diff --git a/src/simulator/machine.rs b/src/simulator/machine.rs
index fdb9b0f..d1fcd3a 100644
--- a/src/simulator/machine.rs
+++ b/src/simulator/machine.rs
@@ -385,24 +385,24 @@ impl Machine {
 
 	/// Executes RISC-V Integer Register-Immediate Instructions on the machine
 	fn opi_instruction(&mut self, inst: Instruction) -> Result<(), MachineError> {
-		let mut compute = |operation: &dyn Fn (i64, i64) -> i64| {
-			self.int_reg.set_reg(inst.rd, operation(self.int_reg.get_reg(inst.rs1), inst.imm12_I_signed as i64));
+		let rs1 = self.int_reg.get_reg(inst.rs1);
+		let imm12 = inst.imm12_I_signed as i64;
+		let shamt = inst.shamt as i64;
+		let mut compute = |operation: &dyn Fn (i64, i64) -> i64, a, b| {
+			self.int_reg.set_reg(inst.rd, operation(a, b));
 			Ok(())
 		};
 		match inst.funct3 {
-			RISCV_OPI_ADDI =>	compute(&std::ops::Add::add),
-			RISCV_OPI_SLTI =>	compute(&|a, b| { (a < b) as i64 }),
-			RISCV_OPI_XORI =>	compute(&|a, b| { a ^ b }),
-			RISCV_OPI_ORI =>	compute(&|a, b| { a | b }),
-			RISCV_OPI_ANDI =>	compute(&|a, b| { a & b }),
-			RISCV_OPI_SLLI =>	compute(&|a, b| { a << b }),
-			RISCV_OPI_SRI =>	{
-									if inst.funct7_smaller == RISCV_OPI_SRI_SRLI {
-										self.int_reg.set_reg(inst.rd, (self.int_reg.get_reg(inst.rs1) >> inst.shamt) & self.shiftmask[inst.shamt as usize] as i64)
-									} else { // SRAI
-										self.int_reg.set_reg(inst.rd, self.int_reg.get_reg(inst.rs1) >> inst.shamt)
-									}
-									Ok(())
+			RISCV_OPI_ADDI =>	compute(&std::ops::Add::add, rs1, imm12),
+			RISCV_OPI_SLTI =>	compute(&|a, b| (a < b) as i64, rs1, imm12),
+			RISCV_OPI_XORI =>	compute(&core::ops::BitXor::bitxor, rs1, imm12),
+			RISCV_OPI_ORI =>	compute(&core::ops::BitOr::bitor, rs1, imm12),
+			RISCV_OPI_ANDI =>	compute(&core::ops::BitAnd::bitand, rs1, imm12),
+			RISCV_OPI_SLLI =>	compute(&core::ops::Shl::shl, rs1, imm12),
+			RISCV_OPI_SRI =>	if inst.funct7_smaller == RISCV_OPI_SRI_SRLI {
+									compute(&|a, b| { (a >> b) & self.shiftmask[inst.shamt as usize] as i64 }, rs1, shamt)
+								} else {
+									compute(&|a, b| { a >> b }, rs1, shamt)
 								}
 			_ =>				Err(MachineError::new(format!("In OPI switch case, this should never happen... Instr was %x\n {}", inst.value).as_str()))
 		}