diff --git a/src/machine.rs b/src/machine.rs
index 2bb70f7..58f66a5 100644
--- a/src/machine.rs
+++ b/src/machine.rs
@@ -9,7 +9,8 @@ pub struct Machine {
 	pub pc : u32,
 	pub int_reg : [u32 ; 32],
 	pub instructions : [u32 ; 100],
-	pub main_memory : [u8 ; MEM_SIZE]
+	pub main_memory : [u8 ; MEM_SIZE],
+	pub shiftmask : [u32 ; 32]
 	// futur taille à calculer int memSize = g_cfg->NumPhysPages * g_cfg->PageSize;
 	//creer une struct cfg(configuration) qui s'initialise avec valeur dans un fichier cfg
 }
@@ -18,12 +19,21 @@ pub struct Machine {
 impl Machine {
 
 	pub fn _init_machine() -> Machine {	
+		let mut shiftmask : [u32 ; 32] = [0 ; 32];
+		let mut value : u32 = 0xffff;
+
+		value = (value << 16) + value;
+		for i in 0..32 {
+			shiftmask[i] = value;
+			value = value >> 1;
+		}
 
 		Machine {
 			pc : 0,
 			instructions : [0 ; 100],
 			int_reg : [0 ; 32],
-			main_memory : [0 ; MEM_SIZE]
+			main_memory : [0 ; MEM_SIZE],
+			shiftmask : shiftmask
 		}	
 	}
 
@@ -68,6 +78,13 @@ impl Machine {
 					},
 					RISCV_OPI_SLLI => {
 						machine.int_reg[inst.rd as usize] = machine.int_reg[inst.rs1 as usize] << inst.shamt;
+					},
+					RISCV_OPI_SRI => {
+						if inst.funct7_smaller == RISCV_OPI_SRI_SRLI {
+							machine.int_reg[inst.rd as usize] = (machine.int_reg[inst.rs1 as usize] >> inst.shamt) & machine.shiftmask[inst.shamt as usize];
+						} else { // SRAI
+							machine.int_reg[inst.rd as usize] = (machine.int_reg[inst.rs1 as usize] >> inst.shamt);	
+						}
 					}
 					_ => { println!("{} inconnu", inst.funct3); }
 				}
@@ -123,6 +140,65 @@ impl Machine {
 						println!("RISCV_OP undefined case\n");
 					}
 				}
+			},
+			//******************************************************************************************
+    		// Treatment for: OPW INSTRUCTIONS
+			RISCV_OPW => {
+				if inst.funct7 == 1 {
+					let localDataa = machine.int_reg[inst.rs1 as usize] & 0xffffffff;
+					let localDatab = machine.int_reg[inst.rs2 as usize] & 0xffffffff;
+					let localDataaUnsigned = machine.int_reg[inst.rs1 as usize] & 0xffffffff;
+					let localDatabUnsigned = machine.int_reg[inst.rs2 as usize] & 0xffffffff;
+
+					// Match case for multiplication operations (in standard extension RV32M)
+					match inst.funct3 {
+						RISCV_OPW_M_MULW => {
+							machine.int_reg[inst.rd as usize] = localDataa * localDatab;
+						},
+						RISCV_OPW_M_DIVW => {
+							machine.int_reg[inst.rd as usize] = localDataa / localDatab;
+						},
+						RISCV_OPW_M_DIVUW => {
+							machine.int_reg[inst.rd as usize] = localDataaUnsigned / localDatabUnsigned;
+						},
+						RISCV_OPW_M_REMW => {
+							machine.int_reg[inst.rd as usize] = localDataa % localDatab;
+						},
+						RISCV_OPW_M_REMUW => {
+							machine.int_reg[inst.rd as usize] = localDataaUnsigned % localDatabUnsigned;
+						},
+						_ => {
+							println!("this instruction ({}) doesn't exists", inst.value);
+						}
+					}
+				} else {
+					let localDataa = machine.int_reg[inst.rs1 as usize] & 0xffffffff;
+					let localDatab = machine.int_reg[inst.rs2 as usize] & 0xffffffff;
+
+					// Match case for base OP operation
+					match inst.funct3 {
+						RISCV_OPW_ADDSUBW => {
+							if inst.funct7 == RISCV_OPW_ADDSUBW_ADDW {
+								machine.int_reg[inst.rd as usize] = localDataa + localDatab;
+							} else { // SUBW
+								machine.int_reg[inst.rd as usize] = localDataa - localDatab;
+							}
+						},
+						RISCV_OPW_SLLW => {
+							machine.int_reg[inst.rd as usize] = localDataa << (localDatab & 0x1f);
+						},
+						RISCV_OPW_SRW => {
+							if inst.funct7 == RISCV_OPW_SRW_SRLW {
+								machine.int_reg[inst.rd as usize] = localDataa >> (localDatab & 0x1f) & machine.shiftmask[32 + localDatab as usize];
+							} else { // SRAW
+								machine.int_reg[inst.rd as usize] = localDataa >> (localDatab & 0x1f);
+							}
+						},
+						_ => {
+							println!("this instruction ({}) doesn't exists", inst.value);
+						}
+					}
+				}
 			}
 			_ => { println!("{} opcode non géré", inst.opcode)},
 		}
diff --git a/src/print.rs b/src/print.rs
index 4aa70b0..788a6bd 100644
--- a/src/print.rs
+++ b/src/print.rs
@@ -130,6 +130,38 @@ pub const RISCV_FP_FCMP_FLE: u8 = 0;
 
