From 5b4b4011c7c122820603cec7306cd2f4774ecbce Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Wed, 4 Sep 2019 13:20:56 +0200
Subject: [PATCH] Extend memory beyond 32 byte addresses in interpreter.

---
 .../access_large_memory_offsets.yul                | 14 ++++++++++++++
 .../yulInterpreter/EVMInstructionInterpreter.cpp   | 13 ++++++-------
 2 files changed, 20 insertions(+), 7 deletions(-)
 create mode 100644 test/libyul/yulInterpreterTests/access_large_memory_offsets.yul

diff --git a/test/libyul/yulInterpreterTests/access_large_memory_offsets.yul b/test/libyul/yulInterpreterTests/access_large_memory_offsets.yul
new file mode 100644
index 000000000..483220bc1
--- /dev/null
+++ b/test/libyul/yulInterpreterTests/access_large_memory_offsets.yul
@@ -0,0 +1,14 @@
+{
+    mstore(0, 7)
+    sstore(0, mload(0))
+    mstore(sub(0, 1), sub(0, 1))
+    sstore(1, mload(sub(0, 1)))
+}
+// ----
+// Trace:
+// Memory dump:
+//      0: ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff07
+//   FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFE0: 00000000000000000000000000000000000000000000000000000000000000ff
+// Storage dump:
+//   0000000000000000000000000000000000000000000000000000000000000000: 0000000000000000000000000000000000000000000000000000000000000007
+//   0000000000000000000000000000000000000000000000000000000000000001: ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
diff --git a/test/tools/yulInterpreter/EVMInstructionInterpreter.cpp b/test/tools/yulInterpreter/EVMInstructionInterpreter.cpp
index 70e163bf4..45584a19f 100644
--- a/test/tools/yulInterpreter/EVMInstructionInterpreter.cpp
+++ b/test/tools/yulInterpreter/EVMInstructionInterpreter.cpp
@@ -248,16 +248,15 @@ u256 EVMInstructionInterpreter::eval(
 		return m_state.gaslimit;
 	// --------------- memory / storage / logs ---------------
 	case Instruction::MLOAD:
-		if (accessMemory(arg[0], 0x20))
-			return readMemoryWord(arg[0]);
-		return 0;
+		accessMemory(arg[0], 0x20);
+		return readMemoryWord(arg[0]);
 	case Instruction::MSTORE:
-		if (accessMemory(arg[0], 0x20))
-			writeMemoryWord(arg[0], arg[1]);
+		accessMemory(arg[0], 0x20);
+		writeMemoryWord(arg[0], arg[1]);
 		return 0;
 	case Instruction::MSTORE8:
-		if (accessMemory(arg[0], 1))
-			m_state.memory[arg[0]] = uint8_t(arg[1] & 0xff);
+		accessMemory(arg[0], 1);
+		m_state.memory[arg[0]] = uint8_t(arg[1] & 0xff);
 		return 0;
 	case Instruction::SLOAD:
 		return m_state.storage[h256(arg[0])];