[PATCH] D46493: [DagCombiner] Not all 'andn''s work with immediates.

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

In https://reviews.llvm.org/D46493#1089097, @andreadb wrote:

> > I'd say this regression is an improvement, since IPC increased in that case?
>
> As a rule of thumb when using llvm-mca, it's best to always remove return statements from the assembly code sequence.
>  llvm-mca should have warned you about the presence of a return statement in the input sequence:
>
>   warning: found a return instruction in the input assembly sequence.
>   note: program counter updates are ignored.
>
>
> To get the correct resource pressure distribution in example icmp-opt.txt, you should remove the `retq`.


Thank you for your comments!
I will filter it out, so hopefully in future my mca expirience will be better :)

In https://reviews.llvm.org/D46493#1089097, @andreadb wrote:

> If you run multiple iterations and print the timeline view, you can see how the "average wait time" in the scheduler's queue is quite high for the shlq instruction.


Aha, so far i kinda ignored `-timeline` switch.
Those flags need work i think. I have just tried enabling them all, and it seems like they invert the current state?
I'd like to 1. have a switch to turn them all on, 2. maybe print which ones are currently enabled in `-help`


Repository:
  rL LLVM

https://reviews.llvm.org/D46493