From 86ef76953fdddfcb1ba18a703d78c83df1641095 Mon Sep 17 00:00:00 2001
From: Christian Krause <me@ckrause.org>
Date: Fri, 13 Sep 2024 22:05:31 +0200
Subject: [PATCH] fix optimizer bug

---
 CHANGELOG.md             |  4 ++++
 src/eval/optimizer.cpp   |  5 -----
 tests/optimizer/E047.asm |  4 +++-
 tests/optimizer/E049.asm | 10 ++++++++++
 4 files changed, 17 insertions(+), 6 deletions(-)
 create mode 100644 tests/optimizer/E049.asm

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 794ac394..49af0f86 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@ To install or update LODA, please follow the [installation instructions](https:/
 
 ## [Unreleased]
 
+### Bugfixes
+
+* Fix optimizer bug
+
 ## v24.9.7
 
 ### Bugfixes
diff --git a/src/eval/optimizer.cpp b/src/eval/optimizer.cpp
index 5651d41d..768f54a7 100644
--- a/src/eval/optimizer.cpp
+++ b/src/eval/optimizer.cpp
@@ -793,11 +793,6 @@ bool Optimizer::collapseMovLoops(Program &p) const {
     if (val < Number::ZERO) {
       p.ops.erase(p.ops.begin() + i, p.ops.begin() + i + 3);
       changed = true;
-    } else if (val == Number::ZERO) {
-      p.ops.erase(p.ops.begin() + i + 1, p.ops.begin() + i + 3);
-      p.ops[i] = Operation(Operation::Type::MOV, lpb.target,
-                           Operand(Operand::Type::CONSTANT, 0));
-      changed = true;
     } else {
       p.ops.erase(p.ops.begin() + i + 1, p.ops.begin() + i + 3);
       p.ops[i] = Operation(Operation::Type::MIN, lpb.target,
diff --git a/tests/optimizer/E047.asm b/tests/optimizer/E047.asm
index ce8cf89b..7278683a 100644
--- a/tests/optimizer/E047.asm
+++ b/tests/optimizer/E047.asm
@@ -5,4 +5,6 @@ lpb $0
 lpe
 add $0,7
 ; out
-mov $0,7
+add $0,3
+min $0,0
+add $0,7
diff --git a/tests/optimizer/E049.asm b/tests/optimizer/E049.asm
new file mode 100644
index 00000000..8709f033
--- /dev/null
+++ b/tests/optimizer/E049.asm
@@ -0,0 +1,10 @@
+; in
+sub $0,3
+lpb $0
+  mov $0,0
+lpe
+sub $0,7
+; out
+sub $0,3
+min $0,0
+sub $0,7