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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 | library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
library work;
use work.helpers.all;
entity bit_counter is
port (
clk : in std_logic;
rs : in std_ulogic_vector(63 downto 0);
stall : in std_ulogic;
count_right : in std_ulogic;
do_popcnt : in std_ulogic;
is_32bit : in std_ulogic;
datalen : in std_ulogic_vector(3 downto 0);
result : out std_ulogic_vector(63 downto 0)
);
end entity bit_counter;
architecture behaviour of bit_counter is
-- signals for count-leading/trailing-zeroes
signal inp : std_ulogic_vector(63 downto 0);
signal inp_r : std_ulogic_vector(63 downto 0);
signal sum : std_ulogic_vector(64 downto 0);
signal sum_r : std_ulogic_vector(64 downto 0);
signal onehot : std_ulogic_vector(63 downto 0);
signal edge : std_ulogic_vector(63 downto 0);
signal bitnum : std_ulogic_vector(5 downto 0);
signal cntz : std_ulogic_vector(63 downto 0);
-- signals for popcnt
signal dlen_r : std_ulogic_vector(3 downto 0);
signal pcnt_r : std_ulogic;
subtype twobit is unsigned(1 downto 0);
type twobit32 is array(0 to 31) of twobit;
signal pc2 : twobit32;
subtype threebit is unsigned(2 downto 0);
type threebit16 is array(0 to 15) of threebit;
signal pc4 : threebit16;
subtype fourbit is unsigned(3 downto 0);
type fourbit8 is array(0 to 7) of fourbit;
signal pc8 : fourbit8;
signal pc8_r : fourbit8;
subtype fivebit is unsigned(4 downto 0);
type fivebit4 is array(0 to 3) of fivebit;
signal pc16 : fivebit4;
signal pc16_r : fivebit4;
subtype sixbit is unsigned(5 downto 0);
type sixbit2 is array(0 to 1) of sixbit;
signal pc32 : sixbit2;
signal popcnt : std_ulogic_vector(63 downto 0);
begin
countzero_r: process(clk)
begin
if rising_edge(clk) then
if stall = '0' then
inp_r <= inp;
sum_r <= sum;
end if;
end if;
end process;
countzero: process(all)
variable bitnum_e, bitnum_o : std_ulogic_vector(5 downto 0);
begin
if is_32bit = '0' then
if count_right = '0' then
inp <= bit_reverse(rs);
else
inp <= rs;
end if;
else
inp(63 downto 32) <= x"FFFFFFFF";
if count_right = '0' then
inp(31 downto 0) <= bit_reverse(rs(31 downto 0));
else
inp(31 downto 0) <= rs(31 downto 0);
end if;
end if;
sum <= std_ulogic_vector(unsigned('0' & not inp) + 1);
-- The following occurs after a clock edge
edge <= sum_r(63 downto 0) or inp_r;
bitnum_e := edgelocation(edge, 6);
onehot <= sum_r(63 downto 0) and inp_r;
bitnum_o := bit_number(onehot);
bitnum(5 downto 2) <= bitnum_e(5 downto 2);
bitnum(1 downto 0) <= bitnum_o(1 downto 0);
cntz <= 57x"0" & sum_r(64) & bitnum;
end process;
popcnt_r: process(clk)
begin
if rising_edge(clk) then
if stall = '0' then
for i in 0 to 7 loop
pc8_r(i) <= pc8(i);
end loop;
for i in 0 to 3 loop
pc16_r(i) <= pc16(i);
end loop;
dlen_r <= datalen;
pcnt_r <= do_popcnt;
end if;
end if;
end process;
popcnt_a: process(all)
begin
for i in 0 to 31 loop
pc2(i) <= unsigned("0" & rs(i * 2 downto i * 2)) + unsigned("0" & rs(i * 2 + 1 downto i * 2 + 1));
end loop;
for i in 0 to 15 loop
pc4(i) <= ('0' & pc2(i * 2)) + ('0' & pc2(i * 2 + 1));
end loop;
for i in 0 to 7 loop
pc8(i) <= ('0' & pc4(i * 2)) + ('0' & pc4(i * 2 + 1));
end loop;
for i in 0 to 3 loop
pc16(i) <= ('0' & pc8(i * 2)) + ('0' & pc8(i * 2 + 1));
end loop;
-- after a clock edge
for i in 0 to 1 loop
pc32(i) <= ('0' & pc16_r(i * 2)) + ('0' & pc16_r(i * 2 + 1));
end loop;
popcnt <= (others => '0');
if dlen_r(3 downto 2) = "00" then
-- popcntb
for i in 0 to 7 loop
popcnt(i * 8 + 3 downto i * 8) <= std_ulogic_vector(pc8_r(i));
end loop;
elsif dlen_r(3) = '0' then
-- popcntw
for i in 0 to 1 loop
popcnt(i * 32 + 5 downto i * 32) <= std_ulogic_vector(pc32(i));
end loop;
else
popcnt(6 downto 0) <= std_ulogic_vector(('0' & pc32(0)) + ('0' & pc32(1)));
end if;
end process;
result <= cntz when pcnt_r = '0' else popcnt;
end behaviour;
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