A register class can appear as a leaf TreePatternNode with and without a
name:
(COPY_TO_REGCLASS GPR:$src, F8RC)
In a named leaf node like GPR:$src, the register class provides type
information for the named variable represented by the node. The TypeSet
for such a node is the set of value types that the register class can
represent.
In an unnamed leaf node like F8RC above, the register class represents
itself as a kind of immediate. Such a node has the type MVT::i32,
we'll never create a virtual register representing it.
This change makes it possible to remove the special handling of
COPY_TO_REGCLASS in CodeGenDAGPatterns.cpp.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177825 91177308-0d34-0410-b5e6-96231b3b80d8
7a42fb3b6e