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tvm_tirx.backend.cuda.ptx
=========================

.. automodule:: tvm_tirx.backend.cuda.ptx
   :no-members:

.. currentmodule:: tvm_tirx.backend.cuda.ptx

Classes
-------

.. autosummary::
   :toctree: generated/

   PTXNamespace

Functions
---------

.. autosummary::
   :toctree: generated/

   instruction_forms
   instruction_name

Instruction entries
-------------------

``python/tvm_tirx/backend/cuda/ptx/table.py`` defines ``TABLE`` and its
``InstructionEntry`` records. Each entry describes one operand shape;
multiple entries may share a user-facing instruction mnemonic.

.. list-table::
   :header-rows: 1

   * - Field
     - Meaning
   * - ``operands``
     - Operand order, register or address kind, read/write direction, dtype, and register-group size.
   * - ``slots``
     - Modifier positions, legal tokens, and optional positions.
   * - ``check``, ``imm_check``
     - Checks for modifier combinations and concrete immediate values.
   * - ``asm_volatile``, ``orders_memory``
     - Inline-assembly retention and compiler memory-ordering requirements.
   * - ``cert_arch``
     - Architecture used by instruction certification tests.

Predication and special operands
--------------------------------

PTX call destinations are leading operands, and the call itself returns
no value. Inside TVMScript, the keyword-only ``pred`` gates an instruction.
For example, a predicated load can preserve the destination's existing
value when the predicate is false:

.. code-block:: python

   T.ptx.ld.global_.b32(value, pointer, pred=predicate, preserve_dst=True)

Here ``value`` must be an initialized writable destination, and
``pointer`` selects the memory to read. Special operand helpers include:

.. list-table::
   :header-rows: 1

   * - Helper
     - Meaning
   * - ``T.ptx.pred(value)``
     - Mark an operand as a PTX ``.pred`` register.
   * - ``T.ptx.addr(base, byte_offset)``
     - Form an immediate-offset address for an instruction that accepts it.
   * - ``T.ptx.SINK``
     - Supply PTX's ``_`` sink in a table-marked operand position.

Developer generators
--------------------

Run these commands from the repository root with the Python package
available:

.. code-block:: bash

   python -m tvm_tirx.backend.cuda.ptx.gen_helpers add -o /tmp/ptx_add.cuh
   python -m tvm_tirx.backend.cuda.ptx.gen_stubs -o /tmp/ptx_stubs.pyi
   python -m tvm_tirx.backend.cuda.ptx.gen_coverage > /tmp/ptx_coverage.txt

``gen_helpers`` renders the selected family's supported instruction forms.
``gen_stubs`` generates signatures for editor tooling, and ``gen_coverage``
reports instruction families and variants. These files support inspection;
runtime code generation reads the instruction table directly. Each command's
``--help`` describes its available options. The :doc:`PTX TableGen guide
</dev/cuda/ptx_tablegen>` follows an instruction through the implementation.