llvm-mirror/docs/AMDGPU/gfx9_waitcnt.rst

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    *   Automatically generated file, do not edit!   *
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.. _amdgpu_synid_gfx9_waitcnt:

waitcnt
=======

Counts of outstanding instructions to wait for.

The bits of this operand have the following meaning:

    ========== ========= ================================================ ============
    High Bits  Low Bits  Description                                      Value Range
    ========== ========= ================================================ ============
    15:14      3:0       VM_CNT: vector memory operations count.          0..63
    \-         6:4       EXP_CNT: export count.                           0..7
    \-         11:8      LGKM_CNT: LDS, GDS, Constant and Message count.  0..15
    ========== ========= ================================================ ============

This operand may be specified as one of the following:

* An :ref:`integer_number<amdgpu_synid_integer_number>` or an :ref:`absolute_expression<amdgpu_synid_absolute_expression>`. The value must be in the range 0..0xFFFF.
* A combination of *vmcnt*, *expcnt*, *lgkmcnt* and other values described below.

    ====================== ======================================================================
    Syntax                 Description
    ====================== ======================================================================
    vmcnt(<*N*>)           A VM_CNT value. *N* must not exceed the largest VM_CNT value.
    expcnt(<*N*>)          An EXP_CNT value. *N* must not exceed the largest EXP_CNT value.
    lgkmcnt(<*N*>)         An LGKM_CNT value. *N* must not exceed the largest LGKM_CNT value.
    vmcnt_sat(<*N*>)       A VM_CNT value computed as min(*N*, the largest VM_CNT value).
    expcnt_sat(<*N*>)      An EXP_CNT value computed as min(*N*, the largest EXP_CNT value).
    lgkmcnt_sat(<*N*>)     An LGKM_CNT value computed as min(*N*, the largest LGKM_CNT value).
    ====================== ======================================================================

These values may be specified in any order. Spaces, ampersands and commas may be used as optional separators.

*N* is either an
:ref:`integer number<amdgpu_synid_integer_number>` or an
:ref:`absolute expression<amdgpu_synid_absolute_expression>`.

Examples:

.. parsed-literal::

    vm_cnt = 1
    exp_cnt = 2
    lgkm_cnt = 3
    cnt = vm_cnt | (exp_cnt << 4) | (lgkm_cnt << 8)

    s_waitcnt cnt
    s_waitcnt 1 | (2 << 4) | (3 << 8)                          // the same as above
    s_waitcnt vmcnt(1) expcnt(2) lgkmcnt(3)                    // the same as above
    s_waitcnt vmcnt(vm_cnt) expcnt(exp_cnt) lgkmcnt(lgkm_cnt)  // the same as above

    s_waitcnt vmcnt(1)
    s_waitcnt expcnt(2) lgkmcnt(3)
    s_waitcnt vmcnt(1), expcnt(2), lgkmcnt(3)
    s_waitcnt vmcnt(1) & lgkmcnt_sat(100) & expcnt(2)