library work;
package helpers is
- function fls_32 (val: std_ulogic_vector(31 downto 0)) return integer;
- function ffs_32 (val: std_ulogic_vector(31 downto 0)) return integer;
+ function fls_32 (val: std_ulogic_vector(31 downto 0)) return integer;
+ function ffs_32 (val: std_ulogic_vector(31 downto 0)) return integer;
- function fls_64 (val: std_ulogic_vector(63 downto 0)) return integer;
- function ffs_64 (val: std_ulogic_vector(63 downto 0)) return integer;
+ function fls_64 (val: std_ulogic_vector(63 downto 0)) return integer;
+ function ffs_64 (val: std_ulogic_vector(63 downto 0)) return integer;
- function popcnt8(val: std_ulogic_vector(7 downto 0)) return std_ulogic_vector;
- function popcnt32(val: std_ulogic_vector(31 downto 0)) return std_ulogic_vector;
- function popcnt64(val: std_ulogic_vector(63 downto 0)) return std_ulogic_vector;
+ function popcnt8(val: std_ulogic_vector(7 downto 0)) return std_ulogic_vector;
+ function popcnt32(val: std_ulogic_vector(31 downto 0)) return std_ulogic_vector;
+ function popcnt64(val: std_ulogic_vector(63 downto 0)) return std_ulogic_vector;
- function cmp_one_byte(a, b: std_ulogic_vector(7 downto 0)) return std_ulogic_vector;
+ function cmp_one_byte(a, b: std_ulogic_vector(7 downto 0)) return std_ulogic_vector;
- function ppc_signed_compare(a, b: signed(63 downto 0)) return std_ulogic_vector;
- function ppc_unsigned_compare(a, b: unsigned(63 downto 0)) return std_ulogic_vector;
+ function ppc_signed_compare(a, b: signed(63 downto 0); so: std_ulogic) return std_ulogic_vector;
+ function ppc_unsigned_compare(a, b: unsigned(63 downto 0); so: std_ulogic) return std_ulogic_vector;
- function ra_or_zero(ra: std_ulogic_vector(63 downto 0); reg: std_ulogic_vector(4 downto 0)) return std_ulogic_vector;
+ function ra_or_zero(ra: std_ulogic_vector(63 downto 0); reg: std_ulogic_vector(4 downto 0)) return std_ulogic_vector;
- function byte_reverse(val: std_ulogic_vector(63 downto 0); size: integer) return std_ulogic_vector;
+ function byte_reverse(val: std_ulogic_vector(63 downto 0); size: integer) return std_ulogic_vector;
- function sign_extend(val: std_ulogic_vector(63 downto 0); size: natural) return std_ulogic_vector;
+ function sign_extend(val: std_ulogic_vector(63 downto 0); size: natural) return std_ulogic_vector;
+
+ function bit_reverse(a: std_ulogic_vector) return std_ulogic_vector;
+ function bit_number(a: std_ulogic_vector(63 downto 0)) return std_ulogic_vector;
+ function count_left_zeroes(val: std_ulogic_vector) return std_ulogic_vector;
end package helpers;
package body helpers is
- function fls_32 (val: std_ulogic_vector(31 downto 0)) return integer is
- variable ret: integer;
- begin
- ret := 32;
- for i in val'range loop
- if val(i) = '1' then
- ret := 31 - i;
- exit;
- end if;
- end loop;
-
- return ret;
- end;
-
