openieee: complete std_logic_1164 package for vhdl 2008.

7 files changed, 2241 insertions, 20 deletions

diff --git a/libraries/openieee/build_1164.py b/libraries/openieee/build_1164.py
index 87f4ff6d3..042620d2f 100755
--- a/libraries/openieee/build_1164.py
+++ b/libraries/openieee/build_1164.py
@@ -220,9 +220,9 @@ def disp_vec_reduction(func, typ):
 
 def gen_shift(is_left, plus, minus):
     if is_left:
-        s = "res (1 to l'length {1} r) := la (r {0} 1 to res'right);"
+        s = "res (1 to l'length {1} r) := la (r {0} 1 to res'right);\n"
     else:
-        s = "res (1 {0} r to res'right) := la (1 to l'length {1} r);"
+        s = "res (1 {0} r to res'right) := la (1 to l'length {1} r);\n"
     w("      " + s.format(plus, minus))
 
 def disp_shift_funcs(func, typ):
@@ -235,9 +235,9 @@ def disp_shift_funcs(func, typ):
     alias la : res_type is l;
     variable res : res_type := (others => '0');
   begin
-    if r >= 0 then""".format(func, typ))
+    if r >= 0 then\n""".format(func, typ))
     gen_shift(func == "sll", '+', '-')
-    w("    else")
+    w("    else\n")
     gen_shift(func != "sll", '-', '+')
     w("""    end if;
     return res;
@@ -245,12 +245,15 @@ def disp_shift_funcs(func, typ):
 
 def gen_rot(is_left, plus, minus):
     if is_left:
-        s =  "   res (1 to res'right {1} rm) := la (rm {0} 1 to la'right);\n"
-        s += "   res (res'right {1} rm + 1 to res'right) := la (1 to rm);"
+        t = ["res (1 to res'right {1} rm) := la (rm {0} 1 to la'right);",
+             "res (res'right {1} rm + 1 to res'right) := la (1 to rm);"]
     else:
-        s =  "   res (1 {0} rm to res'right) := la (1 to la'right {1} r);]n"
-        s += "   res (1 to rm) := la (la'right {1} rm + 1 to la'right);"
-    w("      " + s.format(plus, minus))
+        t = ["res (1 {0} rm to res'right) := la (1 to la'right {1} r);",
+             "res (1 to rm) := la (la'right {1} rm + 1 to la'right);"]
+    for s in t:
+        w("      ")
+        w(s.format(plus, minus))
+        w('\n')
 
 def disp_rot_funcs(func, typ):
     "Generate rotation functions"
@@ -263,10 +266,10 @@ def disp_rot_funcs(func, typ):
     variable res : res_type;
     constant rm : integer := r mod l'length;
   begin
-    if r >= 0 then""".format(func, typ))
-    gen_shift(func == "rol", '+', '-')
-    w("    else")
-    gen_shift(func != "rol", '-', '+')
+    if r >= 0 then\n""".format(func, typ))
+    gen_rot(func == "rol", '+', '-')
+    w("    else\n")
+    gen_rot(func != "rol", '-', '+')
     w("""    end if;
     return res;
   end "{0}";\n""".format(func, typ))
@@ -510,11 +513,19 @@ def gen_body(filename, version):
     global out
     out = open(filename, 'w')
     w('--  This -*- vhdl -*- file was generated from ' + proto_file + '\n')
+    keep = True
     for line in open(proto_file):
         if line in pats:
             pats[line](version)
             continue
-        w(line)
+        if line == '  @BEG V08\n':
+            keep = (version == V08)
+            continue
+        if line == '  @END V08\n':
+            keep = True
+            continue
+        if keep:
+            w(line)
     out.close()
 
 VDICT={'--V87':  lambda x: x == V87,
diff --git a/libraries/openieee/std_logic_1164-body.proto b/libraries/openieee/std_logic_1164-body.proto
index d214fb16d..21cabbf5f 100644
--- a/libraries/openieee/std_logic_1164-body.proto
+++ b/libraries/openieee/std_logic_1164-body.proto
@@ -120,4 +120,519 @@ package body std_logic_1164 is
                                    '0' | '1' | 'L' | 'H' => false);
 
   @ISX
+  @BEG V08
+
+  function to_ostring (value : std_ulogic_vector) return string
+  is
+    alias avalue : std_ulogic_vector(value'length downto 1) is value;
+    constant len : natural := (value'length + 2) / 3;
+    variable padded : std_ulogic_vector (len * 3 downto 1);
+    variable pad : std_ulogic;
