[PATCH] D48491: [X86] Select BEXTR when there is only BMI1.

Mon Sep 17 03:28:23 PDT 2018

RKSimon added a comment.

In https://reviews.llvm.org/D48491#1236464, @lebedev.ri wrote:

> In https://reviews.llvm.org/D48491#1236394, @craig.topper wrote:
>
> > Can we DAG combine to X86ISD::BEXTR for these cases? Then we can properly check one use of the inner parts of the pattern.
>
>
> Do we care whether the *entire* old patter goes away, or just one more instruction?
>  But yes, should work, let's see.

Hopefully combining in DAG would help https://bugs.llvm.org/show_bug.cgi?id=38938.

Not sure if we should allow TBM BEXTR (imm) more leniently than BMI1 BEXTR (reg)?

Repository:
  rL LLVM

https://reviews.llvm.org/D48491