[PATCH] D111960: [X86][AVX] Prefer VINSERTF128 over VPERM2F128 for 128->256 subvector concatenations

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


================
Comment at: llvm/test/CodeGen/X86/pr50823.ll:11-13
+; CHECK-NEXT:    vmovups (%rsi), %ymm0
+; CHECK-NEXT:    vinsertf128 $1, 32(%rsi), %ymm0, %ymm0
+; CHECK-NEXT:    vhaddps %ymm0, %ymm0, %ymm0
----------------
pengfei wrote:
> Is this a regression?
I don't believe so: https://simd.godbolt.org/z/rhrqsss5a - as I said in the summary, vinsertX128 tends to be cheaper than more general cross-lane shuffles.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D111960/new/

https://reviews.llvm.org/D111960