 pub const RISCV_FP_FMVW: u8 = 0x78;
 
+pub const RISCV_OP_M: u8 = 0x1;
+
+pub const RISCV_OP_M_MUL: u8 = 0x0;
+pub const RISCV_OP_M_MULH: u8 = 0x1;
+pub const RISCV_OP_M_MULHSU: u8 = 0x2;
+pub const RISCV_OP_M_MULHU: u8 = 0x3;
+pub const RISCV_OP_M_DIV: u8 = 0x4;
+pub const RISCV_OP_M_DIVU: u8 = 0x5;
+pub const RISCV_OP_M_REM: u8 = 0x6;
+pub const RISCV_OP_M_REMU: u8 = 0x7;
+
+pub const RISCV_OPW_M_MULW: u8 = 0x0;
+pub const RISCV_OPW_M_DIVW: u8 = 0x4;
+pub const RISCV_OPW_M_DIVUW: u8 = 0x5;
+pub const RISCV_OPW_M_REMW: u8 = 0x6;
+pub const RISCV_OPW_M_REMUW: u8 = 0x7;
+
+pub const RISCV_FENCE: u8 = 0x0f;
+
+pub const RISCV_ATOM: u8 = 0x2f;
+pub const RISCV_ATOM_LR: u8 = 0x2;
+pub const RISCV_ATOM_SC: u8 = 0x3;
+pub const RISCV_ATOM_SWAP: u8 = 0x1;
+pub const RISCV_ATOM_ADD: u8 = 0;
+pub const RISCV_ATOM_XOR: u8 = 0x4;
+pub const RISCV_ATOM_AND: u8 = 0xc;
+pub const RISCV_ATOM_OR: u8 = 0x8;
+pub const RISCV_ATOM_MIN: u8 = 0x10;
+pub const RISCV_ATOM_MAX: u8 = 0x14;
+pub const RISCV_ATOM_MINU: u8 = 0x18;
+pub const RISCV_ATOM_MAXU: u8 = 0x1c;
+
 
 const names_op: [&str; 8] = ["add", "sll", "slt", "sltu", "xor", "sr", "or", "and"];
 const names_opi: [&str; 8]  = ["addi", "slli", "slti", "sltiu", "xori", "slri", "ori", "andi"];