Add Zbs single-bit operations implementation (RV32, SystemVerilog)

.gitignore

@@ -31,3 +31,4 @@ out/**
 !out/.gitkeep
 build/**
 !build/.gitkeep
+.DS_Store

src/ext/b/decoder.sv

@@ -4,25 +4,28 @@
 /* verilator lint_off DECLFILENAME */
 module ext__b__decoder
 /* verilator lint_on DECLFILENAME */
-  ( input [2:0] funct3
-  , input [6:0] funct7
-  , input opcode_t opcode
+  ( input  [2:0] funct3
+  , input  [6:0] funct7
+  , input  opcode_t opcode
   /* verilator lint_off UNUSEDSIGNAL */
-  , input reg_t rd
+  , input  reg_t rd
   /* verilator lint_on UNUSEDSIGNAL */
-  , input reg_t rs2
+  , input  reg_t rs2
   , output ext__b__types::b_alu_control_t b_alu_control
   );
 
   import ext__b__types::*;
 
-  localparam bit [6:0] FUNCT7_ZBA = 7'b0010000;
-  localparam bit [6:0] FUNCT7_ZBB__LOGICAL = 7'b0100000;
-  localparam bit [6:0] FUNCT7_ZBB__MINMAX = 7'b0000101;
-  localparam bit [6:0] FUNCT7_ZBB__ZEXT = 7'b0000100;
-  localparam bit [6:0] FUNCT7_ZBB__ROTATE = 7'b0110000;
-  localparam bit [6:0] FUNCT7_ZBB__ORCB  = 7'b0010100;
-  localparam bit [6:0] FUNCT7_ZBB__REV8  = 7'b0110100;
+  localparam bit [6:0] FUNCT7_ZBA         = 7'b0010000;
+  localparam bit [6:0] FUNCT7_ZBB_LOGICAL  = 7'b0100000;
+  localparam bit [6:0] FUNCT7_ZBB_MINMAX   = 7'b0000101;
+  localparam bit [6:0] FUNCT7_ZBB_ZEXT     = 7'b0000100;
+  localparam bit [6:0] FUNCT7_ZBB_ROTATE   = 7'b0110000;
+  localparam bit [6:0] FUNCT7_ZBB_ORCB     = 7'b0010100;
+  localparam bit [6:0] FUNCT7_ZBB_REV8     = 7'b0110100;
+  localparam bit [6:0] FUNCT7_ZBB__BSET    = 7'b0010100;
+  localparam bit [6:0] FUNCT7_ZBB__BCLR    = 7'b0100100;
+  localparam bit [6:0] FUNCT7_ZBB__BINV    = 7'b0110100;
 
   always_comb
     case (opcode)
@@ -36,78 +39,111 @@ module ext__b__decoder
               default: b_alu_control = B_ALU_CTRL__NONE;
             endcase
 
-          FUNCT7_ZBB__LOGICAL:
+          FUNCT7_ZBB_LOGICAL:
             case (funct3)
               3'b111:  b_alu_control = B_ALU_CTRL__ANDN;
               3'b110:  b_alu_control = B_ALU_CTRL__ORN;
               3'b100:  b_alu_control = B_ALU_CTRL__XNOR;
               default: b_alu_control = B_ALU_CTRL__NONE;
             endcase
-          FUNCT7_ZBB__MINMAX:
+
+          FUNCT7_ZBB_MINMAX:
             case (funct3)
               3'b100:  b_alu_control = B_ALU_CTRL__MIN;
               3'b101:  b_alu_control = B_ALU_CTRL__MINU;
               3'b110:  b_alu_control = B_ALU_CTRL__MAX;
               3'b111:  b_alu_control = B_ALU_CTRL__MAXU;
               default: b_alu_control = B_ALU_CTRL__NONE;
             endcase
-          FUNCT7_ZBB__ROTATE:
+
+          FUNCT7_ZBB_ROTATE:
             case (funct3)
               3'b001:  b_alu_control = B_ALU_CTRL__ROL;
               3'b101:  b_alu_control = B_ALU_CTRL__ROR;
               default: b_alu_control = B_ALU_CTRL__NONE;
             endcase
-          FUNCT7_ZBB__ZEXT:
+
+          FUNCT7_ZBB_ZEXT:
             case (funct3)
               3'b100:
                 case (rs2)
                   5'b00000: b_alu_control = B_ALU_CTRL__ZEXTH;
-                  default: b_alu_control = B_ALU_CTRL__NONE;
+                  default:   b_alu_control = B_ALU_CTRL__NONE;
                 endcase
               default: b_alu_control = B_ALU_CTRL__NONE;
             endcase
-          // TODO: Implement zbs into ALU decoder, also confirm what zbb instructions are being implemented.
-          default: b_alu_control = B_ALU_CTRL__NONE;
 
