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Re: [PATCH GCC]Look into unnecessary conversion when checking mult_op in get_shiftadd_cost
- From: "Bin.Cheng" <amker dot cheng at gmail dot com>
- To: Richard Biener <richard dot guenther at gmail dot com>
- Cc: Bin Cheng <bin dot cheng at arm dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Tue, 15 Sep 2015 13:53:06 +0800
- Subject: Re: [PATCH GCC]Look into unnecessary conversion when checking mult_op in get_shiftadd_cost
- Authentication-results: sourceware.org; auth=none
- References: <000c01d0e532$823066c0$86913440$ at arm dot com> <CAFiYyc0R-1QjWqz9WKydr9wRUdLdv9oPtBFXUo64TNeoFF1o9A at mail dot gmail dot com>
On Wed, Sep 2, 2015 at 8:32 PM, Richard Biener
<richard.guenther@gmail.com> wrote:
> On Wed, Sep 2, 2015 at 5:50 AM, Bin Cheng <bin.cheng@arm.com> wrote:
>> Hi,
>> When calling get_shiftadd_cost, the mult_op is stripped at caller places.
>> We should look into unnecessary conversion in op1 before checking equality,
>> otherwise it computes wrong shiftadd cost. This patch picks this small
>> issue up.
>>
>> Bootstrap and test on x86_64 and aarch64 along with other patches. Is it
>> OK?
>
> Just do STRIP_NOPS (op1) unconditionally? Thus
>
> STRIP_NOPS (op1);
> mult_in_op1 = operand_equal_p (op1, mult, 0);
>
> ok with that change.
Patch committed as suggested.
Thanks,
bin