On Mon, Nov 6, 2017 at 12:19 AM, Peryt, Sebastian
<sebastian.pe...@intel.com> wrote:
>> On Sun, Nov 5, 2017 at 12:14 PM, Peryt, Sebastian <sebastian.pe...@intel.com>
>> wrote:
>> > Hi,
>> >
>> > After r253934 gcc.target/i386/pr71321.c started to fail due to the wrong
>> number of scan-assembler - 2 instead of 3. This patch is fixing that.
>>
>> Are you sure that there is no problem with the code generation? Did you
>> investigate original PR for what it is testing and why it is testing for
>> these 3
>> LEAs?
>
> Well, the problem is due to the change in cost model. This can be reverted by
> simple modification:
>
> diff --git a/gcc/config/i386/x86-tune-costs.h
> b/gcc/config/i386/x86-tune-costs.h
> index c7ac70e..bb5b3e2 100644
> --- a/gcc/config/i386/x86-tune-costs.h
> +++ b/gcc/config/i386/x86-tune-costs.h
> @@ -2253,7 +2253,7 @@ struct processor_costs core_cost = {
> COSTS_N_INSNS (4), /* DI */
> COSTS_N_INSNS (4)}, /* other */
> 0, /* cost of multiply per each bit set
> */
> - {COSTS_N_INSNS (8), /* cost of a divide/mod for QI */
> + {COSTS_N_INSNS (18), /* cost of a divide/mod for QI */
> COSTS_N_INSNS (8), /* HI */
> /* 8-11 */
> COSTS_N_INSNS (11), /* SI */
>
> The original PR was to make better code generation when dividing and modulo
> small integers.
>
> Ok, maybe I missed something. I'll get back to PR and see if any other
> solution will be proposed
> since for now I have nothing.
Please also note that this testcase is intended for generic cost
model, and you are testing --with-cpu=corei7. The testcase can be
"fixed" by adding "-mtune=generic", but please investigate the tuning
change anyway.
Uros.
>> > 2017-11-05 Sebastian Peryt <sebastian.pe...@intel.com>
>> >
>> > PR testsuite/82767
>> > * gcc.target/i386/pr71321.c: Fix invalid testcase.
>>
>> There is nothing wrong with the testcase.
>>
>> > Is it ok for trunk?
>> >
>> > Thanks,
>> > Sebastian
>> >