- function ffs_32 (val: std_ulogic_vector(31 downto 0)) return integer is
- variable ret: integer;
- begin
- ret := 32;
- for i in val'reverse_range loop
- if val(i) = '1' then
- ret := i;
- exit;
- end if;
- end loop;
-
- return ret;
- end;
-
- function fls_64 (val: std_ulogic_vector(63 downto 0)) return integer is
- variable ret: integer;
- begin
- ret := 64;
- for i in val'range loop
- if val(i) = '1' then
- ret := 63 - i;
- exit;
- end if;
- end loop;
-
- return ret;
- end;
-
- function ffs_64 (val: std_ulogic_vector(63 downto 0)) return integer is
- variable ret: integer;
- begin
- ret := 64;
- for i in val'reverse_range loop
- if val(i) = '1' then
- ret := i;
- exit;
- end if;
- end loop;
-
- return ret;
- end;
-
- function popcnt8(val: std_ulogic_vector(7 downto 0)) return std_ulogic_vector is
- variable ret: unsigned(3 downto 0) := (others => '0');
- begin
- for i in val'range loop
- ret := ret + ("000" & val(i));
- end loop;
-
- return std_ulogic_vector(resize(ret, val'length));
- end;
-
- function popcnt32(val: std_ulogic_vector(31 downto 0)) return std_ulogic_vector is
- variable ret: unsigned(5 downto 0) := (others => '0');
- begin
- for i in val'range loop
- ret := ret + ("00000" & val(i));
- end loop;
-
- return std_ulogic_vector(resize(ret, val'length));
- end;
-
- function popcnt64(val: std_ulogic_vector(63 downto 0)) return std_ulogic_vector is
- variable ret: unsigned(6 downto 0) := (others => '0');
- begin
- for i in val'range loop
- ret := ret + ("000000" & val(i));
- end loop;
-
- return std_ulogic_vector(resize(ret, val'length));
- end;
-
- function cmp_one_byte(a, b: std_ulogic_vector(7 downto 0)) return std_ulogic_vector is
- variable ret: std_ulogic_vector(7 downto 0);
- begin
- if a = b then
- ret := x"ff";
- else
- ret := x"00";
- end if;
-
- return ret;
- end;
-
- function ppc_signed_compare(a, b: signed(63 downto 0)) return std_ulogic_vector is
- variable ret: std_ulogic_vector(3 downto 0);
- begin
- if a < b then
- ret := "1000";
- elsif a > b then
- ret := "0100";
- else
- ret := "0010";
- end if;
-
- return ret;
- end;
-
- function ppc_unsigned_compare(a, b: unsigned(63 downto 0)) return std_ulogic_vector is
- variable ret: std_ulogic_vector(3 downto 0);
- begin
- if a < b then
- ret := "1000";
- elsif a > b then
- ret := "0100";
- else
- ret := "0010";
- end if;
-
- return ret;
- end;
-
- function ra_or_zero(ra: std_ulogic_vector(63 downto 0); reg: std_ulogic_vector(4 downto 0)) return std_ulogic_vector is
- begin
- if to_integer(unsigned(reg)) = 0 then
- return x"0000000000000000";
- else
- return ra;
- end if;
- end;
-
- function byte_reverse(val: std_ulogic_vector(63 downto 0); size: integer) return std_ulogic_vector is
- variable ret : std_ulogic_vector(63 downto 0) := (others => '0');
- begin
- -- Vivado doesn't support non constant vector slices, so we have to code
- -- each of these.
