From b13f1ac2aa05e5778deb5dbea210d3d6f725acb3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20Bylica?= <pawel.bylica@imapp.pl>
Date: Mon, 20 Oct 2014 16:08:15 +0200
Subject: [PATCH 1/3] Check if pushed item is a word

---
 libevmjit/BasicBlock.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libevmjit/BasicBlock.cpp b/libevmjit/BasicBlock.cpp
index 02c85165d..736e0a572 100644
--- a/libevmjit/BasicBlock.cpp
+++ b/libevmjit/BasicBlock.cpp
@@ -32,6 +32,7 @@ BasicBlock::BasicBlock(std::string _name, llvm::Function* _mainFunc) :
 
 void BasicBlock::Stack::push(llvm::Value* _value)
 {
+	assert(_value->getType() == Type::i256);
 	m_backend.push_back(_value);
 }
 

From afe02541ed57b0a2ba8700cd60934b059fa916ef Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20Bylica?= <pawel.bylica@imapp.pl>
Date: Mon, 20 Oct 2014 16:08:59 +0200
Subject: [PATCH 2/3] Endianness handler

---
 libevmjit/Endianness.cpp | 24 ++++++++++++++++++++++++
 libevmjit/Endianness.h   | 22 ++++++++++++++++++++++
 2 files changed, 46 insertions(+)
 create mode 100644 libevmjit/Endianness.cpp
 create mode 100644 libevmjit/Endianness.h

diff --git a/libevmjit/Endianness.cpp b/libevmjit/Endianness.cpp
new file mode 100644
index 000000000..7de7b9514
--- /dev/null
+++ b/libevmjit/Endianness.cpp
@@ -0,0 +1,24 @@
+
+#include "Endianness.h"
+
+#include <llvm/IR/IntrinsicInst.h>
+
+#include "Type.h"
+
+namespace dev
+{
+namespace eth
+{
+namespace jit
+{
+
+llvm::Value* Endianness::toBE(llvm::IRBuilder<>& _builder, llvm::Value* _word)
+{
+	// TODO: Native is Little Endian
+	auto bswap = llvm::Intrinsic::getDeclaration(_builder.GetInsertBlock()->getParent()->getParent(), llvm::Intrinsic::bswap, Type::i256);
+	return _builder.CreateCall(bswap, _word);
+}
+
+}
+}
+}
diff --git a/libevmjit/Endianness.h b/libevmjit/Endianness.h
new file mode 100644
index 000000000..7b449b4d8
--- /dev/null
+++ b/libevmjit/Endianness.h
@@ -0,0 +1,22 @@
+
+#pragma once
+
+#include <llvm/IR/IRBuilder.h>
+
+namespace dev
+{
+namespace eth
+{
+namespace jit
+{
+
+class Endianness
+{
+public:
+
+	static llvm::Value* toBE(llvm::IRBuilder<>& _builder, llvm::Value* _word);
+};
+
+}
+}
+}

From 607458b1936143870e9fc2c00837d5cae2a019fa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20Bylica?= <pawel.bylica@imapp.pl>
Date: Mon, 20 Oct 2014 16:14:11 +0200
Subject: [PATCH 3/3] BYTE reimplementation

[Delivers #80911670]
---
 libevmjit/Compiler.cpp | 21 ++++++---------------
 1 file changed, 6 insertions(+), 15 deletions(-)

diff --git a/libevmjit/Compiler.cpp b/libevmjit/Compiler.cpp
index 63ba83a77..76daca792 100644
--- a/libevmjit/Compiler.cpp
+++ b/libevmjit/Compiler.cpp
@@ -15,6 +15,7 @@
 #include "Ext.h"
 #include "GasMeter.h"
 #include "Utils.h"
+#include "Endianness.h"
 
 namespace dev
 {
@@ -420,21 +421,11 @@ void Compiler::compileBasicBlock(BasicBlock& basicBlock, bytesConstRef bytecode,
 			const auto byteNum = stack.pop();
 			auto value = stack.pop();
 
-			/*
-			if (byteNum < 32)	- use select
-			{
-			value <<= byteNum*8
-			value >>= 31*8
-			push value
-			}
-			else push 0
-			*/
-
-			// TODO: Shifting by 0 gives wrong results as of this bug http://llvm.org/bugs/show_bug.cgi?id=16439
-
-			auto shbits = m_builder.CreateShl(byteNum, Constant::get(3));
-			value = m_builder.CreateShl(value, shbits);
-			value = m_builder.CreateLShr(value, Constant::get(31 * 8));
+			//
+			value = Endianness::toBE(m_builder, value);
+			auto bytes = m_builder.CreateBitCast(value, llvm::VectorType::get(Type::Byte, 32), "bytes");
+			auto byte = m_builder.CreateExtractElement(bytes, byteNum, "byte");
+			value = m_builder.CreateZExt(byte, Type::i256);
 
 			auto byteNumValid = m_builder.CreateICmpULT(byteNum, Constant::get(32));
 			value = m_builder.CreateSelect(byteNumValid, value, Constant::get(0));