Changes between Version 5 and Version 6 of GcnState


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Timestamp:
Jun 4, 2017, 4:00:31 PM (2 years ago)
Author:
trac
Comment:

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  • GcnState

    v5 v6  
    458458<p>The initial value of FP_ROUND and FP_DENORM fields (first 8 bits in MODE register)
    459459can be given by including .floatmode pseudo-operation.</p>
     460<h3>GPR indexing mode (GCN 1.2)</h3>
     461<p>The GCN 1.2 introduces the GPR indexing mode that facilitate usage of indexing in VGPR's.
     462The bit 27 in MODE register indicates whether this mode is enabled.
     463The M0 register holds index and mode of GPR indexing. If this mode will be enabled
     464then this index will be added to index of specified VGPR used in vector instruction.
     465The mode specifies to which operand of vector instruction a GPR index will be added.
     466If sum of GPR index and VGPR register index beyond last available VGPR register or
     467this is not a VGPR register (SGPR or other), then operand register will be substituted by
     468V0 register.</p>
     469<p>The lowest 8 bits of M0 register holds the GPR index. The 12-15 bits holds GPR indexing mode.
     470The GPR indexing mode bits table:</p>
     471<table>
     472<thead>
     473<tr>
     474<th>Bit</th>
     475<th>Description</th>
     476</tr>
     477</thead>
     478<tbody>
     479<tr>
     480<td>0</td>
     481<td>Apply GPR indexing to VSRC0 operand</td>
     482</tr>
     483<tr>
     484<td>1</td>
     485<td>Apply GPR indexing to VSRC1 operand</td>
     486</tr>
     487<tr>
     488<td>2</td>
     489<td>Apply GPR indexing to VSRC2 operand</td>
     490</tr>
     491<tr>
     492<td>3</td>
     493<td>Apply GPR indexing to VDST operand</td>
     494</tr>
     495</tbody>
     496</table>
    460497}}}