AMDGPU: Add some release 20 notes

[arsenm]

No description provided.

[llvmbot]

@llvm/pr-subscribers-backend-amdgpu

Author: Matt Arsenault (arsenm)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/128136.diff

1 Files Affected:

• (modified) llvm/docs/ReleaseNotes.md (+11)

diff --git a/llvm/docs/ReleaseNotes.md b/llvm/docs/ReleaseNotes.md
index c80aecfdea084..e654509792652 100644
--- a/llvm/docs/ReleaseNotes.md
+++ b/llvm/docs/ReleaseNotes.md
@@ -159,6 +159,17 @@ Changes to the AArch64 Backend
 Changes to the AMDGPU Backend
 -----------------------------
 
+* Initial support for gfx950
+
+* Improved ``llvm.memcpy``, ``llvm.memmove`` and ``llvm.memset`` lowering
+
+* Fixed expansion of 64-bit flat address space ``atomicrmw`` and
+  ``cmpxchg`` operations which may access private
+  memory. `noalias.addrspace` metadat may be used to avoid the
+  expansion if the target address is known to not be on the stack.
+
+* Fix compile failures when emitting unreachable functions.
+
 * Removed `llvm.amdgcn.flat.atomic.fadd` and
   `llvm.amdgcn.global.atomic.fadd` intrinsics. Users should use the
   {ref}`atomicrmw <i_atomicrmw>` instruction with `fadd` and

[github-actions]

@arsenm (or anyone else). If you would like to add a note about this fix in the release notes (completely optional). Please reply to this comment with a one or two sentence description of the fix. When you are done, please add the release:note label to this PR.