datatypes.lv

;;; Simple uses of structs and enums

(enum ternary
  ::false   2'b00
  ::true    2'b01
  ::unknown 2'b11)

(enum kind
  ::add 8'b01010000
  ::lsr 8'b01100000)

(struct instr
  :kind 'kind
  :imm1 (bits 12)
  :imm2 (bits 12))

(enum has_x_1
  ::x 5'b0)

(enum has_x_2
  ::x 5'b0)

(extfun getinstr ((idx (bits 32))) (bits 32))

(defun decode ((bs (bits 32)))
  'instr
  (unpack 'instr bs))

(defun eval ((i 'instr))
  (bits 12)
  (switch (get :kind i)
    (::add (+ (get :imm1 i) (get :imm2 i)))
    (::lsr (>> (get :imm1 i) (get :imm2 i)))
    (_     12'hfff)))

(module datatypes
  (register raddr 32'0)
  (register rinstr 32'0)
  (register routput 32'0)

  (cpp-preamble "
static constexpr bits<32> instructions[8] = {
  32'11011000001011000000011111001101_b,
  32'01101011101010101001010001010101_b,
  32'10000010111000101110011001100010_b,
  32'01111010000000100100001000000100_b,
  32'11101000011110100001011000010011_b,
  32'10000001001100110010100001110110_b,
  32'01001000001001101000011001110011_b,
  32'11000001011111000110001001111001_b
};

class extfuns {
public:
  bits<32> getinstr(const bits<32> idx) {
    return instructions[idx.v % 8];
  }
};")

  (rule readinstr
    (write.0 raddr (+ (read.0 raddr) 32'1))
    (write.0 rinstr (getinstr (read.0 raddr))))

  (rule runinstr
    (let ((x 5'b0)
          (i (decode (read.1 rinstr)))
          (i2 (init 'instr :kind ::add :imm1 12'0 :imm2 12'b111111111111)))
      (setq x (+ x 5'b00010))
      (write.0 routput
        (zextl 32 (+ (eval i) (eval i2))))))

  (register scratch 1'b0)

  (rule test_name_resolution
    (progn
      (write.0 scratch (eq (unpack 'has_x_1 5'0) has_x_1::x))
      (write.0 scratch (eq (unpack 'has_x_2 5'0) has_x_2::x))
      (write.0 scratch (eq (unpack 'has_x_2 5'0) ::x))))

  (scheduler main
    (sequence test_name_resolution readinstr runinstr)))