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			77 lines
		
	
	
	
		
			2.2 KiB
		
	
	
	
		
			Systemverilog
		
	
	
	
	
	
			
		
		
	
	
			77 lines
		
	
	
	
		
			2.2 KiB
		
	
	
	
		
			Systemverilog
		
	
	
	
	
	
`default_nettype none
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module evil;
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    parameter HI = 3;
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    parameter LO = 0;
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    parameter SPAN = 1;
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    parameter [HI:LO] A_VAL = 4'b0110;
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    parameter [HI:LO] B_VAL = 4'b1100;
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    parameter [2:0] SWAPS = 0;
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    localparam D_LEFT  = !(SWAPS[0]) ? HI : LO;
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    localparam D_RIGHT =  (SWAPS[0]) ? HI : LO;
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    localparam E_LEFT  = !(SWAPS[1]) ? HI : LO;
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    localparam E_RIGHT =  (SWAPS[1]) ? HI : LO;
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    localparam F_LEFT  = !(SWAPS[2]) ? HI : LO;
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    localparam F_RIGHT =  (SWAPS[2]) ? HI : LO;
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    localparam [HI:LO] A_CONST = A_VAL;
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    localparam [HI:LO] B_CONST = B_VAL;
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    localparam [HI:LO] C_CONST = F(A_CONST, B_CONST);
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    reg [HI:LO] C_WIRE, C_FUNC;
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    always @* begin
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        assert (C_CONST == C_WIRE);
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        assert (C_CONST == C_FUNC);
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    end
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    initial begin : blk
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        reg [HI:LO] A_WIRE;
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        reg [HI:LO] B_WIRE;
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        reg [D_LEFT:D_RIGHT] D;
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        reg [E_LEFT:E_RIGHT] E;
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        reg [F_LEFT:F_RIGHT] F_WIRE;
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        reg [31:0] i;
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        A_WIRE = A_VAL;
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        B_WIRE = B_VAL;
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        D = A_WIRE;
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        E = B_WIRE;
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        F_WIRE = 0;
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        for (i = LO; i + SPAN < HI; i = i + SPAN)
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            if (SPAN == 1)
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                F_WIRE[i] = D[i] && E[i];
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            else
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                F_WIRE[i+:SPAN] = D[i+:SPAN] && E[i+:SPAN];
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        C_WIRE = F_WIRE;
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        C_FUNC = F(A_WIRE, B_WIRE);
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    end
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    function automatic [F_LEFT:F_RIGHT] F(
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        input [D_LEFT:D_RIGHT] D,
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        input [E_LEFT:E_RIGHT] E);
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        reg [31:0] i;
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        F = 0;
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        for (i = LO; i + SPAN < HI; i = i + SPAN)
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            if (SPAN == 1)
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                F[i] = D[i] && E[i];
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            else
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                F[i+:SPAN] = D[i+:SPAN] && E[i+:SPAN];
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    endfunction
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endmodule
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module top;
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    for (genvar hi = 0; hi < 3; hi++)
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    for (genvar lo = 0; lo <= hi; lo++)
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    for (genvar span = 1; span <= hi - lo + 1; span++)
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    for (genvar a_val = 0; a_val < 2 ** (hi - lo + 1); a_val++)
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    for (genvar b_val = 0; b_val < 2 ** (hi - lo + 1); b_val++)
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    for (genvar swaps = 0; swaps < 2 ** 3; swaps++)
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        evil #(
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            .HI(hi),
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            .LO(lo),
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            .SPAN(span),
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            .A_VAL(a_val),
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            .B_VAL(b_val),
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            .SWAPS(swaps)
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        ) e();
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endmodule
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