From 1008c70a14c2ad6a6ec70e9233914daa63c8a95d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20Bylica?= <pawel.bylica@imapp.pl>
Date: Thu, 30 Oct 2014 19:17:55 +0100
Subject: [PATCH] Create dedicated function for pushdata reading

---
 libevmjit/Utils.cpp | 17 +++++++++++++++++
 libevmjit/Utils.h   |  6 ++++++
 2 files changed, 23 insertions(+)

diff --git a/libevmjit/Utils.cpp b/libevmjit/Utils.cpp
index 0fd9c0e41..966dc69bd 100644
--- a/libevmjit/Utils.cpp
+++ b/libevmjit/Utils.cpp
@@ -35,6 +35,23 @@ i256 eth2llvm(u256 _u)
 	return i;
 }
 
+u256 readPushData(const byte*& _curr, const byte* _end)
+{
+	auto pushInst = *_curr;
+	assert(Instruction(pushInst) >= Instruction::PUSH1 && Instruction(pushInst) <= Instruction::PUSH32);
+	auto numBytes = pushInst - static_cast<size_t>(Instruction::PUSH1) + 1;
+	u256 value;
+	++_curr;	// Point the data
+	for (decltype(numBytes) i = 0; i < numBytes; ++i)
+	{
+		byte b = (_curr != _end) ? *_curr++ : 0;
+		value <<= 8;
+		value |= b;
+	}
+	--_curr;	// Point the last real byte read
+	return value;
+}
+
 }
 }
 }
diff --git a/libevmjit/Utils.h b/libevmjit/Utils.h
index 7a3afda64..9fa9f050e 100644
--- a/libevmjit/Utils.h
+++ b/libevmjit/Utils.h
@@ -5,6 +5,7 @@
 
 #include <libdevcore/Common.h>
 #include <libdevcore/Log.h>
+#include <libevmface/Instruction.h>
 
 namespace dev
 {
@@ -29,6 +30,11 @@ static_assert(sizeof(i256) == 32, "Wrong i265 size");
 u256 llvm2eth(i256);
 i256 eth2llvm(u256);
 
+/// Reads PUSH data from pointed fragment of bytecode and constructs number out of it
+/// Reading out of bytecode means reading 0
+/// @param _curr is updates and points the last real byte read
+u256 readPushData(const byte*& _curr, const byte* _end);
+
 #define ANY_PUSH	  PUSH1:  \
 	case Instruction::PUSH2:  \
 	case Instruction::PUSH3:  \