[llvm] [AMDGPU] Update AMDGPUUsage.rst to document two intrinsics (PR #123816)

[Jun Wang via llvm-commits]

https://github.com/jwanggit86 created https://github.com/llvm/llvm-project/pull/123816

The AMDGPUUsage.rst file is updated to document tow intrinsics: llvm.amdgcn.move.dpp and llvm.amdgcn.update.dpp.

>From 77b26395989269ef10807ec5d85ad97e9f79f75d Mon Sep 17 00:00:00 2001
From: Jun Wang <jwang86 at yahoo.com>
Date: Tue, 21 Jan 2025 12:48:49 -0800
Subject: [PATCH] [AMDGPU] Update AMDGPUUsage.rst to document two intrinsics

The AMDGPUUsage.rst file is updated to document tow intrinsics:
llvm.amdgcn.move.dpp and llvm.amdgcn.update.dpp.
---
 llvm/docs/AMDGPUUsage.rst | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/llvm/docs/AMDGPUUsage.rst b/llvm/docs/AMDGPUUsage.rst
index 40b393224f15dd..132a7444805620 100644
--- a/llvm/docs/AMDGPUUsage.rst
+++ b/llvm/docs/AMDGPUUsage.rst
@@ -1422,6 +1422,18 @@ The AMDGPU backend implements the following LLVM IR intrinsics.
                                                    Returns a pair for the swapped registers. The first element of the return
                                                    corresponds to the swapped element of the first argument.
 
+  llvm.amdgcn.mov.dpp                              The llvm.amdgcn.mov.dpp.i32 intrinsic represents the mov.dpp operation in AMDGPU.
+                                                   This operation is being deprecated and can be replaced with llvm.amdgcn.update.dpp.
+
+  llvm.amdgcn.update.dpp                           The llvm.amdgcn.update.dpp intrinsic represents the update.dpp operation in AMDGPU.
+                                                   It takes an old value, a source operand, a DPP control operand, a row mask, a bank mask, and a bound control.
+                                                   This operation is equivalent to a sequence of v_mov_b32 operations.
+                                                   It is preferred over llvm.amdgcn.mov.dpp.i32 for future use.
+                                                   `llvm.amdgcn.update.dpp.i32 <old> <src> <dpp_ctrl> <row_mask> <bank_mask> <bound_ctrl>`
+                                                   Should be equivalent to:
+                                                   - `v_mov_b32 <dest> <old>`
+                                                   - `v_mov_b32 <dest> <src> <dpp_ctrl> <row_mask> <bank_mask> <bound_ctrl>`
+
   ==============================================   ==========================================================
 
 .. TODO::