[llvm-commits] [llvm] r124145 - in /llvm/trunk/utils/TableGen: CodeGenDAGPatterns.cpp CodeGenDAGPatterns.h

[David A. Greene]

Evan Cheng <evan.cheng at apple.com> writes:

> Hi David,
>
> What's your plan? Please elaborate.

I'm about to add an INSERT_SUBVECTOR operation for SelectionDAGs.  This,
along with the existing EXTRACT_SUBVECTOR operation, will be matched to
VINSERTF128/VEXTRACTF128, respectively.  I tried writing various other
patterns to match to those instructions but this is by far the cleanest
way I could come up with.

There was no type checking in TableGen for EXTRACT_SUBVECTOR, so this
and following patches add it.  It helped a lot to have TableGen catch
type errors as I implemented patterns.

The next commit will include default implementations for
INSERT_SUBVECTOR/EXTRACT_SUBVECTOR by going through the stack, similar
to what's done for BUILD_VECTOR.

                                -Dave