+    variable res : string (len downto 1);
+    variable c : character;
+    subtype res_type is string (1 to len);
+  begin
+    pad := 'Z' when value (value'left) = 'Z' else '0';
+    padded (avalue'range) := to_x01z (value);
+    padded (padded'left downto avalue'left + 1) := (others => pad);
+    for i in res'range loop
+      case padded(i * 3 downto i * 3 - 2) is
+        when "000" =>  c := '0';
+        when "001" =>  c := '1';
+        when "010" =>  c := '2';
+        when "011" =>  c := '3';
+        when "100" =>  c := '4';
+        when "101" =>  c := '5';
+        when "110" =>  c := '6';
+        when "111" =>  c := '7';
+        when "ZZZ" =>  c := 'Z';
+        when others => c := 'X';
+      end case;
+      res (i) := c;
+    end loop;
+    return res_type (res);
+  end to_ostring;
+
+  function to_hstring (value : std_ulogic_vector) return string
+  is
+    alias avalue : std_ulogic_vector(value'length downto 1) is value;
+    constant len : natural := (value'length + 3) / 4;
+    variable padded : std_ulogic_vector (len * 4 downto 1);
+    variable pad : std_ulogic;
+    variable res : string (len downto 1);
+    variable c : character;
+    subtype res_type is string (1 to len);
+  begin
+    pad := 'Z' when value (value'left) = 'Z' else '0';
+    padded (avalue'range) := to_x01z (value);
+    padded (padded'left downto avalue'left + 1) := (others => pad);
+    for i in res'range loop
+      case padded(i * 4 downto i * 4 - 3) is
+        when "0000" =>  c := '0';
+        when "0001" =>  c := '1';
+        when "0010" =>  c := '2';
+        when "0011" =>  c := '3';
+        when "0100" =>  c := '4';
+        when "0101" =>  c := '5';
+        when "0110" =>  c := '6';
+        when "0111" =>  c := '7';
+        when "1000" =>  c := '8';
+        when "1001" =>  c := '9';
+        when "1010" =>  c := 'A';
+        when "1011" =>  c := 'B';
+        when "1100" =>  c := 'C';
+        when "1101" =>  c := 'D';
+        when "1110" =>  c := 'E';
+        when "1111" =>  c := 'F';
+        when "ZZZZ" =>  c := 'Z';
+        when others => c := 'X';
+      end case;
+      res (i) := c;
+    end loop;
+    return res_type (res);
+  end to_hstring;
+
+  type sl_to_char_array is array (std_ulogic) of character;
+  constant sl_to_char : sl_to_char_array := "UX01ZWLH-";
+
+  procedure write (l : inout line; value : std_ulogic;
+                   justified : side := right; field : width := 0) is
+  begin
+    write (l, sl_to_char (value), justified, field);
+  end write;
+
+  procedure write (l : inout line; value : std_ulogic_vector;
+                   justified : side := right; field : width := 0) is
+  begin
+    write (l, to_string (value), justified, field);
+  end write;
+
+  procedure owrite (l : inout line; value : std_ulogic_vector;
+                    justified : side := right; field : width := 0) is
+  begin
+    write (l, to_ostring (value), justified, field);
+  end owrite;
+
+  procedure hwrite (l : inout line; value : std_ulogic_vector;
+                    justified : side := right; field : width := 0) is
+  begin
+    write (l, to_hstring (value), justified, field);
+  end hwrite;
+
+  constant nbsp : character := character'val (160);
+
+  procedure trim (l : inout line; left : natural)
+  is
+    variable nl : line;
+  begin
+    if l'ascending then
+      nl := new string(left to l'right);
+      nl.all := l(left to l'right);
+    else
+      nl := new string(left downto l'right);
+      nl.all := l(left downto l'right);
+    end if;
+    deallocate(l);
+    l := nl;
+  end trim;
+
+  procedure read (l: inout line; value: out std_ulogic; good: out boolean)
+  is
+    variable p : positive;
+    variable dir : integer;
+  begin
+    good := false;
+    value := 'U';
+    if l = null or l'length = 0 then
+      --  Return now for empty line.
