[PATCH] D48326: [RFC] "Alternative" matches for TableGen DAG patterns

[Ulrich Weigand via Phabricator via llvm-commits]

uweigand added a comment.

In https://reviews.llvm.org/D48326#1136809, @kparzysz wrote:

> I don't think that the new keyword is necessary.  Why not have a new class `Patterns`that takes a list of input dag patterns (otherwise identical to the current `Pattern`), and matches when any of these inputs matches?  Then you can have a `PatFrags` as an analogy to `PatFrag`.


I'm not sure I fully see how this would work yet, but I'll give it a try.  Note that the primary motivation of my change was specifically to allow multiple matching patterns for the the main **instruction** pattern, i.e. the `Pattern` field of the `Instruction` class, and I'm not sure I see how your suggestion can work for this case, given that the main pattern does operate a bit differently from the `Pattern` case ...


Repository:
  rL LLVM

https://reviews.llvm.org/D48326