[gcc(refs/users/meissner/heads/work089)] Update ChangeLog.meissner.

[Michael Meissner <meissner@gcc.gnu.org>]

https://gcc.gnu.org/g:27908e2efc13f7b8e47c02f0413d57d167c98d2f

commit 27908e2efc13f7b8e47c02f0413d57d167c98d2f
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Thu May 12 18:30:59 2022 -0400

    Update ChangeLog.meissner.
    
    2022-05-12   Michael Meissner  <meissner@linux.ibm.com>
    
    gcc/
            * ChangeLog.meissner: Update.

Diff:
---
 gcc/ChangeLog.meissner | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/gcc/ChangeLog.meissner b/gcc/ChangeLog.meissner
index f4f767e8e14..0e1adbcaee4 100644
--- a/gcc/ChangeLog.meissner
+++ b/gcc/ChangeLog.meissner
@@ -1,3 +1,22 @@
+==================== work089 patch #4
+
+Delay splitting addti3/subti3 until first split pass.
+
+This patch makes addti3 and subti3 be define_insn_and_split instead of
+define_expand.  This patch will be a building block to support in a future
+patch PR target/103109 which wants to optimize 128-bit some integer
+multiply-add combinations to use the power9 maddld, maddhd, maddhdu
+instructions.  In order to support recognizing the multiply and add
+combination, we need to keep the addti3 and subti3 as complete insns
+through the combiner phase.
+
+2022-05-12   Michael Meissner  <meissner@linux.ibm.com>
+
+gcc/
+	* config/rs6000/rs6000.md (addti3): Don't immediately expand the
+	insn.  Delay expansion until the split passes.
+	(subti3): Likewise.
+
 ==================== work089 patch #3
 
 Replace UNSPEC with RTL code for extendditi2.