diff --git a/compressed_decoder.sv b/compressed_decoder.sv
index 1909aea0..6e20316c 100644
--- a/compressed_decoder.sv
+++ b/compressed_decoder.sv
@@ -69,19 +69,26 @@ module compressed_decoder
 
           3'b011: begin
             unique case ({instr_i[12:10], instr_i[6:5]})
-              5'b00000: begin
-                // c.xor -> xor rd', rd', rs2'
-                instr_o = {7'b0, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b100, 2'b01, instr_i[9:7], `OPCODE_OP};
-              end
+              // c.xor -> xor rd', rd', rs2'
+              5'b00000: instr_o = {7'b0, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b100, 2'b01, instr_i[9:7], `OPCODE_OP};
+              // c.sltr
+              // c.sltur -> sltu rd', rs1', rd'
+              5'b01111: instr_o = {7'b0, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b011, 2'b01, instr_i[4:2], `OPCODE_OP};
               default:  illegal_instr_o = 1'b1;
             endcase
           end
 
           3'b101: begin
             unique case (instr_i[6:5])
+              // c.add3 -> add rd', rs1', rs2'
+              2'b00:  instr_o = {7'b0, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b000, 2'b01, instr_i[12:10], `OPCODE_OP};
+
+              // c.sub3
+
+              // c.or3 -> or rd'1, rs1', rs2'
+              2'b10:  instr_o = {7'b0, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b110, 2'b01, instr_i[12:10], `OPCODE_OP};
               // c.and3 -> and rd', rs1', rs2'
               2'b11:  instr_o = {7'b0, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b111, 2'b01, instr_i[12:10], `OPCODE_OP};
-
               default:  illegal_instr_o = 1'b1;
             endcase
           end
@@ -102,11 +109,19 @@ module compressed_decoder
         unique case (instr_i[15:13])
           3'b000: begin
             // c.slli -> slli rd, rd, shamt
-            instr_o = {6'b0, instr_i[12], instr_i[6:2], instr_i[11:7], 3'b001, instr_i[11:7], `OPCODE_OPIMM};
+            instr_o = {7'b0, instr_i[6:2], instr_i[11:7], 3'b001, instr_i[11:7], `OPCODE_OPIMM};
             if (instr_i[11:7] == 5'b0)  illegal_instr_o = 1'b1;
             if (instr_i[12] == 1'b1 || instr_i[6:2] == 5'b0)  illegal_instr_o = 1'b1;
           end
 
+          3'b001: begin
+            // c.srli -> srli rd, rd, shamt
+            instr_o = {7'b0, instr_i[6:2], instr_i[11:7], 3'b101, instr_i[11:7], `OPCODE_OPIMM};
+            if (instr_i[12] == 1'b1)   illegal_instr_o = 1'b1;
+            if (instr_i[6:2] == 5'b0)  illegal_instr_o = 1'b1;
+            if (instr_i[11:7] == 5'b0) illegal_instr_o = 1'b1;
+          end
+
           3'b010: begin
             // c.swsp -> sw rs2, imm(x2)
             instr_o = {4'b0, instr_i[8:7], instr_i[12], instr_i[6:2], 5'h02, 3'b010, instr_i[11:9], 2'b00, `OPCODE_STORE};
@@ -114,6 +129,10 @@ module compressed_decoder
 
           3'b100: begin
             unique case (instr_i[6:5])
+              // c.addin -> addi rd', rs1', imm
+              2'b00:  instr_o = {{8 {instr_i[12]}}, instr_i[12:10], 2'b01, instr_i[9:7], 3'b000, 2'b01, instr_i[4:2], `OPCODE_OPIMM};
+              // c.xorin -> xori rd', rs1', imm
+              2'b01:  instr_o = {{8 {instr_i[12]}}, instr_i[12:10], 2'b01, instr_i[9:7], 3'b100, 2'b01, instr_i[4:2], `OPCODE_OPIMM};
               // c.orin -> ori rd', rs1', imm
               2'b10:  instr_o = {{8 {instr_i[12]}}, instr_i[12:10], 2'b01, instr_i[9:7], 3'b110, 2'b01, instr_i[4:2], `OPCODE_OPIMM};
               // c.andin -> andi rd', rs1', imm