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198fb2a | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 | module microgpt_categorical_sampler #(
parameter integer VOCAB_SIZE = 27
) (
input wire clk,
input wire resetn,
input wire start,
input wire [15:0] temperature_q8_8,
input wire [31:0] rng_state,
input wire [7:0] argmax_token,
input wire signed [15:0] top_logit_q12,
input wire signed [(VOCAB_SIZE*16)-1:0] logits_flat,
output reg busy,
output reg done,
output reg [7:0] next_token
);
localparam [3:0]
ST_IDLE = 4'd0,
ST_SUM = 4'd1,
ST_SUM_WEIGHT = 4'd2,
ST_SUM_ACC = 4'd3,
ST_MIX = 4'd4,
ST_SCALE = 4'd5,
ST_CUT = 4'd6,
ST_PICK = 4'd7,
ST_DONE = 4'd8;
reg [3:0] state_reg;
reg [6:0] row_reg;
reg [6:0] sum_row_reg;
reg [31:0] weight_sum_reg;
reg [31:0] cut_reg;
reg [31:0] acc_reg;
reg [31:0] mixed_rng_reg;
reg [63:0] scaled_cut_reg;
reg [7:0] choice_reg;
reg found_reg;
reg [31:0] sample_weight [0:VOCAB_SIZE-1];
reg [31:0] weight_pipe_reg;
reg [7:0] fine_index_reg;
reg delta_nonneg_reg;
reg sum_last_reg;
reg signed [31:0] delta_tmp;
reg [31:0] weight_tmp;
reg [31:0] sum_tmp;
reg [31:0] acc_tmp;
reg [7:0] choice_tmp;
reg found_tmp;
reg [5:0] coarse_index_tmp;
reg [1:0] frac_index_tmp;
reg [31:0] w0_tmp;
reg [31:0] w1_tmp;
reg [31:0] diff_tmp;
integer i;
wire signed [15:0] current_logit =
logits_flat[(row_reg * 16) +: 16];
function automatic signed [31:0] apply_temperature_delta;
input signed [31:0] delta_q12;
input [15:0] temp_q8_8;
begin
apply_temperature_delta = delta_q12;
if (temp_q8_8 <= 16'd128)
apply_temperature_delta = delta_q12 <<< 1;
else if (temp_q8_8 > 16'd256 && temp_q8_8 <= 16'd512)
apply_temperature_delta = delta_q12 >>> 1;
else if (temp_q8_8 > 16'd512)
apply_temperature_delta = delta_q12 >>> 2;
end
endfunction
function automatic [31:0] exp_neg_coarse_q12;
input [5:0] index;
begin
case (index)
6'd0: exp_neg_coarse_q12 = 32'd4096;
6'd1: exp_neg_coarse_q12 = 32'd3189;
6'd2: exp_neg_coarse_q12 = 32'd2484;
6'd3: exp_neg_coarse_q12 = 32'd1935;
6'd4: exp_neg_coarse_q12 = 32'd1507;
6'd5: exp_neg_coarse_q12 = 32'd1174;
6'd6: exp_neg_coarse_q12 = 32'd914;
6'd7: exp_neg_coarse_q12 = 32'd712;
6'd8: exp_neg_coarse_q12 = 32'd555;
6'd9: exp_neg_coarse_q12 = 32'd432;
6'd10: exp_neg_coarse_q12 = 32'd337;
6'd11: exp_neg_coarse_q12 = 32'd262;
6'd12: exp_neg_coarse_q12 = 32'd204;
6'd13: exp_neg_coarse_q12 = 32'd159;
6'd14: exp_neg_coarse_q12 = 32'd124;
6'd15: exp_neg_coarse_q12 = 32'd97;
6'd16: exp_neg_coarse_q12 = 32'd75;
6'd17: exp_neg_coarse_q12 = 32'd59;
6'd18: exp_neg_coarse_q12 = 32'd46;
6'd19: exp_neg_coarse_q12 = 32'd36;
6'd20: exp_neg_coarse_q12 = 32'd28;
6'd21: exp_neg_coarse_q12 = 32'd22;
6'd22: exp_neg_coarse_q12 = 32'd17;
6'd23: exp_neg_coarse_q12 = 32'd13;
6'd24: exp_neg_coarse_q12 = 32'd10;
6'd25: exp_neg_coarse_q12 = 32'd8;
6'd26: exp_neg_coarse_q12 = 32'd6;
6'd27: exp_neg_coarse_q12 = 32'd5;
6'd28: exp_neg_coarse_q12 = 32'd4;
6'd29: exp_neg_coarse_q12 = 32'd3;
6'd30: exp_neg_coarse_q12 = 32'd2;
default: exp_neg_coarse_q12 = 32'd1;
endcase
end
endfunction
function automatic [31:0] exp_neg_sample_q12;
input signed [31:0] delta_q12;
reg [7:0] fine_index;
reg [5:0] coarse_index;
reg [1:0] frac_index;
reg [31:0] w0;
reg [31:0] w1;
reg [31:0] diff;
begin
if (delta_q12 >= 0) begin
exp_neg_sample_q12 = 32'd4096;
end else begin
fine_index = ((-delta_q12) + 32'sd127) >>> 8;
coarse_index = fine_index[7:2];
frac_index = fine_index[1:0];
