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Re: Problem exposed by recent ARM multiply changes
> On Sep 26, 2019, at 12:01 PM, Jeff Law <law@redhat.com> wrote:
>
> On 9/26/19 9:47 AM, Jakub Jelinek wrote:
>> On Thu, Sep 26, 2019 at 09:39:31AM -0600, Jeff Law wrote:
>>> Right. My point is that the multiplication patterns are an exception as
>>> well.
>>
>> Do you have some evidence for that?
> It's in the manual. And yes it potentially makes a huge mess due to the
> interactions with modeless CONST_INTs.
Do you mean things like "mulhisi3"?
That's a pattern for a multiplication whose output is longer than its inputs. But the RTL it builds has a regular mult insn with equal length operands (all SImode in this example), with sign_extend insns in the mult source operands. So I don't believe that contradicts what Jakub said.
paul