015 01:51 PM, Ulrich Weigand wrote:
>> Andreas Krebbel wrote:
>>> On 12/02/2015 11:12 AM, Dominik Vogt wrote:
>>>> Hopefully, this is correct now; it does pass the functional test case
>>>> that's part of the patch. Unfortunately the define_insn patters
>>>> had to be duplicated because of the new subreg offsets.
>>>
>>> The number of patterns could possibly be reduced using the define_subst machinery. I'm looking into
>>> this for some other changes. No need to do this right now. We can do this later on-top.
>>
>> For this particular issue, shouldn't a simple mode_attr be OK?
>> I see that the sh port uses this:
>>
>> (define_mode_attr lowpart_be [(QI "3") (HI "2")])
>>
>> [(set (reg:SI T_REG)
>> (eq:SI
>> (subreg:QIHI
>> (and:SI (match_operand:SI 0 "arith_reg_operand")
>> (match_operand:SI 1 "arith_reg_operand")) <lowpart_be>)
>> (const_int 0)))]
>
> Unfortunately in our case the attribute value doesn't only depend on the mode. It also depends on
> zarch/esa. We would need some kind of conditional attribute.
However, we could probably at least merge the two zarch variants.
The define_subst is probably the right thing for adding the AND around the padding byte operand.
Bye,
-Andreas-