[PATCH] D49924: [DAGCombiner] transform sub-of-shifted-signbit to add

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added inline comments.


================
Comment at: lib/CodeGen/SelectionDAG/DAGCombiner.cpp:2742
   }
 
+  if (!LegalOperations && N1.getOpcode() == ISD::SRL && N1.hasOneUse()) {
----------------
```
// sub N0, (lshr N10, width-1)  ->  add N0, (ashr N10, width-1)
```


https://reviews.llvm.org/D49924