llvm-project/llvm/docs/GlobalISel/Porting.rst

.. _porting:

Porting GlobalISel to A New Target
==================================

There are four major classes to implement by the target:

* :ref:`CallLowering <translator-call-lower>` --- lower calls, returns, and
  arguments according to the ABI.
* :ref:`RegisterBankInfo <api-registerbankinfo>` --- describe
  :ref:`gmir-regbank` coverage, cross-bank copy cost, and the mapping of
  operands onto banks for each instruction.
* :ref:`LegalizerInfo <api-legalizerinfo>` --- describe what is legal, and how
  to legalize what isn't.
* :ref:`InstructionSelector <api-instructionselector>` --- select generic MIR
  to target-specific MIR.

Additionally:

* ``TargetPassConfig`` --- create the passes constituting the pipeline,
  including additional passes not included in the :ref:`pipeline`.

Tutorials
=========

We'd recommend watching `this tutorial
<https://www.llvm.org/devmtg/2017-10/#tutorial2>`_ from the 2017 LLVM DevMeeting
which gave an overview of how to bring up a new backend in GlobalISel.
[globalisel] Restructure the GlobalISel documentation There's a couple minor deletions amongst this but 99% of it is just moving the documentation around to prepare the way for more meaningful changes. 2019-10-26 06:50:36 +08:00			`.. _porting:`

			`Porting GlobalISel to A New Target`
			`==================================`

			`There are four major classes to implement by the target:`

[globalisel][docs] Fix a label that was renamed 2019-10-31 02:47:12 +08:00			* :ref:`CallLowering <translator-call-lower>` --- lower calls, returns, and
			`arguments according to the ABI.`
[globalisel] Restructure the GlobalISel documentation There's a couple minor deletions amongst this but 99% of it is just moving the documentation around to prepare the way for more meaningful changes. 2019-10-26 06:50:36 +08:00			* :ref:`RegisterBankInfo <api-registerbankinfo>` --- describe
			:ref:`gmir-regbank` coverage, cross-bank copy cost, and the mapping of
			`operands onto banks for each instruction.`
			* :ref:`LegalizerInfo <api-legalizerinfo>` --- describe what is legal, and how
			`to legalize what isn't.`
			* :ref:`InstructionSelector <api-instructionselector>` --- select generic MIR
			`to target-specific MIR.`

			`Additionally:`

			* ``TargetPassConfig`` --- create the passes constituting the pipeline,
			including additional passes not included in the :ref:`pipeline`.
[globalisel][docs] Add the tutorial to the Porting document In lieu of converting that tutorial to text, add a link to the porting tutorial from the 2017 Dev Meeting to the porting page 2019-10-31 05:52:57 +08:00
			`Tutorials`
			`=========`

			We'd recommend watching `this tutorial
			<https://www.llvm.org/devmtg/2017-10/#tutorial2>`_ from the 2017 LLVM DevMeeting
			`which gave an overview of how to bring up a new backend in GlobalISel.`