Implement shift opcodes

libevm/VM.cpp

@@ -536,6 +536,50 @@ void VM::interpretCases()
 			++m_pc;
 		CASE_END
 
+#ifdef EVM_USE_BITSHIFT
+		CASE_BEGIN(SHL)
+			ON_OP();
+			updateIOGas();
+
+			/// TODO: confirm shift >= 256 results in 0
+			*(m_sp - 1) = *m_sp << *(m_sp - 1);
+			--m_sp;
+			++m_pc;
+		CASE_END
+
+		CASE_BEGIN(SHR)
+			ON_OP();
+			updateIOGas();
+
+			/// TODO: confirm shift >= 256 results in 0
+			*(m_sp - 1) = *m_sp >> *(m_sp - 1);
+			--m_sp;
+			++m_pc;
+		CASE_END
+
+		CASE_BEGIN(SAR)
+		{
+			ON_OP();
+			updateIOGas();
+
+			s256 value = u2s(*m_sp);
+			u256 shift = *(m_sp - 1);
+			if (shift >= 256)
+			{
+				if (value >= 0)
+				    *(m_sp - 1) = 0;
+				else
+				    *(m_sp - 1) = s2u(-1);
+			}
+			else
+				*(m_sp - 1) = s2u(divWorkaround(value, exp256(2, shift)));
+
+			--m_sp;
+			++m_pc;
+		}
+		CASE_END
+#endif
+
 		CASE_BEGIN(BYTE)
 			ON_OP();
 			updateIOGas();