From 1a6eef60e3aa265e0a5b70c632046883d3470a5d Mon Sep 17 00:00:00 2001
From: Yoichi Hirai <i@yoichihirai.com>
Date: Tue, 13 Sep 2016 19:34:33 +0200
Subject: [PATCH] Use inline assembly suggested by @chriseth

https://github.com/ethereum/solidity/pull/1091#discussion_r78606129
---
 libsolidity/codegen/ExpressionCompiler.cpp | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp
index abc82772aff9..bc5bb0887363 100644
--- a/libsolidity/codegen/ExpressionCompiler.cpp
+++ b/libsolidity/codegen/ExpressionCompiler.cpp
@@ -1340,14 +1340,13 @@ void ExpressionCompiler::appendArithmeticOperatorCode(Token::Value _operator, Ty
 		// Test for (minInt) / (-1)
 		if (c_isSigned && _operator == Token::Div)
 		{
-			m_context << Instruction::DUP1 // x
-				<< u256(2) << u256(255) << Instruction::EXP // 2 ** 255
-				<< Instruction::EQ;
-			// stack: (x == minInt), x, y
-			m_context << Instruction::DUP3 << Instruction::NOT // ~y
-				<< Instruction::ISZERO;
-			// stack: (y == (-1)), (x == minInt), x, y
-			m_context << Instruction::AND;
+			m_context.appendInlineAssembly(R"(
+				and(
+					eq(x, exp(2, 255)), // x == 2**256 (min int)
+					iszero(not(y)) // y == -1
+				)
+			)",
+			{"y", "x"});
 			m_context.appendConditionalJumpTo(m_context.errorTag());
 		}