[all-commits] [llvm/llvm-project] 4a3708: [SDAG] remove shift that is redundant with part of...

[Sanjay Patel via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 4a3708cd6b062a6afe2697cc8b39329e3f2faa25
      https://github.com/llvm/llvm-project/commit/4a3708cd6b062a6afe2697cc8b39329e3f2faa25
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2022-02-24 (Thu, 24 Feb 2022)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    M llvm/test/CodeGen/AArch64/funnel-shift.ll
    M llvm/test/CodeGen/RISCV/rv32zbp.ll
    M llvm/test/CodeGen/X86/funnel-shift.ll

  Log Message:
  -----------
  [SDAG] remove shift that is redundant with part of funnel shift

This is the SDAG translation of D120253 :
https://alive2.llvm.org/ce/z/qHpmNn

The SDAG nodes can have different operand types than the result value.
We can see an example of that with AArch64 - the funnel shift amount
is an i64 rather than i32.

We may need to make that match even more flexible to handle
post-legalization nodes, but I have not stepped into that yet.

Differential Revision: https://reviews.llvm.org/D120264