+      return;
+    end if;
+
+    if l'ascending then
+      dir := 1;
+    else
+      dir := -1;
+    end if;
+    p := l'left;
+    loop
+      case l(p) is
+        when ' ' | NBSP | HT =>
+          --  Skip blanks.
+          null;
+        when 'U' => value := 'U'; exit;
+        when 'X' => value := 'X'; exit;
+        when '0' => value := '0'; exit;
+        when '1' => value := '1'; exit;
+        when 'Z' => value := 'Z'; exit;
+        when 'W' => value := 'W'; exit;
+        when 'L' => value := 'L'; exit;
+        when 'H' => value := 'H'; exit;
+        when '-' => value := '-'; exit;
+        when others =>
+          trim (l, p);
+          return;
+      end case;
+      if p = l'right then
+        --  End of string.
+        deallocate(l);
+        l := new string'("");
+        return;
+      end if;
+      p := p + dir;
+    end loop;
+
+    good := true;
+    trim (l, p + dir);
+  end read;
+
+  procedure read (l : inout line; value : out std_ulogic)
+  is
+    variable good : boolean;
+  begin
+    read (l, value, good);
+    assert good report "std_logic_1164.read(std_ulogic) cannot read value"
+      severity error;
+  end read;
+
+  procedure read (l : inout line;
+                  value : out std_ulogic_vector; good : out boolean)
+  is
+    variable p : positive;
+    variable i : natural;
+    variable dir : integer;
+    alias av : std_ulogic_vector(1 to value'length) is value;
+    variable allow_underscore : boolean;
+    variable c : character;
+    variable d : std_ulogic;
+  begin
+    good := value'length = 0;
+    value := (value'range => 'U');
+    if l = null or l'length = 0 then
+      --  Return now for empty line.
+      return;
+    end if;
+
+    if l'ascending then
+      dir := 1;
+    else
+      dir := -1;
+    end if;
+    p := l'left;
+
+    --  Skip blanks.
+    p := l'left;
+    loop
+      case l(p) is
+        when ' ' | NBSP | HT =>
+          null;
+        when others =>
+          exit;
+      end case;
+      if p = l'right then
+        --  End of string.
+        deallocate(l);
+        l := new string'("");
+        return;
+      end if;
+      p := p + dir;
+    end loop;
+
+    if value'length = 0 then
+      --  Nothing to read.
+      trim (l, p);
+      return;
+    end if;
+
+    --  Extract value
+    i := 1;
+    allow_underscore := False;
+    good := false;
+    loop
+      c := l(p);
+      case c is
+        when 'U' => d := 'U';
+        when 'X' => d := 'X';
+        when '0' => d := '0';
+        when '1' => d := '1';
+        when 'Z' => d := 'Z';
+        when 'W' => d := 'W';
+        when 'L' => d := 'L';
+        when 'H' => d := 'H';
+        when '-' => d := '-';
+        when others =>
+          if c = '_' and allow_underscore then
+            allow_underscore := false;
+          else
+            --  Invalid character, double or leading '_'.
+            trim (l, p);
+            value := (value'range => 'U');
+            return;
+          end if;
+      end case;
+      if c /= '_' then
+        av (i) := d;
+        allow_underscore := true;
+        if i = av'right then
+          --  Done.
