[PATCH] D24491: [DAG] Allow build_vector-to-vector_shuffle combine to combine builds from two overly-wide vectors.

[Alexey Bataev via llvm-commits]

ABataev added a subscriber: ABataev.

================
Comment at: lib/CodeGen/SelectionDAG/DAGCombiner.cpp:13054-13055
@@ +13053,4 @@
+  // only care about the low elements anyway. Pad the mask with undef.
+  for (unsigned i = NumElems; i != ShuffleNumElems; ++i)
+    Mask.push_back(-1);
+
----------------
```
if (ShuffleNumElems > NumElems)
  Mask.append(ShuffleNumElems-NumElems, -1)
```
?


https://reviews.llvm.org/D24491