[gcc(refs/users/meissner/heads/work122)] Update ChangeLog.meissner

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

https://gcc.gnu.org/g:fb5a0e51cc9f435071cf46090bd8dd0aa99b895a

commit fb5a0e51cc9f435071cf46090bd8dd0aa99b895a
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Thu Jun 8 12:54:54 2023 -0400

    Update ChangeLog.meissner

Diff:
---
 gcc/ChangeLog.meissner | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/gcc/ChangeLog.meissner b/gcc/ChangeLog.meissner
index 1c40084ce43..63644d60a12 100644
--- a/gcc/ChangeLog.meissner
+++ b/gcc/ChangeLog.meissner
@@ -1,4 +1,4 @@
-==================== Branch work122, patch #1 ====================
+==================== Branch work122, patch #2 ====================
 
 Fix power10 fusion and -fstack-protector, PR target/105325
 
@@ -6,10 +6,12 @@ This patch fixes an issue where if you use the -fstack-protector and
 -mcpu=power10 options and you have a large stack frame, the GCC compiler will
 generate a LWA instruction with a large offset.
 
-There are several problems:
+There are several problems with the current GCC:
 
     1)	The prefixed attribute was not checking insns with the type
-	fused_load_cmpi for being load insns.
+	fused_load_cmpi for being load insns.  This meant if the load + compare
+	fusion was not split, it would not know that the load should be
+	prefixed.
 
     2)	The recognition of LWA for being prefixed looks at the "sign_extend"
 	attribute and whether the register mode was different than the memory
@@ -18,7 +20,7 @@ There are several problems:
     3)	The constraints in fusion.md (generated by genfusion.pl) use "m" for LWA
 	and LD, when they should use "YZ".
 
-    4)	There is a lwa_operand that should be used instead of
+    4)	There is a lwa_operand predicate that should be used instead of
 	ds_form_mem_operand for the LWA instruction.
 
 The main fix is to modify genfusion.pl that it sets the appropriate predicates
@@ -33,15 +35,15 @@ I set the "sign_extend" attribute on the cases that generate LWA.
 
 I modified the "prefixed" attribute so that it also checks fused_load_cmpi.
 
-2023-06-06   Michael Meissner  <meissner@linux.ibm.com>
+2023-06-07   Michael Meissner  <meissner@linux.ibm.com>
 
 gcc/
 
 	* config/rs6000/genfusion.pl (gen_ld_cmpi_p10_one): Fix constraints and
 	predicates for LD and LWA.  Optimize LWA/CMPDI to generate LWZ/CMPWI if
-	we don't need the result of the load after the comparison.  Change the
-	name of the insn pattern to reflect whether a DImode or SImode register
-	is loaded.  Set sign_extend attribute for LWA instruction.
+	we don't need the result of the load after the comparison.  Set the
+	sign_extend attribute for LWA instruction.  For LWA where we do not need
+	the result of the load after the comparison, use LWZ and CMPWI.
 	* config/rs6000/fusion.md: Regenerate.
 	* config/rs6000/rs6000.md (prefixed attribute): Treat fused_load_cmpi
 	insns as being load insns.
@@ -52,6 +54,8 @@ gcc/testsuite/
 	* gcc.target/powerpc/fusion-p10-ldcmpi.c: Adjust names and insn counts
 	for PR target/105325 fix.
 
+==================== Branch work122, patch #1 was reverted ====================
+
 ==================== Branch work122, baseline ====================
 
 2023-06-06   Michael Meissner  <meissner@linux.ibm.com>