llvm/docs/GlobalISel/Porting.rst

   1 .. _porting:
   2
   3 Porting GlobalISel to A New Target
   4 ==================================
   5
   6 There are four major classes to implement by the target:
   7
   8 * :ref:`CallLowering <translator-call-lower>` --- lower calls, returns, and
   9   arguments according to the ABI.
  10 * :ref:`RegisterBankInfo <api-registerbankinfo>` --- describe
  11   :ref:`gmir-regbank` coverage, cross-bank copy cost, and the mapping of
  12   operands onto banks for each instruction.
  13 * :ref:`LegalizerInfo <api-legalizerinfo>` --- describe what is legal, and how
  14   to legalize what isn't.
  15 * :ref:`InstructionSelector <api-instructionselector>` --- select generic MIR
  16   to target-specific MIR.
  17
  18 Additionally:
  19
  20 * ``TargetPassConfig`` --- create the passes constituting the pipeline,
  21   including additional passes not included in the :ref:`pipeline`.
  22
  23 Tutorials
  24 =========
  25
  26 We'd recommend watching `this tutorial
  27 <https://www.llvm.org/devmtg/2017-10/#tutorial2>`_ from the 2017 LLVM DevMeeting
  28 which gave an overview of how to bring up a new backend in GlobalISel.