float_pkg_c.vhdl

something i got you may find this useful

    arg  : UNRESOLVED_float;            -- floating point input
    XMAP : STD_LOGIC := '0')
    return UNRESOLVED_float;

  function Is_X (arg    : UNRESOLVED_float) return BOOLEAN;
  function to_X01 (arg  : UNRESOLVED_float) return UNRESOLVED_float;
  function to_X01Z (arg : UNRESOLVED_float) return UNRESOLVED_float;
  function to_UX01 (arg : UNRESOLVED_float) return UNRESOLVED_float;

  -- These two procedures were copied out of the body because they proved
  -- very useful for vendor specific algorithm development
  -- Break_number converts a floating point number into it's parts
  -- Exponent is biased by -1

  procedure break_number (
    arg         : in  UNRESOLVED_float;
    denormalize : in  BOOLEAN := float_denormalize;
    check_error : in  BOOLEAN := float_check_error;
    fract       : out UNSIGNED;
    expon       : out SIGNED;  -- NOTE:  Add 1 to get the real exponent!
    sign        : out STD_ULOGIC);

  procedure break_number (
    arg         : in  UNRESOLVED_float;
    denormalize : in  BOOLEAN := float_denormalize;
    check_error : in  BOOLEAN := float_check_error;
    fract       : out ufixed;           -- a number between 1.0 and 2.0
    expon       : out SIGNED;  -- NOTE:  Add 1 to get the real exponent!
    sign        : out STD_ULOGIC);

  -- Normalize takes a fraction and and exponent and converts them into
  -- a floating point number.  Does the shifting and the rounding.
  -- Exponent is assumed to be biased by -1

  function normalize (
    fract                   : UNSIGNED;  -- fraction, unnormalized
    expon                   : SIGNED;   -- exponent - 1, normalized
    sign                    : STD_ULOGIC;         -- sign bit
    sticky                  : STD_ULOGIC := '0';  -- Sticky bit (rounding)
    constant exponent_width : NATURAL    := float_exponent_width;  -- size of output exponent
    constant fraction_width : NATURAL    := float_fraction_width;  -- size of output fraction
    constant round_style    : round_type := float_round_style;  -- rounding option
    constant denormalize    : BOOLEAN    := float_denormalize;  -- Use IEEE extended FP
    constant nguard         : NATURAL    := float_guard_bits)   -- guard bits
    return UNRESOLVED_float;

  -- Exponent is assumed to be biased by -1
  function normalize (
    fract                   : ufixed;   -- unsigned fixed point
    expon                   : SIGNED;   -- exponent - 1, normalized
    sign                    : STD_ULOGIC;         -- sign bit
    sticky                  : STD_ULOGIC := '0';  -- Sticky bit (rounding)
    constant exponent_width : NATURAL    := float_exponent_width;  -- size of output exponent
    constant fraction_width : NATURAL    := float_fraction_width;  -- size of output fraction
    constant round_style    : round_type := float_round_style;  -- rounding option
    constant denormalize    : BOOLEAN    := float_denormalize;  -- Use IEEE extended FP
    constant nguard         : NATURAL    := float_guard_bits)   -- guard bits
    return UNRESOLVED_float;

  function normalize (
    fract                : UNSIGNED;    -- unsigned
    expon                : SIGNED;      -- exponent - 1, normalized
    sign                 : STD_ULOGIC;  -- sign bit
    sticky               : STD_ULOGIC := '0';  -- Sticky bit (rounding)
    size_res             : UNRESOLVED_float;   -- used for sizing only
    constant round_style : round_type := float_round_style;  -- rounding option
    constant denormalize : BOOLEAN    := float_denormalize;  -- Use IEEE extended FP
    constant nguard      : NATURAL    := float_guard_bits)   -- guard bits
    return UNRESOLVED_float;

  -- Exponent is assumed to be biased by -1
  function normalize (
    fract                : ufixed;      -- unsigned fixed point
    expon                : SIGNED;      -- exponent - 1, normalized
    sign                 : STD_ULOGIC;  -- sign bit
    sticky               : STD_ULOGIC := '0';  -- Sticky bit (rounding)
    size_res             : UNRESOLVED_float;   -- used for sizing only
    constant round_style : round_type := float_round_style;  -- rounding option
    constant denormalize : BOOLEAN    := float_denormalize;  -- Use IEEE extended FP
    constant nguard      : NATURAL    := float_guard_bits)   -- guard bits
    return UNRESOLVED_float;

