[PATCH] D50165: [X86] Add a DAG combine for the __builtin_parity idiom used by clang to enable better codegen

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


================
Comment at: lib/Target/X86/X86ISelLowering.cpp:34720
+      (VT != MVT::i64 || (Subtarget.is64Bit() && Subtarget.hasPOPCNT())))
+    return SDValue();
+
----------------
isOperationLegal() ?


================
Comment at: lib/Target/X86/X86ISelLowering.cpp:34732
+  if (!N1C || !N1C->getAPIntValue().isOneValue())
+    return SDValue();
+
----------------
```
if (!isOneConstant(N1))
  return SDValue();
```


https://reviews.llvm.org/D50165