[PATCH][RFC] Radically simplify emission of balanced tree for switch statements.

[Jeff Law]

On 01/09/2018 07:43 AM, Martin Liška wrote:
> On 09/20/2017 05:00 PM, Jeff Law wrote:
>> On 09/20/2017 01:24 AM, Martin Liška wrote:
>>
>>>
>>> Hello.
>>>
>>> Thank you Jeff for very verbose explanation what's happening. I'm planning to do
>>> follow-up of this patch that will include clustering for bit-tests and jump tables.
>>> Maybe that will make aforementioned issues even more difficult, but we'll see.
>> FWIW, the DOM changes to simplify the conditionals seem to help both
>> cases, trigger reasonably consistently in a bootstrap and for some
>> subset of the triggers actually result in transformations that allow
>> other passes to do a better job in the common (-O2) case.  So my
>> inclination is to polish them a bit further get them on the trunk.
>>
>> My recommendation is to ignore the two regressions for now and focus on
>> the cleanups you're trying to do.
>>
>> jeff
>>
> 
> Hello.
> 
> Some time ago I've decided that I'll make patch submission of switch clustering
> in next stage1. However, this patch can be applied as is in this stage3. Would
> it be possible or is it too late?
I'll let Richi make the call here.  FWIW, the DOM changes to avoid the
two missed-optimization regressions you ran into are on the trunk, so
that's no longer a blocking issue.

jeff