LDC 1.5-1.6 huge degradation of optimization

[kinke]

On Friday, 1 December 2017 at 04:30:52 UTC, Igor Shirkalin wrote:
> On Thursday, 30 November 2017 at 22:58:10 UTC, Joakim wrote:
>> On Thursday, 30 November 2017 at 16:01:19 UTC, kinke wrote:
>>> On Thursday, 30 November 2017 at 15:25:31 UTC, Igor Shirkalin 
>>> wrote:
>>>> It's now obvious the reason of this regression is LLVM 5.0.0
>>>> Does it mean it's not time to move to latest LLVM for the 
>>>> latest LDC?
>>>
>>> 5.0.0 *is* the latest released version. 5.0.1 is about to be 
>>> released these days, but whether it'll fix this issue is 
>>> uncertain. As is whether it's fixed in current LLVM master 
>>> (6.0.0). LLVM is a huge piece of software, bugs and 
>>> regressions are to be expected.
>>
>> I too read it the way you did, that llvm needs to be updated 
>> forward, but I think he meant ldc should stick with 4.0.1 for 
>> now.
>
> Right. Exactly what I meant. Excuse for some irrational English.

No worries. One performance regression is by no means enough to 
convince me to step back, especially since anyone is free to 
compile LDC himself and use LLVM versions as old as 3.7 if they 
like.