From bbcc3966445438e2d97e07d21491a83e9b0bbb99 Mon Sep 17 00:00:00 2001
From: florian <florian@freepascal.org>
Date: Mon, 21 Jun 2021 21:36:32 +0000
Subject: [PATCH]   * ARM: fix for Merge Add/Sub optimization

git-svn-id: trunk@49520 -
---
 compiler/arm/aoptcpu.pas | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/compiler/arm/aoptcpu.pas b/compiler/arm/aoptcpu.pas
index 233dbe5fd1..4a3ef1e596 100644
--- a/compiler/arm/aoptcpu.pas
+++ b/compiler/arm/aoptcpu.pas
@@ -640,6 +640,10 @@ Implementation
         into
 
         add/sub rx,ry,const1+/-const
+        or
+        mov rx,ry if const1+/-const=0
+        or
+        remove it, if rx=ry and const1+/-const=0
 
         check if the first operation has no postfix and condition
       }
@@ -664,7 +668,13 @@ Implementation
               Result:=true;
               if newvalue=0 then
                 begin
-                  RemoveCurrentP(p);
+                  if MatchOperand(taicpu(p).oper[0]^,taicpu(p).oper[1]^) then
+                    RemoveCurrentP(p)
+                  else
+                    begin
+                      taicpu(p).opcode:=A_MOV;
+                      taicpu(p).ops:=2;
+                    end;
                   Exit;
                 end;
             end;