[all-commits] [llvm/llvm-project] 978eb3: [DAGCombiner] Allow operand of step_vector to be n...

[junparser via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 978eb3f168be46d990da0eeec6705e7f6bd85279
      https://github.com/llvm/llvm-project/commit/978eb3f168be46d990da0eeec6705e7f6bd85279
  Author: Jun Ma <JunMa at linux.alibaba.com>
  Date:   2021-04-22 (Thu, 22 Apr 2021)

  Changed paths:
    M llvm/include/llvm/CodeGen/ISDOpcodes.h
    M llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    M llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
    M llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
    M llvm/test/CodeGen/AArch64/sve-stepvector.ll
    M llvm/test/CodeGen/RISCV/rvv/stepvector.ll

  Log Message:
  -----------
  [DAGCombiner] Allow operand of step_vector to be negative.

It is proper to relax non-negative limitation of step_vector.
Also this patch adds more combines for step_vector:
(sub X, step_vector(C)) -> (add X,  step_vector(-C))

Differential Revision: https://reviews.llvm.org/D100812