diff --git a/compressed_decoder.sv b/compressed_decoder.sv
index 39b908ee..ec49d378 100644
--- a/compressed_decoder.sv
+++ b/compressed_decoder.sv
@@ -52,26 +52,28 @@ module compressed_decoder
         unique case (instr_i[15:13])
           3'b000: begin
             if (instr_i[12] == 1'b0) begin
-              // c.mv -> add rd, x0, rs2
+              // c.mv -> add rd/rs1, x0, rs2
               instr_o = {7'b0, instr_i[6:2], 5'b0, 3'b0, instr_i[11:7], `OPCODE_OP};
+
+              if (instr_i[6:2] == 5'b0) begin
+                // c.jr -> jalr x0, rd/rs1, 0
+                instr_o = {12'b0, instr_i[11:7], 3'b0, 5'b0, `OPCODE_JALR};
+              end
             end else begin
               // c.add -> add rd, rd, rs2
               instr_o = {7'b0, instr_i[6:2], instr_i[11:7], 3'b000, instr_i[11:7], `OPCODE_OP};
-            end
-            if (instr_i[11:7] == 5'b0) begin
-              if (instr_i[6:2] == 5'b0)
-                instr_o = {32'h00_10_00_73}; // EBREAK
-              else
-                illegal_instr_o = 1'b1;
-            end
-          end
 
-          3'b001: begin
-            // c.srai -> srai rd, rd, shamt
-            instr_o = {2'b01, 5'b0, instr_i[6:2], instr_i[11:7], 3'b101, instr_i[11:7], `OPCODE_OPIMM};
-            if (instr_i[12] != 1'b0)   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;
+              if (instr_i[11:7] == 5'b0) begin
+                // c.ebreak -> ebreak
+                instr_o = {32'h00_10_00_73};
+                if (instr_i[6:2] != 5'b0)
+                  illegal_instr_o = 1'b1;
+              end else if (instr_i[6:2] == 5'b0) begin
+                // c.jalr -> jalr x1, rs1, 0
+                instr_o = {12'b0, instr_i[11:7], 3'b000, 5'b00001, `OPCODE_JALR};
+              end
+            end
+
           end
 
           3'b010: begin
@@ -79,57 +81,9 @@ module compressed_decoder
             instr_o = {5'b0, instr_i[5], instr_i[12], 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b010, instr_i[11:10], instr_i[6], 2'b00, `OPCODE_STORE};
           end
 
-          3'b011: begin
-            instr_o = {7'b0, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b0, 2'b01, instr_i[9:7], `OPCODE_OP};
-
-            unique case ({instr_i[12:10], instr_i[6:5]})
-              // c.xor -> xor rd', rd', rs2'
-              5'b00000: instr_o = {7'b000_0000, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b100, 2'b01, instr_i[9:7], `OPCODE_OP};
-
-              // c.sll -> sll rd', rd', rs2'
-              5'b00100: instr_o = {7'b000_0000, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b001, 2'b01, instr_i[9:7], `OPCODE_OP};
-              // c.srl -> srl rd', rd', rs2'
-              5'b00101: instr_o = {7'b000_0000, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b101, 2'b01, instr_i[9:7], `OPCODE_OP};
-              // c.sra -> sra rd', rd', rs2'
-              5'b00001: instr_o = {7'b010_0000, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b101, 2'b01, instr_i[9:7], `OPCODE_OP};
-              // c.sltu -> sltu rd', rd', rs2'
-              5'b00111: instr_o = {7'b000_0000, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b011, 2'b01, instr_i[9:7], `OPCODE_OP};
-
-              // c.sllr -> sll rd', rs1', rd'
-              5'b01100: instr_o = {7'b000_0000, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b001, 2'b01, instr_i[4:2], `OPCODE_OP};
-              // c.srlr -> srl rd', rs1', rd'
-              5'b01101: instr_o = {7'b000_0000, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b101, 2'b01, instr_i[4:2], `OPCODE_OP};
-              // c.sltur -> sltu rd', rs1', rd'
-              5'b01111: instr_o = {7'b000_0000, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b011, 2'b01, instr_i[4:2], `OPCODE_OP};
-
-              // c.slt -> slt rd', rd', rs2'
-              5'b00110: instr_o = {7'b000_0000, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b010, 2'b01, instr_i[9:7], `OPCODE_OP};
-              // c.sltr -> slt rd', rs1', rd'
-              5'b01110: instr_o = {7'b000_0000, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b010, 2'b01, instr_i[4:2], `OPCODE_OP};
-
-              default:  illegal_instr_o = 1'b1;
-            endcase
-          end
-
           3'b100: begin
-            // c.sub -> sub rd, rd rs2
-            instr_o = {2'b01, 5'b0, instr_i[6:2], instr_i[11:7], 3'b000, instr_i[11:7], `OPCODE_OP};
-            if (instr_i[12] != 1'b0)   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'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 -> sub rd', rs1', rs2'
-              2'b01:  instr_o = {2'b01, 5'b0, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b000, 2'b01, instr_i[12:10], `OPCODE_OP};
-              // 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};
-            endcase
+            // c.addi4spn -> addi rd', x2, imm
+            instr_o = {2'b0, instr_i[10:7], instr_i[12:11], instr_i[5], instr_i[6], 2'b00, 5'h02, 3'b000, 2'b01, instr_i[4:2], `OPCODE_OPIMM};
           end
 
           3'b110: begin
@@ -153,54 +107,17 @@ module compressed_decoder
             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};
           end
 
