[PATCH] D90532: [TableGen] [IR] Eliminate unnecessary recursive help class.

[Paul C. Anagnostopoulos via Phabricator via llvm-commits]

Paul-C-Anagnostopoulos added a comment.

Let's see . . .

First, it's clear that we need a more powerful version of !subst. I'm starting to think about !replace. But that's a separate task. I've also got some ideas for bang operators to manipulate dags.

It looks like there are some !foreach that can be !listsplat:

  // Instruction input/output arguments for the fragment.
  list<NVPTXRegClass> ptx_regs = !foreach(tmp, regs, regclass);

The code you mentioned above:

  dag PFOperands = !if(WithStride, (ops node:$src, node:$ldm), (ops node:$src));
  // Build PatFrag that only matches particular address space.
  PatFrag IntrFrag = PatFrag<PFOperands,
                             !foreach(tmp, PFOperands, !subst(ops, Intr, tmp)),

It's more efficient simply to assign the substituted dag first:

dag PFOperandsIntr = !if(WithStride, (Intr node:$src, node:$ldm), (Intr node:$src));

We can also use the new !sub operator to make things clearer.

These NVPTX TableGen files are quite clean already.


Repository:
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https://reviews.llvm.org/D90532