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import fp_wire::*;
module fp_rnd (
input fp_rnd_in_type fp_rnd_i,
output fp_rnd_out_type fp_rnd_o
);
logic sig;
logic [13:0] expo;
logic [53:0] mant;
logic [1:0] rema;
logic [1:0] fmt;
logic [2:0] rm;
logic [2:0] grs;
logic snan;
logic qnan;
logic dbz;
logic infs;
logic zero;
logic diff;
logic odd;
logic rndup;
logic rnddn;
logic shift;
logic [63:0] result;
logic [4:0] flags;
always_comb begin
sig = fp_rnd_i.sig;
expo = fp_rnd_i.expo;
mant = fp_rnd_i.mant;
rema = fp_rnd_i.rema;
fmt = fp_rnd_i.fmt;
rm = fp_rnd_i.rm;
grs = fp_rnd_i.grs;
snan = fp_rnd_i.snan;
qnan = fp_rnd_i.qnan;
dbz = fp_rnd_i.dbz;
infs = fp_rnd_i.infs;
zero = fp_rnd_i.zero;
diff = fp_rnd_i.diff;
result = 0;
flags = 0;
odd = mant[0] | |grs[1:0] | (rema == 1);
flags[0] = (rema != 0) | |grs;
rndup = 0;
rnddn = 0;
if (rm == 0) begin //rne
if (grs[2] & odd) begin
rndup = 1;
end
end else if (rm == 1) begin //rtz
rnddn = 1;
end else if (rm == 2) begin //rdn
if (sig & flags[0]) begin
rndup = 1;
end else if (~sig & zero & diff) begin
sig = ~sig;
end else if (~sig) begin
rnddn = 1;
end
end else if (rm == 3) begin //rup
if (~sig & flags[0]) begin
rndup = 1;
end else if (sig) begin
rnddn = 1;
end
end else if (rm == 4) begin //rmm
if (grs[2] & flags[0]) begin
rndup = 1;
end
end
//if (expo == 0) begin
// flags[1] = flags[0];
//end
mant = mant + {53'h0, rndup};
if (rndup == 1) begin
if (fmt == 0) begin
if (expo == 0) begin
if (mant[23]) begin
expo = 1;
end
end
end else if (fmt == 1) begin
if (expo == 0) begin
if (mant[52]) begin
expo = 1;
end
end
end
end
if (rnddn == 1) begin
if (fmt == 0) begin
if (expo >= 255) begin
expo = 254;
mant = {31'b0, {23{1'b1}}};
flags = 5'b00101;
end
end else if (fmt == 1) begin
if (expo >= 2047) begin
expo = 2046;
mant = {2'b0, {52{1'b1}}};
flags = 5'b00101;
end
end
end
shift = 0;
if (fmt == 0) begin
if (mant[24]) begin
shift = 1;
end
end else if (fmt == 1) begin
if (mant[53]) begin
shift = 1;
end
end
expo = expo + {13'h0, shift};
mant = mant >> shift;
if (expo == 0) begin
flags[1] = flags[0];
end
if (rndup == 1) begin
if (expo == 1) begin
if (fmt == 0 && |mant[22:0] == 0) begin
flags[1] = rm == 2 || rm == 3 ? ((grs == 1) | (grs == 2) | (grs == 3) | (grs == 4)) : ((grs == 4) | (grs == 5));
end else if (fmt == 1 && |mant[51:0] == 0) begin
flags[1] = rm == 2 || rm == 3 ? ((grs == 1) | (grs == 2) | (grs == 3) | (grs == 4)) : ((grs == 4) | (grs == 5));
end
end
end
if (snan) begin
flags = 5'b10000;
end else if (qnan) begin
flags = 5'b00000;
end else if (dbz) begin
flags = 5'b01000;
end else if (infs) begin
flags = 5'b00000;
end else if (zero) begin
flags = 5'b00000;
end
if (fmt == 0) begin
if (snan | qnan) begin
result = {32'h00000000, 1'h0, 8'hFF, 23'h400000};
end else if (dbz | infs) begin
result = {32'h00000000, sig, 8'hFF, 23'h000000};
end else if (zero) begin
result = {32'h00000000, sig, 8'h00, 23'h000000};
end else if (expo == 0) begin
result = {32'h00000000, sig, 8'h00, mant[22:0]};
end else if ($signed(expo) > 254) begin
flags = 5'b00101;
result = {32'h00000000, sig, 8'hFF, 23'h000000};
end else begin
result = {32'h00000000, sig, expo[7:0], mant[22:0]};
end
end else if (fmt == 1) begin
if (snan | qnan) begin
result = {1'h0, 11'h7FF, 52'h8000000000000};
end else if (dbz | infs) begin
result = {sig, 11'h7FF, 52'h0000000000000};
end else if (zero) begin
result = {sig, 11'h000, 52'h0000000000000};
end else if (expo == 0) begin
result = {sig, 11'h000, mant[51:0]};
end else if ($signed(expo) > 2046) begin
flags = 5'b00101;
result = {sig, 11'h7FF, 52'h0000000000000};
end else begin
result = {sig, expo[10:0], mant[51:0]};
end
end
fp_rnd_o.result = result;
fp_rnd_o.flags = flags;
end
endmodule
|