- case_0: case size is
- when 2 =>
- for_2 : for k in 0 to 1 loop
- ret(((8*k)+7) downto (8*k)) := val((8*(1-k)+7) downto (8*(1-k)));
- end loop;
- when 4 =>
- for_4 : for k in 0 to 3 loop
- ret(((8*k)+7) downto (8*k)) := val((8*(3-k)+7) downto (8*(3-k)));
- end loop;
- when 8 =>
- for_8 : for k in 0 to 7 loop
- ret(((8*k)+7) downto (8*k)) := val((8*(7-k)+7) downto (8*(7-k)));
- end loop;
- when others =>
- report "bad byte reverse length " & integer'image(size) severity failure;
- end case;
-
- return ret;
- end;
-
- function sign_extend(val: std_ulogic_vector(63 downto 0); size: natural) return std_ulogic_vector is
- variable ret : signed(63 downto 0) := (others => '0');
- variable upper : integer := 0;
- begin
- case_0: case size is
- when 2 =>
- upper := 15;
- when 4 =>
- upper := 31;
- when 8 =>
- upper := 63;
- when others =>
- report "bad byte reverse length " & integer'image(size) severity failure;
- end case;
-
- ret := resize(signed(val(upper downto 0)), 64);
- return std_ulogic_vector(ret);
- end;
+ function fls_32 (val: std_ulogic_vector(31 downto 0)) return integer is
+ variable ret: integer;
+ begin
+ ret := 32;
+ for i in val'range loop
+ if val(i) = '1' then
+ ret := 31 - i;
+ exit;
+ end if;
+ end loop;
+
+ return ret;
+ end;
+
+ function ffs_32 (val: std_ulogic_vector(31 downto 0)) return integer is
+ variable ret: integer;
+ begin
+ ret := 32;
+ for i in val'reverse_range loop
+ if val(i) = '1' then
+ ret := i;
+ exit;
+ end if;
+ end loop;
+
+ return ret;
+ end;
+
+ function fls_64 (val: std_ulogic_vector(63 downto 0)) return integer is
+ variable ret: integer;
+ begin
+ ret := 64;
+ for i in val'range loop
+ if val(i) = '1' then
+ ret := 63 - i;
+ exit;
+ end if;
+ end loop;
+
+ return ret;
+ end;
+
+ function ffs_64 (val: std_ulogic_vector(63 downto 0)) return integer is
+ variable ret: integer;
+ begin
+ ret := 64;
+ for i in val'reverse_range loop
+ if val(i) = '1' then
+ ret := i;
+ exit;
+ end if;
+ end loop;
+
+ return ret;
+ end;
+
+ function popcnt8(val: std_ulogic_vector(7 downto 0)) return std_ulogic_vector is
+ variable ret: unsigned(3 downto 0) := (others => '0');
+ begin
+ for i in val'range loop
+ ret := ret + ("000" & val(i));
+ end loop;
+
+ return std_ulogic_vector(resize(ret, val'length));
+ end;
+
+ function popcnt32(val: std_ulogic_vector(31 downto 0)) return std_ulogic_vector is
+ variable ret: unsigned(5 downto 0) := (others => '0');
+ begin
+ for i in val'range loop
+ ret := ret + ("00000" & val(i));
+ end loop;
+
+ return std_ulogic_vector(resize(ret, val'length));
+ end;
+
+ function popcnt64(val: std_ulogic_vector(63 downto 0)) return std_ulogic_vector is
+ variable ret: unsigned(6 downto 0) := (others => '0');
+ begin
+ for i in val'range loop
+ ret := ret + ("000000" & val(i));
+ end loop;
+
+ return std_ulogic_vector(resize(ret, val'length));
+ end;
+
+ function cmp_one_byte(a, b: std_ulogic_vector(7 downto 0)) return std_ulogic_vector is
+ variable ret: std_ulogic_vector(7 downto 0);
+ begin
+ if a = b then
+ ret := x"ff";
+ else
+ ret := x"00";
+ end if;
+
+ return ret;
+ end;
+
+ function ppc_signed_compare(a, b: signed(63 downto 0); so: std_ulogic) return std_ulogic_vector is
+ variable ret: std_ulogic_vector(2 downto 0);
+ begin
+ if a < b then
+ ret := "100";
+ elsif a > b then
+ ret := "010";
+ else
+ ret := "001";
+ end if;
+
+ return ret & so;
+ end;
+
+ function ppc_unsigned_compare(a, b: unsigned(63 downto 0); so: std_ulogic) return std_ulogic_vector is
+ variable ret: std_ulogic_vector(2 downto 0);
+ begin
+ if a < b then
+ ret := "100";
+ elsif a > b then
+ ret := "010";
+ else
+ ret := "001";
+ end if;
+
+ return ret & so;
+ end;
+
+ function ra_or_zero(ra: std_ulogic_vector(63 downto 0); reg: std_ulogic_vector(4 downto 0)) return std_ulogic_vector is
+ begin
+ if to_integer(unsigned(reg)) = 0 then
+ return x"0000000000000000";
+ else
+ return ra;
+ end if;
+ end;
+
+ function byte_reverse(val: std_ulogic_vector(63 downto 0); size: integer) return std_ulogic_vector is
+ variable ret : std_ulogic_vector(63 downto 0) := (others => '0');
+ begin
+ -- Vivado doesn't support non constant vector slices, so we have to code
+ -- each of these.