w0 = exp_neg_coarse_q12(coarse_index);
w1 = exp_neg_coarse_q12(coarse_index + 6'd1);
diff = w0 - w1;
exp_neg_sample_q12 = w0 - ((diff * {30'd0, frac_index}) >>> 2);
if (exp_neg_sample_q12 == 32'd0)
exp_neg_sample_q12 = 32'd1;
end
end
endfunction
always @(posedge clk) begin
if (!resetn) begin
state_reg <= ST_IDLE;
row_reg <= 7'd0;
sum_row_reg <= 7'd0;
weight_sum_reg <= 32'd0;
cut_reg <= 32'd0;
acc_reg <= 32'd0;
mixed_rng_reg <= 32'd0;
scaled_cut_reg <= 64'd0;
choice_reg <= 8'd0;
found_reg <= 1'b0;
weight_pipe_reg <= 32'd0;
fine_index_reg <= 8'd0;
delta_nonneg_reg <= 1'b0;
sum_last_reg <= 1'b0;
next_token <= 8'd0;
busy <= 1'b0;
done <= 1'b0;
for (i = 0; i < VOCAB_SIZE; i = i + 1)
sample_weight[i] <= 32'd0;
end else begin
done <= 1'b0;
case (state_reg)
ST_IDLE: begin
busy <= 1'b0;
if (start) begin
row_reg <= 7'd0;
sum_row_reg <= 7'd0;
weight_sum_reg <= 32'd0;
cut_reg <= 32'd0;
acc_reg <= 32'd0;
choice_reg <= argmax_token;
found_reg <= 1'b0;
weight_pipe_reg <= 32'd0;
fine_index_reg <= 8'd0;
delta_nonneg_reg <= 1'b0;
sum_last_reg <= 1'b0;
busy <= 1'b1;
state_reg <= ST_SUM;
end
end
ST_SUM: begin
delta_tmp = apply_temperature_delta(
$signed(current_logit) - $signed(top_logit_q12),
temperature_q8_8
);
sum_row_reg <= row_reg;
sum_last_reg <= (row_reg == VOCAB_SIZE - 1);
if (delta_tmp >= 0) begin
delta_nonneg_reg <= 1'b1;
fine_index_reg <= 8'd0;
end else begin
delta_nonneg_reg <= 1'b0;
fine_index_reg <= ((-delta_tmp) + 32'sd127) >>> 8;
end
state_reg <= ST_SUM_WEIGHT;
end
ST_SUM_WEIGHT: begin
if (delta_nonneg_reg) begin
weight_pipe_reg <= 32'd4096;
end else begin
coarse_index_tmp = fine_index_reg[7:2];
frac_index_tmp = fine_index_reg[1:0];
w0_tmp = exp_neg_coarse_q12(coarse_index_tmp);
w1_tmp = exp_neg_coarse_q12(coarse_index_tmp + 6'd1);
diff_tmp = w0_tmp - w1_tmp;
weight_pipe_reg <= w0_tmp - ((diff_tmp * {30'd0, frac_index_tmp}) >>> 2);
if ((w0_tmp - ((diff_tmp * {30'd0, frac_index_tmp}) >>> 2)) == 32'd0)
weight_pipe_reg <= 32'd1;
end
state_reg <= ST_SUM_ACC;
end
ST_SUM_ACC: begin
weight_tmp = weight_pipe_reg;
sum_tmp = weight_sum_reg + weight_tmp;
sample_weight[sum_row_reg] <= weight_tmp;
weight_sum_reg <= sum_tmp;
if (sum_last_reg) begin
if (sum_tmp == 32'd0)
weight_sum_reg <= 32'd1;
row_reg <= 7'd0;
state_reg <= ST_MIX;
end else begin
row_reg <= sum_row_reg + 7'd1;
state_reg <= ST_SUM;
end
end
ST_MIX: begin
mixed_rng_reg <= rng_state * 32'h000149FB;
state_reg <= ST_SCALE;
end
ST_SCALE: begin
scaled_cut_reg <= {40'd0, mixed_rng_reg[31:8]} * {32'd0, weight_sum_reg};
state_reg <= ST_CUT;
end
ST_CUT: begin
cut_reg <= scaled_cut_reg[55:24];
if (scaled_cut_reg[55:24] >= weight_sum_reg)
cut_reg <= weight_sum_reg - 32'd1;
acc_reg <= 32'd0;
choice_reg <= argmax_token;
found_reg <= 1'b0;
row_reg <= 7'd0;
state_reg <= ST_PICK;
end
ST_PICK: begin
weight_tmp = sample_weight[row_reg];
acc_tmp = acc_reg + weight_tmp;
choice_tmp = choice_reg;
found_tmp = found_reg;
if (!found_tmp && (acc_tmp > cut_reg)) begin
choice_tmp = {1'b0, row_reg};
found_tmp = 1'b1;
end
acc_reg <= acc_tmp;
choice_reg <= choice_tmp;
found_reg <= found_tmp;
if (row_reg == VOCAB_SIZE - 1) begin
next_token <= choice_tmp;
state_reg <= ST_DONE;
end else begin
row_reg <= row_reg + 7'd1;
end
end
ST_DONE: begin
busy <= 1'b0;
done <= 1'b1;
state_reg <= ST_IDLE;
end
default: begin
state_reg <= ST_IDLE;
busy <= 1'b0;
end
endcase
end
end
endmodule
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