[PATCH] D19198: [X86][AVX] Generalized matching for target shuffle combines

[Elena Demikhovsky via llvm-commits]

delena added a comment.

Please see my comments above about UNPCK and FloatDomain.


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Comment at: lib/Target/X86/X86ISelLowering.cpp:24067
@@ +24066,3 @@
+    if (Mask.equals({0, 0, 2, 2, 4, 4, 6, 6})) {
+      Shuffle = X86ISD::MOVDDUP;
+      ShuffleVT = MVT::v8f64;
----------------
RKSimon wrote:
> delena wrote:
> > Can you keep the original VT here?
> Annoyingly no but between bitcast combines and target shuffle combines it doesn't seem to cause any problems.
The type may vary from v16f32 to v16i32, or from v8i64 to v8f64, but the vector should remain the same. Otherwise we can't put mask on this operation.


Repository:
  rL LLVM

http://reviews.llvm.org/D19198