+          good := true;
+          trim (l, p + dir);
+          return;
+        end if;
+        i := i + 1;
+      end if;
+      if p = l'right then
+        --  End of string.
+        trim (l, p + dir);
+        deallocate(l);
+        l := new string'("");
+        value := (value'range => 'U');
+        return;
+      end if;
+      p := p + dir;
+    end loop;
+  end read;
+
+  procedure read (l : inout line; value : out std_ulogic_vector)
+  is
+    variable good : boolean;
+  begin
+    read (l, value, good);
+    assert good
+      report "std_logic_1164.read(std_ulogic_vector) cannot read value"
+      severity error;
+  end read;
+
+  procedure hread (l : inout line;
+                   value : out std_ulogic_vector; good : out boolean)
+  is
+    variable p : positive;
+    variable i : natural;
+    variable dir : integer;
+    constant ndigits : natural := (value'length + 3) / 4;
+    variable v : std_ulogic_vector(1 to ndigits * 4);
+    variable allow_underscore : boolean;
+    variable c : character;
+    variable d : std_ulogic_vector (3 downto 0);
+  begin
+    good := value'length = 0;
+    value := (value'range => 'U');
+    if l = null or l'length = 0 then
+      --  Return now for empty line.
+      return;
+    end if;
+
+    if l'ascending then
+      dir := 1;
+    else
+      dir := -1;
+    end if;
+    p := l'left;
+
+    --  Skip blanks.
+    p := l'left;
+    loop
+      case l(p) is
+        when ' ' | NBSP | HT =>
+          null;
+        when others =>
+          exit;
+      end case;
+      if p = l'right then
+        --  End of string.
+        deallocate(l);
+        l := new string'("");
+        return;
+      end if;
+      p := p + dir;
+    end loop;
+
+    if value'length = 0 then
+      --  Nothing to read.
+      trim (l, p);
+      return;
+    end if;
+
+    --  Extract value
+    i := 0;
+    allow_underscore := False;
+    good := false;
+    loop
+      c := l(p);
+      case c is
+        when '0'       => d := "0000";
+        when '1'       => d := "0001";
+        when '2'       => d := "0010";
+        when '3'       => d := "0011";
+        when '4'       => d := "0100";
+        when '5'       => d := "0101";
+        when '6'       => d := "0110";
+        when '7'       => d := "0111";
+        when '8'       => d := "1000";
+        when '9'       => d := "1001";
+        when 'A' | 'a' => d := "1010";
+        when 'B' | 'b' => d := "1011";
+        when 'C' | 'c' => d := "1100";
+        when 'D' | 'd' => d := "1101";
+        when 'E' | 'e' => d := "1110";
+        when 'F' | 'f' => d := "1111";
+        when 'Z'       => d := "ZZZZ";
+        when 'X'       => d := "XXXX";
+        when others =>
+          if c = '_' and allow_underscore then
+            allow_underscore := false;
+          else
+            --  Invalid character, double or leading '_'.
+            trim (l, p);
+            return;
+          end if;
+      end case;
+      if c /= '_' then
+        allow_underscore := true;
+        v (i * 4 + 1 to i * 4 + 4) := d;
+        i := i + 1;
+        if i = ndigits then
+          --  Done.
+          if or (v(1 to ndigits * 4 - value'length)) /= '1' then
+            --  No truncated digit is a '1'.
+            value := v (ndigits * 4 - value'length + 1 to v'right);
+            good := true;
+          end if;
+          trim (l, p + dir);
+          return;
+        end if;
+      end if;
+      if p = l'right then
+        --  End of string.
