[llvm] [RISCV] Add a release note about tail folding being enabled. NFC (PR #153535)

[Luke Lau via llvm-commits]

https://github.com/lukel97 updated https://github.com/llvm/llvm-project/pull/153535

>From 6b13fccda2f9444a1fa7596564ccc845130ad975 Mon Sep 17 00:00:00 2001
From: Luke Lau <luke at igalia.com>
Date: Thu, 14 Aug 2025 13:41:35 +0800
Subject: [PATCH 1/2] [RISCV] Add a release note about tail folding being
 enabled. NFC

It's probably useful for users to know how to get the old scalar epilogue back if they need it.
---
 llvm/docs/ReleaseNotes.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/llvm/docs/ReleaseNotes.md b/llvm/docs/ReleaseNotes.md
index 88b7e6d6585f7..f3ef70a01375c 100644
--- a/llvm/docs/ReleaseNotes.md
+++ b/llvm/docs/ReleaseNotes.md
@@ -109,6 +109,9 @@ Changes to the PowerPC Backend
 Changes to the RISC-V Backend
 -----------------------------
 
+* The loop vectorizer now performs tail folding by default on RISC-V, which
+  removes the need for a scalar epilogue loop. To restore the previous behaviour
+  use `-mllvm -prefer-predicate-over-epilogue=scalar-epilogue`.
 * `llvm-objdump` now has basic support for switching between disassembling code
   and data using mapping symbols such as `$x` and `$d`. Switching architectures
   using `$x` with an architecture string suffix is not yet supported.

>From b2d5bce19d490514384d0622ad19d6c1a69678b9 Mon Sep 17 00:00:00 2001
From: Luke Lau <luke at igalia.com>
Date: Fri, 15 Aug 2025 11:50:41 +0800
Subject: [PATCH 2/2] Drop -mllvm from the flag

Hopefully users can figure out they need to pass -mllvm on Clang
---
 llvm/docs/ReleaseNotes.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/docs/ReleaseNotes.md b/llvm/docs/ReleaseNotes.md
index f3ef70a01375c..01efeae63c499 100644
--- a/llvm/docs/ReleaseNotes.md
+++ b/llvm/docs/ReleaseNotes.md
@@ -111,7 +111,7 @@ Changes to the RISC-V Backend
 
 * The loop vectorizer now performs tail folding by default on RISC-V, which
   removes the need for a scalar epilogue loop. To restore the previous behaviour
-  use `-mllvm -prefer-predicate-over-epilogue=scalar-epilogue`.
+  use `-prefer-predicate-over-epilogue=scalar-epilogue`.
 * `llvm-objdump` now has basic support for switching between disassembling code
   and data using mapping symbols such as `$x` and `$d`. Switching architectures
   using `$x` with an architecture string suffix is not yet supported.