From 68986a58b6df442b1204558a85ca4b29f61c50a0 Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Fri, 13 Sep 2019 18:09:09 +0200
Subject: [PATCH 1/2] Test.

---
 .../side_effects_in_for_condition.yul               | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 test/libyul/yulOptimizerTests/expressionSimplifier/side_effects_in_for_condition.yul

diff --git a/test/libyul/yulOptimizerTests/expressionSimplifier/side_effects_in_for_condition.yul b/test/libyul/yulOptimizerTests/expressionSimplifier/side_effects_in_for_condition.yul
new file mode 100644
index 000000000..7e181a097
--- /dev/null
+++ b/test/libyul/yulOptimizerTests/expressionSimplifier/side_effects_in_for_condition.yul
@@ -0,0 +1,13 @@
+{
+  for {} div(create(0, 1, 0), shl(msize(), 1)) {}
+  {
+  }
+}
+// ====
+// step: expressionSimplifier
+// EVMVersion: >byzantium
+// ----
+// {
+//     for { } div(create(0, 1, 0), shl(msize(), 1)) { }
+//     { }
+// }

From c224b09bb35c67fe2abadfb2f0f40b6fd2078e84 Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Fri, 13 Sep 2019 18:09:16 +0200
Subject: [PATCH 2/2] Fix reordering bug in optimizer.

---
 Changelog.md         | 1 +
 libevmasm/RuleList.h | 6 ++++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/Changelog.md b/Changelog.md
index 976ee721a..519e11559 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -14,6 +14,7 @@ Compiler Features:
 
 Bugfixes:
  * Fix internal error when popping a dynamic storage array of mappings.
+ * Yul Optimizer: Fix reordering bug in connection with shifted one and mul/div-instructions in for loop conditions.
 
 
 ### 0.5.11 (2019-08-12)
diff --git a/libevmasm/RuleList.h b/libevmasm/RuleList.h
index f2422ce58..58e773f30 100644
--- a/libevmasm/RuleList.h
+++ b/libevmasm/RuleList.h
@@ -475,7 +475,8 @@ std::vector<SimplificationRule<Pattern>> simplificationRuleListPart7(
 		[=]() -> Pattern {
 			return {Instruction::SHL, {Y, X}};
 		},
-		false
+		// Actually only changes the order, does not remove.
+		true
 	});
 	rules.push_back({
 		// MUL(SHL(X, 1), Y) -> SHL(X, Y)
@@ -492,7 +493,8 @@ std::vector<SimplificationRule<Pattern>> simplificationRuleListPart7(
 		[=]() -> Pattern {
 			return {Instruction::SHR, {Y, X}};
 		},
-		false
+		// Actually only changes the order, does not remove.
+		true
 	});
 
 	std::function<bool()> feasibilityFunction = [=]() {