crhelpers: Constraint "crnum" integer

This seems to save quite a few LUTs

Signed-off-by: Benjamin Herrenschmidt <>
Benjamin Herrenschmidt 5 years ago
parent 4437487ad0
commit da0bd89c43

@ -5,13 +5,16 @@ library work;
use work.common.all;

package crhelpers is
function fxm_to_num(fxm: std_ulogic_vector(7 downto 0)) return integer;
function num_to_fxm(num: integer) return std_ulogic_vector;
subtype crnum_t is integer range 0 to 7;
subtype crmask_t is std_ulogic_vector(7 downto 0);

function fxm_to_num(fxm: crmask_t) return crnum_t;
function num_to_fxm(num: crnum_t) return crmask_t;
end package crhelpers;

package body crhelpers is

function fxm_to_num(fxm: std_ulogic_vector(7 downto 0)) return integer is
function fxm_to_num(fxm: crmask_t) return crnum_t is
-- If multiple fields are set (undefined), match existing
-- hardware by returning the first one.
@ -27,7 +30,7 @@ package body crhelpers is
return 7;

function num_to_fxm(num: integer) return std_ulogic_vector is
function num_to_fxm(num: crnum_t) return crmask_t is
case num is
when 0 =>

@ -109,8 +109,8 @@ begin
variable newcrf : std_ulogic_vector(3 downto 0);
variable result_with_carry : std_ulogic_vector(64 downto 0);
variable result_en : integer;
variable crnum : integer;
variable scrnum : integer;
variable crnum : crnum_t;
variable scrnum : crnum_t;
variable lo, hi : integer;
variable sh, mb, me : std_ulogic_vector(5 downto 0);
variable sh32, mb32, me32 : std_ulogic_vector(4 downto 0);