[PATCH] D40497: [PowerPC] Partially enable the ISEL expansion pass.

[Zaara Syeda via Phabricator via llvm-commits]

syzaara added inline comments.


================
Comment at: lib/Target/PowerPC/PPCExpandISEL.cpp:279
     // Special case 2, the two input registers used by ISEL are the same.
     // Note 1: We favor merging ISEL expansions over folding a single one. If
     // the passed list has multiple merge-able ISEL's, we won't fold any.
----------------
jtony wrote:
> syzaara wrote:
> > It seems that Note 1 is no longer satisfied since you have already folded the ISELs in expandAndMergeISELs.
> Same here.
If we have the case of:
foldable isel
foldable isel
regular isel

where both the foldable isels can be merged, previously with expansion enabled, we would merge them. Now, with the expansion enabled, they will be changed to move registers before. So we won't be getting the same behavior with the expansion enabled, making this comment invalid.


https://reviews.llvm.org/D40497