+        trim (l, p + dir);
+        deallocate(l);
+        l := new string'("");
+        return;
+      end if;
+      p := p + dir;
+    end loop;
+  end hread;
+
+  procedure hread (l : inout line; value : out std_ulogic_vector)
+  is
+    variable good : boolean;
+  begin
+    hread (l, value, good);
+    assert good
+      report "std_logic_1164.hread(std_ulogic_vector) cannot read value"
+      severity error;
+  end hread;
+
+  procedure oread (l : inout line;
+                   value : out std_ulogic_vector; good : out boolean)
+  is
+    variable p : positive;
+    variable i : natural;
+    variable dir : integer;
+    constant ndigits : natural := (value'length + 2) / 3;
+    variable v : std_ulogic_vector(1 to ndigits * 3);
+    variable allow_underscore : boolean;
+    variable c : character;
+    variable d : std_ulogic_vector (2 downto 0);
+  begin
+    good := value'length = 0;
+    value := (value'range => 'U');
+    if l = null or l'length = 0 then
+      --  Return now for empty line.
+      return;
+    end if;
+
+    if l'ascending then
+      dir := 1;
+    else
+      dir := -1;
+    end if;
+    p := l'left;
+
+    --  Skip blanks.
+    p := l'left;
+    loop
+      case l(p) is
+        when ' ' | NBSP | HT =>
+          null;
+        when others =>
+          exit;
+      end case;
+      if p = l'right then
+        --  End of string.
+        deallocate(l);
+        l := new string'("");
+        return;
+      end if;
+      p := p + dir;
+    end loop;
+
+    if value'length = 0 then
+      --  Nothing to read.
+      trim (l, p);
+      return;
+    end if;
+
+    --  Extract value
+    i := 0;
+    allow_underscore := False;
+    good := false;
+    loop
+      c := l(p);
+      case c is
+        when '0'       => d := "000";
+        when '1'       => d := "001";
+        when '2'       => d := "010";
+        when '3'       => d := "011";
+        when '4'       => d := "100";
+        when '5'       => d := "101";
+        when '6'       => d := "110";
+        when '7'       => d := "111";
+        when 'Z'       => d := "ZZZ";
+        when 'X'       => d := "XXX";
+        when others =>
+          if c = '_' and allow_underscore then
+            allow_underscore := false;
+          else
+            --  Invalid character, double or leading '_'.
+            trim (l, p);
+            return;
+          end if;
+      end case;
+      if c /= '_' then
+        allow_underscore := true;
+        v (i * 3 + 1 to i * 3 + 3) := d;
+        i := i + 1;
+        if i = ndigits then
+          --  Done.
+          if or (v(1 to ndigits * 3 - value'length)) /= '1' then
+            --  No truncated digit is a '1'.
+            value := v (ndigits * 3 - value'length + 1 to v'right);
+            good := true;
+          end if;
+          trim (l, p + dir);
+          return;
+        end if;
+      end if;
+      if p = l'right then
+        --  End of string.
+        trim (l, p + dir);
+        deallocate(l);
+        l := new string'("");
+        return;
+      end if;
+      p := p + dir;
+    end loop;
+  end oread;
+
+  procedure oread (l : inout line; value : out std_ulogic_vector)
+  is
+    variable good : boolean;
+  begin
+    oread (l, value, good);
+    assert good
+      report "std_logic_1164.oread(std_ulogic_vector) cannot read value"
+      severity error;
+  end oread;
+
+  @END V08
 end std_logic_1164;
diff --git a/libraries/openieee/std_logic_1164-body.v08 b/libraries/openieee/std_logic_1164-body.v08
new file mode 100644
index 000000000..25e219c2e
--- /dev/null
+++ b/libraries/openieee/std_logic_1164-body.v08
@@ -0,0 +1,1383 @@
+--  This -*- vhdl -*- file was generated from std_logic_1164-body.proto
+--  This is an implementation of -*- vhdl -*- ieee.std_logic_1164 based only
+--  on the specifications.  This file is part of GHDL.
+--  Copyright (C) 2015 Tristan Gingold
+--
+--  GHDL is free software; you can redistribute it and/or modify it under
+--  the terms of the GNU General Public License as published by the Free
+--  Software Foundation; either version 2, or (at your option) any later
+--  version.
