[PATCH] D136136: [RISCV] Lower VECTOR_SHUFFLE to VSLIDEDOWN_VL.

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


================
Comment at: llvm/lib/Target/RISCV/RISCVISelLowering.cpp:2907
+  // Do not handle -1 here. -1 can be handled by isElementRotate.
+  if (Mask[0] == -1)
+    return SDValue();
----------------
Checking `Mask[0] < 0` would allow a faster exit for cases that obviously won't match slidedown.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136136/new/

https://reviews.llvm.org/D136136