  -- overloaded versions
  function "+"   (l : UNRESOLVED_float; r : REAL)    return UNRESOLVED_float;
  function "+"   (l : REAL; r : UNRESOLVED_float)    return UNRESOLVED_float;
  function "+"   (l : UNRESOLVED_float; r : INTEGER) return UNRESOLVED_float;
  function "+"   (l : INTEGER; r : UNRESOLVED_float) return UNRESOLVED_float;
  function "-"   (l : UNRESOLVED_float; r : REAL)    return UNRESOLVED_float;
  function "-"   (l : REAL; r : UNRESOLVED_float)    return UNRESOLVED_float;
  function "-"   (l : UNRESOLVED_float; r : INTEGER) return UNRESOLVED_float;
  function "-"   (l : INTEGER; r : UNRESOLVED_float) return UNRESOLVED_float;
  function "*"   (l : UNRESOLVED_float; r : REAL)    return UNRESOLVED_float;
  function "*"   (l : REAL; r : UNRESOLVED_float)    return UNRESOLVED_float;
  function "*"   (l : UNRESOLVED_float; r : INTEGER) return UNRESOLVED_float;
  function "*"   (l : INTEGER; r : UNRESOLVED_float) return UNRESOLVED_float;
  function "/"   (l : UNRESOLVED_float; r : REAL)    return UNRESOLVED_float;
  function "/"   (l : REAL; r : UNRESOLVED_float)    return UNRESOLVED_float;
  function "/"   (l : UNRESOLVED_float; r : INTEGER) return UNRESOLVED_float;
  function "/"   (l : INTEGER; r : UNRESOLVED_float) return UNRESOLVED_float;
  function "rem" (l : UNRESOLVED_float; r : REAL)    return UNRESOLVED_float;
  function "rem" (l : REAL; r : UNRESOLVED_float)    return UNRESOLVED_float;
  function "rem" (l : UNRESOLVED_float; r : INTEGER) return UNRESOLVED_float;
  function "rem" (l : INTEGER; r : UNRESOLVED_float) return UNRESOLVED_float;
  function "mod" (l : UNRESOLVED_float; r : REAL)    return UNRESOLVED_float;
  function "mod" (l : REAL; r : UNRESOLVED_float)    return UNRESOLVED_float;
  function "mod" (l : UNRESOLVED_float; r : INTEGER) return UNRESOLVED_float;
  function "mod" (l : INTEGER; r : UNRESOLVED_float) return UNRESOLVED_float;

