On 27/05/15 09:39, Andrew Pinski wrote:
> On Wed, May 27, 2015 at 4:38 PM, Kyrill Tkachov <kyrylo.tkachov@arm.com> wrote:
>> Ping.
>> https://gcc.gnu.org/ml/gcc-patches/2015-05/msg00054.html
> This and the one in AARCH64 is too noisy.  Can we have an option to
> turn this on and default to turning them off.

How about this? The new undocumented option can be used to turn on verbose costs dumping.
It is off by default.

Tested arm-none-eabi.

Ok for trunk?

Thanks,
Kyrill

2015-06-16  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

     * config/arm/arm.c (DBG_COST): New macro.
     (arm_new_rtx_costs): Use above.
     * config/arm/arm.opt (mdebug-rtx-costs): New option.

> Thanks,
> Andrew
>
>> Thanks,
>> Kyrill
>>
>> On 01/05/15 15:31, Kyrill Tkachov wrote:
>>> Hi all,
>>>
>>> This patch adds a macro to wrap cost field accesses into a helpful debug
>>> dump,
>>> saying which field is being accessed at what line and with what values.
>>> This helped me track down cases where the costs were doing the wrong thing
>>> by allowing me to see which path in arm_new_rtx_costs was taken.
>>> For example, the combine log might now contain:
>>>
>>> Trying 2 -> 6:
>>> Successfully matched this instruction:
>>> (set (reg:SI 115 [ D.5348 ])
>>>        (neg:SI (reg:SI 0 r0 [ a ])))
>>> using extra_cost->alu.arith with cost 0 from line 10506
>>>
>>> which can be useful in debugging the rtx costs.
>>>
>>> Bootstrapped and tested on arm.
>>>
>>> Ok for trunk?
>>>
>>> Thanks,
>>> Kyrill
>>>
>>>
>>> 2015-05-01  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
>>>
>>>        * config/arm/arm.c (DBG_COST): New macro.
>>>        (arm_new_rtx_costs): Use above.
>>