verilator/test_regress/t/t_const_opt_or.v
2021-11-13 10:46:25 -05:00

112 lines
3.1 KiB
Systemverilog

// DESCRIPTION: Verilator: Verilog Test module
//
// This file ONLY is placed under the Creative Commons Public Domain, for
// any use, without warranty, 2020 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;
// Take CRC data and apply to testblock inputs
wire [31:0] in = crc[31:0];
/*AUTOWIRE*/
// Beginning of automatic wires (for undeclared instantiated-module outputs)
wire [31:0] rd0; // From test of Test.v
wire [31:0] rd1; // From test of Test.v
// End of automatics
wire rden0 = crc[0];
wire rden1 = crc[1];
wire [4:0] raddr0 = crc[20:16];
wire [4:0] raddr1 = crc[28:24];
Test test(/*AUTOINST*/
// Outputs
.rd0 (rd0[31:0]),
.rd1 (rd1[31:0]),
// Inputs
.clk (clk),
.raddr0 (raddr0[4:0]),
.raddr1 (raddr1[4:0]),
.rden0 (rden0),
.rden1 (rden1));
// Aggregate outputs into a single result vector
wire [63:0] result = {rd1, rd0};
// Test loop
always @ (posedge clk) begin
`ifdef TEST_VERBOSE
$write("[%0t] cyc==%0d crc=%x result=%x\n", $time, cyc, crc, result);
`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 <= '0;
end
else if (cyc < 10) begin
sum <= '0;
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'hdc97b141ac5d6d7d
if (sum !== `EXPECTED_SUM) $stop;
$write("*-* All Finished *-*\n");
$finish;
end
end
endmodule
module Test(/*AUTOARG*/
// Outputs
rd0, rd1,
// Inputs
clk, raddr0, raddr1, rden0, rden1
);
input clk;
input [4:0] raddr0;
input [4:0] raddr1;
input rden0;
input rden1;
output reg [31:0] rd0;
output reg [31:0] rd1;
reg [31:0] gpr [31:1];
initial begin
for (int j=1; j<32; j++ ) begin
gpr[j] = {8'(j), 8'(j), 8'(j), 8'(j)};
end
end
always_comb begin
rd0[31:0] = 32'b0;
rd1[31:0] = 32'b0;
// Future optimization:
// Multiple assignments to same variable with OR between them
// ASSIGN(a, OR(a, aq)), ASSIGN(a, OR(a, bq)) -> ASSIGN(a, OR(a, OR(aq, bq))
// Skip if we're not const'ing an entire module (IE doing only one assign, etc)
for (int j=1; j<32; j++ ) begin
rd0[31:0] |= ({32{rden0 & (raddr0[4:0]== 5'(j))}} & gpr[j][31:0]);
rd1[31:0] |= ({32{rden1 & (raddr1[4:0]== 5'(j))}} & gpr[j][31:0]);
end
end
endmodule