-          3'b011: begin
-            // c.bltz -> blt rs1', x0, imm
-            instr_o = {{3 {instr_i[12]}}, instr_i[12:10], instr_i[2], 5'b0, 2'b01, instr_i[9:7], 3'b100, instr_i[6:3], instr_i[12], `OPCODE_BRANCH};
-          end
-
-          3'b100: begin
-            unique case (instr_i[6:5])
-              // c.addin -> addi rd', rs1', imm
-              2'b00:  instr_o = {{9 {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 = {{9 {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 = {{9 {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
-              2'b11:  instr_o = {{9 {instr_i[12]}}, instr_i[12:10], 2'b01, instr_i[9:7], 3'b111, 2'b01, instr_i[4:2], `OPCODE_OPIMM};
-            endcase
-            if (instr_i[12:10] == 3'b0) illegal_instr_o = 1'b1;
-          end
-
-          3'b101: begin
-            // c.addi4spn -> addi rd', x2, imm
-            instr_o = {2'b0, instr_i[10:7], instr_i[12:11], instr_i[5], instr_i[6], 2'b00, 5'h02, 3'b000, 2'b01, instr_i[4:2], `OPCODE_OPIMM};
-          end
-
           3'b110: begin
             // c.lwsp -> lw rd, imm(x2)
             instr_o = {4'b0, instr_i[3:2], instr_i[12], instr_i[6:4], 2'b00, 5'h02, 3'b010, instr_i[11:7], `OPCODE_LOAD};
             if (instr_i[11:7] == 5'b0)  illegal_instr_o = 1'b1;
           end
 
-          3'b111: begin
-            // c.bgez -> bge rs1', x0, imm
-            instr_o = {{3 {instr_i[12]}}, instr_i[12:10], instr_i[2], 5'b0, 2'b01, instr_i[9:7], 3'b101, instr_i[6:3], instr_i[12], `OPCODE_BRANCH};
-          end
-
           default: begin
             illegal_instr_o = 1'b1;
           end
@@ -223,44 +140,28 @@ module compressed_decoder
           end
 
           3'b100: begin
-            if ({instr_i[12], instr_i[6:2]} == 6'b0) begin
-              // c.jr -> jalr x0, rs1, 0
-              instr_o = {12'b0, instr_i[11:7], 3'b0, 5'b0, `OPCODE_JALR};
-            end else begin
-              // c.li -> addi rd, x0, nzimm
-              instr_o = {{6 {instr_i[12]}}, instr_i[12], instr_i[6:2], 5'b0, 3'b0, instr_i[11:7], `OPCODE_OPIMM};
-            end
+            // c.li -> addi rd, x0, nzimm
+            instr_o = {{6 {instr_i[12]}}, instr_i[12], instr_i[6:2], 5'b0, 3'b0, instr_i[11:7], `OPCODE_OPIMM};
+
             if (instr_i[11:7] == 5'b0)  illegal_instr_o = 1'b1;
           end
 
           3'b101: begin
-            if ({instr_i[12], instr_i[6:2]} == 6'b0) begin
-              // c.jalr -> jalr x1, rs1, 0
-              instr_o = {12'b0, instr_i[11:7], 3'b000, 5'b00001, `OPCODE_JALR};
-            end else begin
-              // c.lui -> lui rd, imm
-              instr_o = {{15 {instr_i[12]}}, instr_i[6:2], instr_i[11:7], `OPCODE_LUI};
+            // c.lui -> lui rd, imm
+            instr_o = {{15 {instr_i[12]}}, instr_i[6:2], instr_i[11:7], `OPCODE_LUI};
+
+            if (instr_i[11:7] == 5'b0) begin
+              // c.addi16sp -> addi x2, x2, nzimm
+              instr_o = {{3 {instr_i[12]}}, instr_i[4:2], instr_i[5], instr_i[6], 4'b0, 5'h02, 3'b000, 5'h02, `OPCODE_OPIMM};
             end
 
-            if (instr_i[11:7] == 5'b0)  illegal_instr_o = 1'b1;
+            if ({instr_i[12], instr_i[6:2]} == 6'b0) illegal_instr_o = 1'b1;
           end
 
           3'b110: begin
-            if (instr_i[11:7] == 5'b0) begin
-              // c.addi16sp -> addi x2, x2, nzimm
-              // c.nop
-              instr_o = {{3 {instr_i[12]}}, instr_i[4:2], instr_i[5], instr_i[6], 4'b0, 5'h02, 3'b000, 5'h02, `OPCODE_OPIMM};
-            end else begin
-              // c.addi -> addi rd, rd, nzimm
-              instr_o = {{6 {instr_i[12]}}, instr_i[12], instr_i[6:2], instr_i[11:7], 3'b0, instr_i[11:7], `OPCODE_OPIMM};
-              if ({instr_i[12], instr_i[6:2]} == 6'b0)  illegal_instr_o = 1'b1;
-            end
-          end
-
-          3'b111: begin
-            // c.andi -> andi rd, rd, nzimm
-            instr_o = {{6 {instr_i[12]}}, instr_i[12], instr_i[6:2], instr_i[11:7], 3'b111, instr_i[11:7], `OPCODE_OPIMM};
-            if (instr_i[11:7] == 5'b0)  illegal_instr_o = 1'b1;
+            // c.addi -> addi rd, rd, nzimm
+            // c.nop
+            instr_o = {{6 {instr_i[12]}}, instr_i[12], instr_i[6:2], instr_i[11:7], 3'b0, instr_i[11:7], `OPCODE_OPIMM};
           end
 
           default: begin