verilator/test_regress/t/t_math_precedence.v

// DESCRIPTION: Verilator: Verilog Test module
//
// This file ONLY is placed under the Creative Commons Public Domain.
// SPDX-FileCopyrightText: 2009 Wilson Snyder
// SPDX-License-Identifier: CC0-1.0

module t (  /*AUTOARG*/
    // Inputs
    clk
);
  input clk;

  integer cyc = 0;
  reg [63:0] crc;
  reg [63:0] sum;

  wire [1:0] a = crc[1+:2];
  wire [1:0] b = crc[3+:2];
  wire [1:0] c = crc[5+:2];
  wire [1:0] d = crc[7+:2];
  wire [1:0] e = crc[9+:2];
  wire [1:0] f = crc[11+:2];
  wire [1:0] g = crc[13+:2];

  //   left    () [] :: .
  //   unary   + - ! ~ & ~& | ~| ^ ~^ ^~ ++ -- (unary)
  //   left    **
  //   left    * / %
  //   left    + - (binary)
  //   left    << >> <<< >>>
  //   left    < <= > >= inside dist
  //   left    == != === !== ==? !=?
  //   left    & (binary)
  //   left    ^ ~^ ^~ (binary)
  //   left    | (binary)
  //   left    &&
  //   left    ||
  //   left    ? :
  //   right   ->
  //   none    = += -= *= /= %= &= ^= |= <<= >>= <<<= >>>= := :/ <=
  //           {} {{}} concatenation

  wire [1:0] bnz = (b == 2'b0) ? 2'b11 : b;
  wire [1:0] cnz = (c == 2'b0) ? 2'b11 : c;
  wire [1:0] dnz = (d == 2'b0) ? 2'b11 : d;
  wire [1:0] enz = (e == 2'b0) ? 2'b11 : e;

  // verilator lint_off WIDTH
  // Do a few in each group
  wire [1:0] o1 = ~a;  // Can't get more than one reduction to parse
  wire [1:0] o2 = ^b;  // Can't get more than one reduction to parse
  wire [1:0] o3 = a ** b ** c;  // Some simulators botch this

  wire [1:0] o4 = a * b / cnz % dnz * enz;
  wire [1:0] o5 = a + b - c + d;
  wire [1:0] o6 = a << b >> c <<< d >>> e <<< f;
  wire [1:0] o7 = a < b <= c;
  wire [1:0] o8 = a == b != c === d == e;
  wire [1:0] o9 = a & b & c;
  wire [1:0] o10 = a ^ b ~^ c ^~ d ^ a;
  wire [1:0] o11 = a | b | c;
  wire [1:0] o12 = a && b && c;
  wire [1:0] o13 = a || b || c;
  wire [1:0] o14 = a ? b ? c : d : e;
  wire [1:0] o15 = a ? b : c ? d : e;

  // Now cross each pair of groups
  wire [1:0] x1 = ~a ** ~b ** ~c;  // Some simulators botch this
  wire [1:0] x2 = a ** b * c ** d;  // Some simulators botch this
  wire [1:0] x3 = a + b * c + d;
  wire [1:0] x4 = a + b << c + d;
  wire [1:0] x5 = a == b << c == d;
  wire [1:0] x6 = a & b << c & d;
  wire [1:0] x7 = a ^ b & c ^ d;
  wire [1:0] x8 = a | b ^ c | d;
  wire [1:0] x9 = a && b | c && d;
  wire [1:0] x10 = a || b && c || d;
  wire [1:0] x11 = a ? b || c : d ? e : f;

  // verilator lint_on WIDTH

  function [1:0] pow(input [1:0] x, input [1:0] y);
    casez ({
      x, y
    })
      4'b00_??: pow = 2'b00;
      4'b01_00: pow = 2'b01;
      4'b01_01: pow = 2'b01;
      4'b01_10: pow = 2'b01;
      4'b01_11: pow = 2'b01;
      4'b10_00: pow = 2'b01;
      4'b10_01: pow = 2'b10;
      4'b10_10: pow = 2'b00;
      4'b10_11: pow = 2'b00;
      4'b11_00: pow = 2'b01;
      4'b11_01: pow = 2'b11;
      4'b11_10: pow = 2'b01;
      4'b11_11: pow = 2'b11;
    endcase
  endfunction

  // Aggregate outputs into a single result vector
  // verilog_format: off
  wire [63:0] result = {12'h0,
                   x11,x10,x9,x8,x7,x6,x5,x4,x3,x2,x1,
                   o15,o14,o13,o12,o11,o10,o9,o8,o7,o6,o5,o4,o3,o2,o1};
  // verilog_format: on

  // Test loop
  always @(posedge clk) begin
`ifdef TEST_VERBOSE
    $write("[%0t] cyc==%0d crc=%x result=%x ", $time, cyc, crc, result);
    $write(" %b", o1);
    $write(" %b", o2);
    $write(" %b", o3);
    $write(" %b", o4);
    $write(" %b", o5);
    $write(" %b", o6);
    $write(" %b", o7);
    $write(" %b", o8);
    $write(" %b", o9);
    $write(" %b", o10);
    $write(" %b", o11);
    $write(" %b", o12);
    $write(" %b", o13);
    $write(" %b", o14);
    $write(" %b", o15);
    // Now cross each pair of groups
    $write(" %b", x1);
    $write(" %b", x2);
    $write(" %b", x3);
    $write(" %b", x4);
    $write(" %b", x5);
    $write(" %b", x6);
    $write(" %b", x7);
    $write(" %b", x8);
    $write(" %b", x9);
    $write(" %b", x10);
    $write(" %b", x11);
    $write("\n");
`endif
    cyc <= cyc + 1;
    crc <= {crc[62:0], crc[63] ^ crc[2] ^ crc[0]};
    sum <= result ^ {sum[62:0], sum[63] ^ sum[2] ^ sum[0]};
    if (cyc == 0) begin
      // Setup
      crc <= 64'h5aef0c8d_d70a4497;
      sum <= 64'h0;
    end
    else if (cyc < 10) begin
      sum <= 64'h0;
    end
    else if (cyc < 90) begin
    end
    else if (cyc == 99) begin
      $write("[%0t] cyc==%0d crc=%x sum=%x\n", $time, cyc, crc, sum);
      if (crc !== 64'hc77bb9b3784ea091) $stop;
      // What checksum will we end up with (above print should match)
      `define EXPECTED_SUM 64'h2756ea365ec7520e
      if (sum !== `EXPECTED_SUM) $stop;
      $write("*-* All Finished *-*\n");
      $finish;
    end
  end

endmodule