[PATCH] D120264: [SDAG] remove shift that is redundant with part of funnel shift

[Sanjay Patel via Phabricator via llvm-commits]

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This is the SDAG translation of D120253 <https://reviews.llvm.org/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.


https://reviews.llvm.org/D120264

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

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