From f41025f5dd7d1b7fb4367f0aceac021a7a1f8478 Mon Sep 17 00:00:00 2001
From: florian <florian@freepascal.org>
Date: Wed, 6 Mar 2024 22:56:06 +0100
Subject: [PATCH]   * optimize also -(x+1) and -(1+x) into not(x)

---
 compiler/nmat.pas   | 14 ++++++++++++++
 tests/tbs/tb0711.pp |  6 ++++++
 2 files changed, 20 insertions(+)

diff --git a/compiler/nmat.pas b/compiler/nmat.pas
index 39ba5c1424..69ce0548c0 100644
--- a/compiler/nmat.pas
+++ b/compiler/nmat.pas
@@ -1092,6 +1092,20 @@ implementation
                 result:=tunarynode(left).left.getcopy;
                 exit;
               end;
+          end
+        { transform -(x+1) or -(1+x) into not(x) }
+        else if is_integer(left.resultdef) and is_signed(left.resultdef) and (left.nodetype=addn) and ((localswitches*[cs_check_overflow,cs_check_range])=[]) then
+          begin
+            if is_constintnode(taddnode(left).right) and (tordconstnode(taddnode(left).right).value=1) then
+              begin
+                result:=cnotnode.create(taddnode(left).left.getcopy);
+                exit;
+              end
+            else if is_constintnode(taddnode(left).left) and (tordconstnode(taddnode(left).left).value=1) then
+              begin
+                result:=cnotnode.create(taddnode(left).right.getcopy);
+                exit;
+              end;
           end;
       end;
 
diff --git a/tests/tbs/tb0711.pp b/tests/tbs/tb0711.pp
index f9d8173bfa..4233d6480a 100644
--- a/tests/tbs/tb0711.pp
+++ b/tests/tbs/tb0711.pp
@@ -6,4 +6,10 @@ begin
 
   if -l-1<>-1235 then
     halt(1);
+
+  if -(l+1)<>-1235 then
+    halt(2);
+
+  if -(1+l)<>-1235 then
+    halt(2);
 end.
\ No newline at end of file