  -- overloaded compare functions
  function "="   (l : UNRESOLVED_float; r : REAL)    return BOOLEAN;
  function "/="  (l : UNRESOLVED_float; r : REAL)    return BOOLEAN;
  function ">="  (l : UNRESOLVED_float; r : REAL)    return BOOLEAN;
  function "<="  (l : UNRESOLVED_float; r : REAL)    return BOOLEAN;
  function ">"   (l : UNRESOLVED_float; r : REAL)    return BOOLEAN;
  function "<"   (l : UNRESOLVED_float; r : REAL)    return BOOLEAN;
  function "="   (l : REAL; r : UNRESOLVED_float)    return BOOLEAN;
  function "/="  (l : REAL; r : UNRESOLVED_float)    return BOOLEAN;
  function ">="  (l : REAL; r : UNRESOLVED_float)    return BOOLEAN;
  function "<="  (l : REAL; r : UNRESOLVED_float)    return BOOLEAN;
  function ">"   (l : REAL; r : UNRESOLVED_float)    return BOOLEAN;
  function "<"   (l : REAL; r : UNRESOLVED_float)    return BOOLEAN;
  function "="   (l : UNRESOLVED_float; r : INTEGER) return BOOLEAN;
  function "/="  (l : UNRESOLVED_float; r : INTEGER) return BOOLEAN;
  function ">="  (l : UNRESOLVED_float; r : INTEGER) return BOOLEAN;
  function "<="  (l : UNRESOLVED_float; r : INTEGER) return BOOLEAN;
  function ">"   (l : UNRESOLVED_float; r : INTEGER) return BOOLEAN;
  function "<"   (l : UNRESOLVED_float; r : INTEGER) return BOOLEAN;
  function "="   (l : INTEGER; r : UNRESOLVED_float) return BOOLEAN;
  function "/="  (l : INTEGER; r : UNRESOLVED_float) return BOOLEAN;
  function ">="  (l : INTEGER; r : UNRESOLVED_float) return BOOLEAN;
  function "<="  (l : INTEGER; r : UNRESOLVED_float) return BOOLEAN;
  function ">"   (l : INTEGER; r : UNRESOLVED_float) return BOOLEAN;
  function "<"   (l : INTEGER; r : UNRESOLVED_float) return BOOLEAN;
  function \?=\  (l : UNRESOLVED_float; r : REAL)    return STD_ULOGIC;
  function \?/=\ (l : UNRESOLVED_float; r : REAL)    return STD_ULOGIC;
  function \?>\  (l : UNRESOLVED_float; r : REAL)    return STD_ULOGIC;
  function \?>=\ (l : UNRESOLVED_float; r : REAL)    return STD_ULOGIC;
  function \?<\  (l : UNRESOLVED_float; r : REAL)    return STD_ULOGIC;
  function \?<=\ (l : UNRESOLVED_float; r : REAL)    return STD_ULOGIC;
  function \?=\  (l : REAL; r : UNRESOLVED_float)    return STD_ULOGIC;
  function \?/=\ (l : REAL; r : UNRESOLVED_float)    return STD_ULOGIC;
  function \?>\  (l : REAL; r : UNRESOLVED_float)    return STD_ULOGIC;
  function \?>=\ (l : REAL; r : UNRESOLVED_float)    return STD_ULOGIC;
  function \?<\  (l : REAL; r : UNRESOLVED_float)    return STD_ULOGIC;
  function \?<=\ (l : REAL; r : UNRESOLVED_float)    return STD_ULOGIC;
  function \?=\  (l : UNRESOLVED_float; r : INTEGER) return STD_ULOGIC;
  function \?/=\ (l : UNRESOLVED_float; r : INTEGER) return STD_ULOGIC;
  function \?>\  (l : UNRESOLVED_float; r : INTEGER) return STD_ULOGIC;
  function \?>=\ (l : UNRESOLVED_float; r : INTEGER) return STD_ULOGIC;
  function \?<\  (l : UNRESOLVED_float; r : INTEGER) return STD_ULOGIC;
  function \?<=\ (l : UNRESOLVED_float; r : INTEGER) return STD_ULOGIC;
  function \?=\  (l : INTEGER; r : UNRESOLVED_float) return STD_ULOGIC;
  function \?/=\ (l : INTEGER; r : UNRESOLVED_float) return STD_ULOGIC;
  function \?>\  (l : INTEGER; r : UNRESOLVED_float) return STD_ULOGIC;
  function \?>=\ (l : INTEGER; r : UNRESOLVED_float) return STD_ULOGIC;
  function \?<\  (l : INTEGER; r : UNRESOLVED_float) return STD_ULOGIC;
  function \?<=\ (l : INTEGER; r : UNRESOLVED_float) return STD_ULOGIC;
  -- minimum and maximum overloads
  function maximum (l : UNRESOLVED_float; r : REAL)    return UNRESOLVED_float;
  function minimum (l : UNRESOLVED_float; r : REAL)    return UNRESOLVED_float;
  function maximum (l : REAL; r : UNRESOLVED_float)    return UNRESOLVED_float;
  function minimum (l : REAL; r : UNRESOLVED_float)    return UNRESOLVED_float;
  function maximum (l : UNRESOLVED_float; r : INTEGER) return UNRESOLVED_float;
  function minimum (l : UNRESOLVED_float; r : INTEGER) return UNRESOLVED_float;
  function maximum (l : INTEGER; r : UNRESOLVED_float) return UNRESOLVED_float;
  function minimum (l : INTEGER; r : UNRESOLVED_float) return UNRESOLVED_float;
----------------------------------------------------------------------------
  -- logical functions
  ----------------------------------------------------------------------------

  function "not"  (l    : UNRESOLVED_float) return UNRESOLVED_float;
  function "and"  (l, r : UNRESOLVED_float) return UNRESOLVED_float;
  function "or"   (l, r : UNRESOLVED_float) return UNRESOLVED_float;
  function "nand" (l, r : UNRESOLVED_float) return UNRESOLVED_float;
  function "nor"  (l, r : UNRESOLVED_float) return UNRESOLVED_float;
  function "xor"  (l, r : UNRESOLVED_float) return UNRESOLVED_float;
  function "xnor" (l, r : UNRESOLVED_float) return UNRESOLVED_float;
  -- Vector and std_ulogic functions, same as functions in numeric_std
  function "and" (l : STD_ULOGIC; r : UNRESOLVED_float)
    return UNRESOLVED_float;
  function "and" (l : UNRESOLVED_float; r : STD_ULOGIC)
    return UNRESOLVED_float;
  function "or" (l : STD_ULOGIC; r : UNRESOLVED_float)
    return UNRESOLVED_float;
  function "or" (l : UNRESOLVED_float; r : STD_ULOGIC)
    return UNRESOLVED_float;
  function "nand" (l : STD_ULOGIC; r : UNRESOLVED_float)
    return UNRESOLVED_float;
  function "nand" (l : UNRESOLVED_float; r : STD_ULOGIC)
    return UNRESOLVED_float;
  function "nor" (l : STD_ULOGIC; r : UNRESOLVED_float)
    return UNRESOLVED_float;
  function "nor" (l : UNRESOLVED_float; r : STD_ULOGIC)
    return UNRESOLVED_float;
  function "xor" (l : STD_ULOGIC; r : UNRESOLVED_float)
    return UNRESOLVED_float;
  function "xor" (l : UNRESOLVED_float; r : STD_ULOGIC)
    return UNRESOLVED_float;
  function "xnor" (l : STD_ULOGIC; r : UNRESOLVED_float)
    return UNRESOLVED_float;
  function "xnor" (l : UNRESOLVED_float; r : STD_ULOGIC)
    return UNRESOLVED_float;
  -- Reduction operators, same as numeric_std functions
  function and_reduce (l : UNRESOLVED_float) return STD_ULOGIC;
  function nand_reduce (l : UNRESOLVED_float) return STD_ULOGIC;
  function or_reduce (l : UNRESOLVED_float) return STD_ULOGIC;
  function nor_reduce (l : UNRESOLVED_float) return STD_ULOGIC;
  function xor_reduce (l : UNRESOLVED_float) return STD_ULOGIC;
  function xnor_reduce (l : UNRESOLVED_float) return STD_ULOGIC;

