[all-commits] [llvm/llvm-project] 1ac9b5: [RISCV] Lower GREVI and GORCI as custom nodes

[Fraser Cormack via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 1ac9b548310c22ee558f04dd49d08ace0ccfb568
      https://github.com/llvm/llvm-project/commit/1ac9b548310c22ee558f04dd49d08ace0ccfb568
  Author: Fraser Cormack <fraser at codeplay.com>
  Date:   2020-11-19 (Thu, 19 Nov 2020)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVISelLowering.cpp
    M llvm/lib/Target/RISCV/RISCVISelLowering.h
    M llvm/lib/Target/RISCV/RISCVInstrInfoB.td
    M llvm/test/CodeGen/RISCV/rv64Zbp.ll

  Log Message:
  -----------
  [RISCV] Lower GREVI and GORCI as custom nodes

This moves the recognition of GREVI and GORCI from TableGen patterns
into a DAGCombine. This is done primarily to match "deeper" patterns in
the future, like (grevi (grevi x, 1) 2) -> (grevi x, 3).

TableGen is not best suited to matching patterns such as these as the compile
time of the DAG matchers quickly gets out of hand due to the expansion of
commutative permutations.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D91259