+--
+--  GHDL is distributed in the hope that it will be useful, but WITHOUT ANY
+--  WARRANTY; without even the implied warranty of MERCHANTABILITY or
+--  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+--  for more details.
+--
+--  You should have received a copy of the GNU General Public License
+--  along with GCC; see the file COPYING2.  If not see
+--  <http://www.gnu.org/licenses/>.
+
+--  This is a template file.  To avoid errors and duplication, the python
+--  script build.py generate most of the bodies.
+
+package body std_logic_1164 is
+
+  type table_1d is array (std_ulogic) of std_ulogic;
+  type table_2d is array (std_ulogic, std_ulogic) of std_ulogic;
+
+  constant resolution : table_2d :=
+  --  UX01ZWLH-
+    ("UUUUUUUUU",   --  U
+     "UXXXXXXXX",   --  X
+     "UX0X0000X",   --  0
+     "UXX11111X",   --  1
+     "UX01ZWLHX",   --  Z
+     "UX01WWWWX",   --  W
+     "UX01LWLWX",   --  L
+     "UX01HWWHX",   --  H
+     "UXXXXXXXX"    --  -
+     );
+
+  function resolved (s : std_ulogic_vector) return std_ulogic
+  is
+    variable res : std_ulogic := 'Z';
+  begin
+    for I in s'range loop
+      res := resolution (res, s (I));
+    end loop;
+    return res;
+  end resolved;
+
+
+  constant and_table : table_2d :=
+  --  UX01ZWLH-
+    ("UU0UUU0UU",   -- U
+     "UX0XXX0XX",   -- X
+     "000000000",   -- 0
+     "UX01XX01X",   -- 1
+     "UX0XXX0XX",   -- Z
+     "UX0XXX0XX",   -- W
+     "000000000",   -- L
+     "UX01XX01X",   -- H
+     "UX0XXX0XX"    -- -
+     );
+
+  constant nand_table : table_2d :=
+  --  UX01ZWLH-
+    ("UU1UUU1UU",   -- U
+     "UX1XXX1XX",   -- X
+     "111111111",   -- 0
+     "UX10XX10X",   -- 1
+     "UX1XXX1XX",   -- Z
+     "UX1XXX1XX",   -- W
+     "111111111",   -- L
+     "UX10XX10X",   -- H
+     "UX1XXX1XX"    -- -
+     );
+
+  constant or_table : table_2d :=
+  --  UX01ZWLH-
+    ("UUU1UUU1U",   -- U
+     "UXX1XXX1X",   -- X
+     "UX01XX01X",   -- 0
+     "111111111",   -- 1
+     "UXX1XXX1X",   -- Z
+     "UXX1XXX1X",   -- W
+     "UX01XX01X",   -- L
+     "111111111",   -- H
+     "UXX1XXX1X"    -- -
+     );
+
+  constant nor_table : table_2d :=
+  --  UX01ZWLH-
+    ("UUU0UUU0U",   -- U
+     "UXX0XXX0X",   -- X
+     "UX10XX10X",   -- 0
+     "000000000",   -- 1
+     "UXX0XXX0X",   -- Z
+     "UXX0XXX0X",   -- W
+     "UX10XX10X",   -- L
+     "000000000",   -- H
+     "UXX0XXX0X"    -- -
+     );
+
+  constant xor_table : table_2d :=
+  --  UX01ZWLH-
+    ("UUUUUUUUU",   -- U
+     "UXXXXXXXX",   -- X
+     "UX01XX01X",   -- 0
+     "UX10XX10X",   -- 1
+     "UXXXXXXXX",   -- Z
+     "UXXXXXXXX",   -- W
+     "UX01XX01X",   -- L
+     "UX10XX10X",   -- H
+     "UXXXXXXXX"    -- -
+     );
+
+  constant xnor_table : table_2d :=
+  --  UX01ZWLH-
+    ("UUUUUUUUU",   -- U
+     "UXXXXXXXX",   -- X
+     "UX10XX10X",   -- 0
+     "UX01XX01X",   -- 1
+     "UXXXXXXXX",   -- Z
+     "UXXXXXXXX",   -- W
+     "UX10XX10X",   -- L
+     "UX01XX01X",   -- H
+     "UXXXXXXXX"    -- -
+     );
+
+  constant not_table : table_1d :=
+  --  UX01ZWLH-
+     "UX10XX10X";
+
+
+  function "and" (l : std_ulogic; r : std_ulogic) return UX01 is
+  begin
+    return and_table (l, r);
+  end "and";
+
+  function "nand" (l : std_ulogic; r : std_ulogic) return UX01 is
+  begin
+    return nand_table (l, r);
+  end "nand";
+
+  function "or" (l : std_ulogic; r : std_ulogic) return UX01 is
