[PATCH] D17850: Power9 - Implement byte comparison and count trailing zero instructions

[Nemanja Ivanovic via llvm-commits]

nemanjai added inline comments.

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Comment at: lib/Target/PowerPC/PPC.td:160
@@ -154,2 +159,3 @@
+                   "Enable count trailing zeros instructions">;
 
 def DeprecatedDST    : SubtargetFeature<"", "DeprecatedDST", "true",
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kbarton wrote:
> I don't see the need for adding a subtarget feature for these instructions. Why is this necessary?
It is not necessary to add individual features for these instructions. However, it doesn't seem right to guard these by the only existing Power9 features (namely Power9Vector, Power9Altivec). Also, adding a single feature for all Power9 scalar instructions seems to break with tradition.
Could you please suggest an alternative to defining these two features?


Repository:
  rL LLVM

http://reviews.llvm.org/D17850