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

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

https://gcc.gnu.org/g:c2bb4e2b5131154648979c748d2029df2e457abb

commit c2bb4e2b5131154648979c748d2029df2e457abb
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Fri Jun 9 00:18:09 2023 -0400

    Update ChangeLog.meissner

Diff:
---
 gcc/ChangeLog.meissner | 35 ++++++++++-------------------------
 1 file changed, 10 insertions(+), 25 deletions(-)

diff --git a/gcc/ChangeLog.meissner b/gcc/ChangeLog.meissner
index 3bca12eb10e..055d3cd71b8 100644
--- a/gcc/ChangeLog.meissner
+++ b/gcc/ChangeLog.meissner
@@ -1,4 +1,4 @@
-==================== Branch work122, patch #2 ====================
+==================== Branch work122, patch #4 ====================
 
 Fix power10 fusion and -fstack-protector, PR target/105325
 
@@ -8,48 +8,33 @@ generate a LWA instruction with a large offset.
 
 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.  This meant if the load + compare
-	fusion was not split, the insn size might be off, and the wrong
-	instruction might be generated.
-
-    2)	The code in prefixed_load_p looks at the "sign_extend" attribute and
-	whether the register mode was different than the memory for SImode loads
-	to detect LWA instructions.
-
-    3)	The constraints in fusion.md (generated by genfusion.pl) use "m" for LWA
+    1)	The constraints in fusion.md (generated by genfusion.pl) use "m" for LWA
 	and LD, when they should use "YZ".
 
-    4)	The code to determine whether to split the insn if it has a prefixed
-	address was passing in SImode.  For LWA, we need to pass in DImode and
-	not SImode to properly determine if the address is prefixed.
+    2)	The normal calls to address_is_non_pfx_d_or_x doesn't work with lwa,
+	because you need to pass in DImode instead of SImode.  It is simplified
+	if you use the lwa_operand predicate instead of ds_form_mem_operand.
 
 The fix is to modify genfusion.pl that it sets the "YZ" constraint instead of
 "m" for the ld and lwa instructions.
 
-I also set the signed attribute on the HI/SImode loads that do sign extension.
-
-I modified the predicate for lwa to use lwa_operand instead of the predicate
-ds_form_mem_operand.  This predicate has direct checks to prevent a prefixed lwa
-from being generated.  I also modified the condition for the insn splitter so
-that it passes DImode for the lwa instructions and not SImode.
+I modified the genfusion.pl code use to use lwa_operand for the lwa instruction
+to prevent prefixed addresses at combine time.
 
-I modified the "prefixed" attribute so that it also checks fused_load_cmpi.
-
-2023-06-07   Michael Meissner  <meissner@linux.ibm.com>
+2023-06-08   Michael Meissner  <meissner@linux.ibm.com>
 
 gcc/
 
 	* config/rs6000/genfusion.pl (gen_ld_cmpi_p10_one): Fix problems that
 	allowed prefixed lwa to be generated.
 	* config/rs6000/fusion.md: Regenerate.
-	* config/rs6000/rs6000.md (prefixed attribute): Treat fused_load_cmpi
-	insns as being load insns.
 
 gcc/testsuite/
 
 	* g++.target/powerpc/pr105325.C: New test.
 
+==================== Branch work122, patch #3 was reverted ====================
+
 ==================== Branch work122, patch #2 was reverted ====================
 
 ==================== Branch work122, patch #1 was reverted ====================