  -- Note: "sla", "sra", "sll", "slr", "rol" and "ror" not implemented.

  -----------------------------------------------------------------------------
  -- Recommended Functions from the IEEE 754 Appendix
  -----------------------------------------------------------------------------

  -- returns x with the sign of y.
  function Copysign (x, y : UNRESOLVED_float) return UNRESOLVED_float;

  -- Returns y * 2**n for integral values of N without computing 2**n
  function Scalb (
    y                    : UNRESOLVED_float;  -- floating point input
    N                    : INTEGER;     -- exponent to add    
    constant round_style : round_type := float_round_style;  -- rounding option
    constant check_error : BOOLEAN    := float_check_error;  -- check for errors
    constant denormalize : BOOLEAN    := float_denormalize)  -- Use IEEE extended FP
    return UNRESOLVED_float;

  -- Returns y * 2**n for integral values of N without computing 2**n
  function Scalb (
    y                    : UNRESOLVED_float;  -- floating point input
    N                    : SIGNED;      -- exponent to add    
    constant round_style : round_type := float_round_style;  -- rounding option
    constant check_error : BOOLEAN    := float_check_error;  -- check for errors
    constant denormalize : BOOLEAN    := float_denormalize)  -- Use IEEE extended FP
    return UNRESOLVED_float;

  -- returns the unbiased exponent of x
  function Logb (x : UNRESOLVED_float) return INTEGER;
  function Logb (x : UNRESOLVED_float) return SIGNED;

  -- returns the next representable neighbor of x in the direction toward y
  function Nextafter (
    x, y                 : UNRESOLVED_float;  -- floating point input
    constant check_error : BOOLEAN := float_check_error;  -- check for errors
    constant denormalize : BOOLEAN := float_denormalize)
    return UNRESOLVED_float;

  -- Returns TRUE if X is unordered with Y.
  function Unordered (x, y : UNRESOLVED_float) return BOOLEAN;
  function Finite (x       : UNRESOLVED_float) return BOOLEAN;
  function Isnan (x        : UNRESOLVED_float) return BOOLEAN;

  -- Function to return constants.
  function zerofp (
    constant exponent_width : NATURAL := float_exponent_width;  -- exponent
    constant fraction_width : NATURAL := float_fraction_width)  -- fraction
    return UNRESOLVED_float;
  function nanfp (
    constant exponent_width : NATURAL := float_exponent_width;  -- exponent
    constant fraction_width : NATURAL := float_fraction_width)  -- fraction
    return UNRESOLVED_float;
  function qnanfp (
    constant exponent_width : NATURAL := float_exponent_width;  -- exponent
    constant fraction_width : NATURAL := float_fraction_width)  -- fraction
    return UNRESOLVED_float;
  function pos_inffp (
    constant exponent_width : NATURAL := float_exponent_width;  -- exponent
    constant fraction_width : NATURAL := float_fraction_width)  -- fraction
    return UNRESOLVED_float;
  function neg_inffp (
    constant exponent_width : NATURAL := float_exponent_width;  -- exponent
    constant fraction_width : NATURAL := float_fraction_width)  -- fraction
    return UNRESOLVED_float;
  function neg_zerofp (
    constant exponent_width : NATURAL := float_exponent_width;  -- exponent
    constant fraction_width : NATURAL := float_fraction_width)  -- fraction
    return UNRESOLVED_float;
  -- size_res versions
  function zerofp (
    size_res : UNRESOLVED_float)        -- variable is only use for sizing
    return UNRESOLVED_float;