aheejin added inline comments.

================
Comment at: llvm/test/CodeGen/WebAssembly/simd-widening.ll:113
+
+;; Also test that similar patterns are still expanded correctly
+
----------------
tlively wrote:
> aheejin wrote:
> > It'd be clearer to say starting indices of these don't start with 0 or 
> > [lanecount - 1] so they can't be widened using `widen_low` or `widen_high` 
> > instructions.
> > 
> > Question: Can we also widen these using shifts?
> Sure, since I didn't end up testing more patterns, I can make the comment 
> more specific.
> 
> Regarding shifts, I don't think it's possible to do widening with shifts 
> because widening has to fundamentally change the number of lanes, which 
> shifts can't do.
What I meant was, in case of i16x8->i32x4, the current code can widen i16x8 
input vector with elements in the indices 0 to 4. If those elements are instead 
in 1 to 5, can we first shift that to 0~4 and widen it?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D84556/new/

https://reviews.llvm.org/D84556

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