+ case_0: case size is
+ when 2 =>
+ for_2 : for k in 0 to 1 loop
+ ret(((8*k)+7) downto (8*k)) := val((8*(1-k)+7) downto (8*(1-k)));
+ end loop;
+ when 4 =>
+ for_4 : for k in 0 to 3 loop
+ ret(((8*k)+7) downto (8*k)) := val((8*(3-k)+7) downto (8*(3-k)));
+ end loop;
+ when 8 =>
+ for_8 : for k in 0 to 7 loop
+ ret(((8*k)+7) downto (8*k)) := val((8*(7-k)+7) downto (8*(7-k)));
+ end loop;
+ when others =>
+ report "bad byte reverse length " & integer'image(size) severity failure;
+ end case;
+
+ return ret;
+ end;
+
+ function sign_extend(val: std_ulogic_vector(63 downto 0); size: natural) return std_ulogic_vector is
+ variable ret : signed(63 downto 0) := (others => '0');
+ variable upper : integer := 0;
+ begin
+ case_0: case size is
+ when 2 =>
+ ret := resize(signed(val(15 downto 0)), 64);
+ when 4 =>
+ ret := resize(signed(val(31 downto 0)), 64);
+ when 8 =>
+ ret := resize(signed(val(63 downto 0)), 64);
+ when others =>
+ report "bad byte reverse length " & integer'image(size) severity failure;
+ end case;
+
+ return std_ulogic_vector(ret);
+
+ end;
+
+ -- Reverse the order of bits in a word
+ function bit_reverse(a: std_ulogic_vector) return std_ulogic_vector is
+ variable ret: std_ulogic_vector(a'left downto a'right);
+ begin
+ for i in a'right to a'left loop
+ ret(a'left + a'right - i) := a(i);
+ end loop;
+ return ret;
+ end;
+
+ -- If there is only one bit set in a doubleword, return its bit number
+ -- (counting from the right). Each bit of the result is obtained by
+ -- ORing together 32 bits of the input:
+ -- bit 0 = a[1] or a[3] or a[5] or ...
+ -- bit 1 = a[2] or a[3] or a[6] or a[7] or ...
+ -- bit 2 = a[4..7] or a[12..15] or ...
+ -- bit 5 = a[32..63] ORed together
+ function bit_number(a: std_ulogic_vector(63 downto 0)) return std_ulogic_vector is
+ variable ret: std_ulogic_vector(5 downto 0);
+ variable stride: natural;
+ variable bit: std_ulogic;
+ variable k: natural;
+ begin
+ stride := 2;
+ for i in 0 to 5 loop
+ bit := '0';
+ for j in 0 to (64 / stride) - 1 loop
+ k := j * stride;
+ bit := bit or (or a(k + stride - 1 downto k + (stride / 2)));
+ end loop;
+ ret(i) := bit;
+ stride := stride * 2;
+ end loop;
+ return ret;
+ end;
+
+ -- Count leading zeroes operation
+ -- Assumes the value passed in is not zero (if it is, zero is returned)
+ function count_left_zeroes(val: std_ulogic_vector) return std_ulogic_vector is
+ variable rev: std_ulogic_vector(val'left downto val'right);
+ variable sum: std_ulogic_vector(val'left downto val'right);
+ variable onehot: std_ulogic_vector(val'left downto val'right);
+ begin
+ rev := bit_reverse(val);
+ sum := std_ulogic_vector(- signed(rev));
+ onehot := sum and rev;
+ return bit_number(std_ulogic_vector(resize(unsigned(onehot), 64)));
+ end;
end package body helpers;
projects / microwatt.git / blobdiff