[llvm] AMDGPU/Docs: Memory model updates for GFX940, GFX941, GFX942 (PR #71091)
Konstantin Zhuravlyov via llvm-commits
llvm-commits at lists.llvm.org
Thu Nov 2 11:40:11 PDT 2023
https://github.com/kzhuravl created https://github.com/llvm/llvm-project/pull/71091
- Update memory model sequences for GFX940, GFX941, GFX942 to match implementation
- Re-title "Memory Model GFX940" to "Memory Model GFX942"
Co-authored with @t-tye
Change-Id: I82f1707b7c3e010ce1fe8207fcca18c4570057a3
>From 75f002f7ab11b7c8fce9920938fadfe02e9003b0 Mon Sep 17 00:00:00 2001
From: Konstantin Zhuravlyov <kzhuravl at amd.com>
Date: Thu, 2 Nov 2023 10:18:11 -0400
Subject: [PATCH] AMDGPU/Docs: Memory model updates for GFX940, GFX941, GFX942
- Update memory model sequences for GFX940, GFX941, GFX942
to match implementation
- Re-title "Memory Model GFX940" to "Memory Model GFX942"
Co-authored with @t-tye
Change-Id: I82f1707b7c3e010ce1fe8207fcca18c4570057a3
---
llvm/docs/AMDGPUUsage.rst | 58 +++++++++++++++++++++++++++------------
1 file changed, 40 insertions(+), 18 deletions(-)
diff --git a/llvm/docs/AMDGPUUsage.rst b/llvm/docs/AMDGPUUsage.rst
index 4f616482545867c..88d7479b964084c 100644
--- a/llvm/docs/AMDGPUUsage.rst
+++ b/llvm/docs/AMDGPUUsage.rst
@@ -5538,7 +5538,7 @@ following sections:
* :ref:`amdgpu-amdhsa-memory-model-gfx6-gfx9`
* :ref:`amdgpu-amdhsa-memory-model-gfx90a`
-* :ref:`amdgpu-amdhsa-memory-model-gfx940`
+* :ref:`amdgpu-amdhsa-memory-model-gfx942`
* :ref:`amdgpu-amdhsa-memory-model-gfx10-gfx11`
.. _amdgpu-amdhsa-memory-model-gfx6-gfx9:
@@ -9190,12 +9190,12 @@ in table :ref:`amdgpu-amdhsa-memory-model-code-sequences-gfx90a-table`.
- system for OpenCL.*
============ ============ ============== ========== ================================
-.. _amdgpu-amdhsa-memory-model-gfx940:
+.. _amdgpu-amdhsa-memory-model-gfx942:
-Memory Model GFX940
+Memory Model GFX942
+++++++++++++++++++
-For GFX940:
+For GFX942:
* Each agent has multiple shader arrays (SA).
* Each SA has multiple compute units (CU).
@@ -9249,7 +9249,7 @@ For GFX940:
model. See :ref:`amdgpu-amdhsa-memory-spaces`.
* The vector and scalar memory operations use an L2 cache.
- * The gfx940 can be configured as a number of smaller agents with each having
+ * The gfx942 can be configured as a number of smaller agents with each having
a single L2 shared by all CUs on the same agent, or as fewer (possibly one)
larger agents with groups of CUs on each agent each sharing separate L2
caches.
@@ -9325,15 +9325,15 @@ only accessed by a single thread, and is always write-before-read, there is
never a need to invalidate these entries from the L1 cache. Hence all cache
invalidates are done as ``*_vol`` to only invalidate the volatile cache lines.
-The code sequences used to implement the memory model for GFX940 are defined
-in table :ref:`amdgpu-amdhsa-memory-model-code-sequences-gfx940-table`.
+The code sequences used to implement the memory model for GFX940, GFX941, GFX942
+are defined in table :ref:`amdgpu-amdhsa-memory-model-code-sequences-gfx940-gfx941-gfx942-table`.
- .. table:: AMDHSA Memory Model Code Sequences GFX940
- :name: amdgpu-amdhsa-memory-model-code-sequences-gfx940-table
+ .. table:: AMDHSA Memory Model Code Sequences GFX940, GFX941, GFX942
+ :name: amdgpu-amdhsa-memory-model-code-sequences-gfx940-gfx941-gfx942-table
============ ============ ============== ========== ================================
LLVM Instr LLVM Memory LLVM Memory AMDGPU AMDGPU Machine Code
- Ordering Sync Scope Address GFX940
+ Ordering Sync Scope Address GFX940, GFX941, GFX942
Space
============ ============ ============== ========== ================================
**Non-Atomic**
@@ -9368,12 +9368,20 @@ in table :ref:`amdgpu-amdhsa-memory-model-code-sequences-gfx940-table`.
load *none* *none* - local 1. ds_load
store *none* *none* - global - !volatile & !nontemporal
- generic
- - private 1. buffer/global/flat_store
- - constant
+ - private 1. GFX940, GFX941
+ - constant buffer/global/flat_store
+ sc0=1 sc1=1
+ GFX942
+ buffer/global/flat_store
+
- !volatile & nontemporal
- 1. buffer/global/flat_store
- nt=1
+ 1. GFX940, GFX941
+ buffer/global/flat_store
+ nt=1 sc0=1 sc1=1
+ GFX942
+ buffer/global/flat_store
+ nt=1
- volatile
@@ -10065,8 +10073,12 @@ in table :ref:`amdgpu-amdhsa-memory-model-code-sequences-gfx940-table`.
**Release Atomic**
------------------------------------------------------------------------------------
- store atomic release - singlethread - global 1. buffer/global/flat_store
- - wavefront - generic
+ store atomic release - singlethread - global 1. GFX940, GFX941
+ - wavefront - generic buffer/global/flat_store
+ sc0=1 sc1=1
+ GFX942
+ buffer/global/flat_store
+
store atomic release - singlethread - local *If TgSplit execution mode,
- wavefront local address space cannot
be used.*
@@ -10103,7 +10115,12 @@ in table :ref:`amdgpu-amdhsa-memory-model-code-sequences-gfx940-table`.
store that is being
released.
- 2. buffer/global/flat_store sc0=1
+ 2. GFX940, GFX941
+ buffer/global/flat_store
+ sc0=1 sc1=1
+ GFX942
+ buffer/global/flat_store
+ sc0=1
store atomic release - workgroup - local *If TgSplit execution mode,
local address space cannot
be used.*
@@ -10162,7 +10179,12 @@ in table :ref:`amdgpu-amdhsa-memory-model-code-sequences-gfx940-table`.
store that is being
released.
- 3. buffer/global/flat_store sc1=1
+ 3. GFX940, GFX941
+ buffer/global/flat_store
+ sc0=1 sc1=1
+ GFX942
+ buffer/global/flat_store
+ sc1=1
store atomic release - system - global 1. buffer_wbl2 sc0=1 sc1=1
- generic
- Must happen before
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