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BYTE reimplementation

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[Delivers #80911670]
This commit is contained in:
Paweł Bylica 2014-10-20 16:14:11 +02:00
parent afe02541ed
commit 607458b193
1 changed files with 6 additions and 15 deletions
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21
libevmjit/Compiler.cpp
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@ -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));