[PATCH] D132374: [TTI] Add SK_Splice shuffle mask detection and X86 costs

[Florian Hahn via Phabricator via llvm-commits]

fhahn added inline comments.


================
Comment at: llvm/lib/IR/Instructions.cpp:2309
+    // Splice is sequential starting from StartIndex.
+    if (MaskEltVal != (StartIndex + I))
+      return false;
----------------
Do we also need to check if we are extracting exactly half the original elements here? I see `isSplice` checks the length isn't changed, but other calls of `isSpliceMask` don't seem to do it (in BasicTTI)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D132374/new/

https://reviews.llvm.org/D132374