+          FUNCT7_ZBB__BSET:
+            if (funct3 == 3'b001)
+              b_alu_control = B_ALU_CTRL__BSET;
+            else
+              b_alu_control = B_ALU_CTRL__NONE;
+
+          FUNCT7_ZBB__BCLR:
+            case (funct3)
+              3'b001: b_alu_control = B_ALU_CTRL__BCLR;
+              3'b101: b_alu_control = B_ALU_CTRL__BEXT;
+              default: b_alu_control = B_ALU_CTRL__NONE;
+            endcase
+
+          FUNCT7_ZBB__BINV:
+            if (funct3 == 3'b001)
+              b_alu_control = B_ALU_CTRL__BINV;
+            else
+              b_alu_control = B_ALU_CTRL__NONE;
+
+          default: b_alu_control = B_ALU_CTRL__NONE;
         endcase
+
       7'b0010011:
         case (funct7)
           7'b0110000:
             case (funct3)
               3'b001:
                 case (rs2)
-                  5'b00100:  b_alu_control = B_ALU_CTRL__SEXTB;
-                  5'b00101:  b_alu_control = B_ALU_CTRL__SEXTH;
-                  5'b00000:  b_alu_control = B_ALU_CTRL__CLZ;
-                  5'b00001:  b_alu_control = B_ALU_CTRL__CTZ;
-                  5'b00010:  b_alu_control = B_ALU_CTRL__CPOP;
+                  5'b00100: b_alu_control = B_ALU_CTRL__SEXTB;
+                  5'b00101: b_alu_control = B_ALU_CTRL__SEXTH;
+                  5'b00000: b_alu_control = B_ALU_CTRL__CLZ;
+                  5'b00001: b_alu_control = B_ALU_CTRL__CTZ;
+                  5'b00010: b_alu_control = B_ALU_CTRL__CPOP;
                   default:   b_alu_control = B_ALU_CTRL__NONE;
                 endcase
               3'b101: b_alu_control = B_ALU_CTRL__RORI;
               default: b_alu_control = B_ALU_CTRL__NONE;
             endcase
-            FUNCT7_ZBB__ORCB:
+
+          FUNCT7_ZBB_ORCB:
             case (funct3)
               3'b101:
                 case (rs2)
                   5'b00111: b_alu_control = B_ALU_CTRL__ORCB;
-                  default:  b_alu_control = B_ALU_CTRL__NONE;
+                  default:   b_alu_control = B_ALU_CTRL__NONE;
                 endcase
+              3'b001: b_alu_control = B_ALU_CTRL__BSET;
               default: b_alu_control = B_ALU_CTRL__NONE;
             endcase
 
-          FUNCT7_ZBB__REV8:
+          FUNCT7_ZBB_REV8:
             case (funct3)
               3'b101:
                 case (rs2)
                   5'b11000: b_alu_control = B_ALU_CTRL__REV8;
-                  default:  b_alu_control = B_ALU_CTRL__NONE;
+                  default:   b_alu_control = B_ALU_CTRL__NONE;
                 endcase
+              3'b001: b_alu_control = B_ALU_CTRL__BINV;
+              default: b_alu_control = B_ALU_CTRL__NONE;
+            endcase
+
+          FUNCT7_ZBB__BCLR:
+            case (funct3)
+              3'b001: b_alu_control = B_ALU_CTRL__BCLR;
+              3'b101: b_alu_control = B_ALU_CTRL__BEXT;
               default: b_alu_control = B_ALU_CTRL__NONE;
             endcase
 
           default: b_alu_control = B_ALU_CTRL__NONE;
         endcase
+
       default: b_alu_control = B_ALU_CTRL__NONE;
     endcase
 

src/ext/b/types.svh

@@ -3,7 +3,6 @@
 
 /* verilator lint_off DECLFILENAME */
 package ext__b__types;
-/* verilator lint_on DECLFILENAME */
   typedef enum logic [4:0]
     { B_ALU_CTRL__NONE   = 5'b00000
     , B_ALU_CTRL__SH1ADD = 5'b00001
@@ -27,6 +26,10 @@ package ext__b__types;
     , B_ALU_CTRL__RORI   = 5'b10011
     , B_ALU_CTRL__ORCB   = 5'b10100
     , B_ALU_CTRL__REV8   = 5'b10101
+    , B_ALU_CTRL__BCLR   = 5'b10110
+    , B_ALU_CTRL__BSET   = 5'b10111
+    , B_ALU_CTRL__BINV   = 5'b11000
+    , B_ALU_CTRL__BEXT   = 5'b11001
     } b_alu_control_t;
 
 endpackage

src/ext/b/zbs.sv

@@ -0,0 +1,23 @@
+`include "src/timescale.svh"
+`include "src/headers/types.svh"
+`include "src/ext/b/types.svh"
+
+module zbs
+  ( input  data_t                         reg1
+  , input  logic [4:0]                    reg2
+  , input  ext__b__types::b_alu_control_t  b_alu_control
+  , output data_t                         out
+);
+
+  import ext__b__types::*;
+
+  always_comb
+    case (b_alu_control)
+      B_ALU_CTRL__BCLR: out = reg1 & ~(data_t'(32'h1) << reg2);
+      B_ALU_CTRL__BSET: out = reg1 | (data_t'(32'h1) << reg2);
+      B_ALU_CTRL__BINV: out = reg1 ^ (data_t'(32'h1) << reg2);
+      B_ALU_CTRL__BEXT: out = (reg1 >> reg2) & data_t'(32'h1);
+      default:          out = '0;
+    endcase
+
+endmodule