+  begin
+    return or_table (l, r);
+  end "or";
+
+  function "nor" (l : std_ulogic; r : std_ulogic) return UX01 is
+  begin
+    return nor_table (l, r);
+  end "nor";
+
+  function "xor" (l : std_ulogic; r : std_ulogic) return UX01 is
+  begin
+    return xor_table (l, r);
+  end "xor";
+
+  function "xnor" (l : std_ulogic; r : std_ulogic) return UX01 is
+  begin
+    return xnor_table (l, r);
+  end "xnor";
+
+  function "not" (l : std_ulogic) return UX01 is
+  begin
+    return not_table (l);
+  end "not";
+
+  function "and" (l, r : std_ulogic_vector) return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    alias ra : std_ulogic_vector (1 to r'length) is r;
+    variable res : res_type;
+  begin
+    if la'length /= ra'length then
+      assert false
+        report "arguments of overloaded 'and' operator are not of the same length"
+        severity failure;
+    else
+      for I in res_type'range loop
+        res (I) := and_table (la (I), ra (I));
+      end loop;
+    end if;
+    return res;
+  end "and";
+
+  function "nand" (l, r : std_ulogic_vector) return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    alias ra : std_ulogic_vector (1 to r'length) is r;
+    variable res : res_type;
+  begin
+    if la'length /= ra'length then
+      assert false
+        report "arguments of overloaded 'nand' operator are not of the same length"
+        severity failure;
+    else
+      for I in res_type'range loop
+        res (I) := nand_table (la (I), ra (I));
+      end loop;
+    end if;
+    return res;
+  end "nand";
+
+  function "or" (l, r : std_ulogic_vector) return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    alias ra : std_ulogic_vector (1 to r'length) is r;
+    variable res : res_type;
+  begin
+    if la'length /= ra'length then
+      assert false
+        report "arguments of overloaded 'or' operator are not of the same length"
+        severity failure;
+    else
+      for I in res_type'range loop
+        res (I) := or_table (la (I), ra (I));
+      end loop;
+    end if;
+    return res;
+  end "or";
+
+  function "nor" (l, r : std_ulogic_vector) return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    alias ra : std_ulogic_vector (1 to r'length) is r;
+    variable res : res_type;
+  begin
+    if la'length /= ra'length then
+      assert false
+        report "arguments of overloaded 'nor' operator are not of the same length"
+        severity failure;
+    else
+      for I in res_type'range loop
+        res (I) := nor_table (la (I), ra (I));
+      end loop;
+    end if;
+    return res;
+  end "nor";
+
+  function "xor" (l, r : std_ulogic_vector) return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    alias ra : std_ulogic_vector (1 to r'length) is r;
+    variable res : res_type;
+  begin
+    if la'length /= ra'length then
+      assert false
+        report "arguments of overloaded 'xor' operator are not of the same length"
+        severity failure;
+    else
+      for I in res_type'range loop
+        res (I) := xor_table (la (I), ra (I));
+      end loop;
+    end if;
+    return res;
+  end "xor";
+
+  function "xnor" (l, r : std_ulogic_vector) return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    alias ra : std_ulogic_vector (1 to r'length) is r;
+    variable res : res_type;
+  begin
+    if la'length /= ra'length then
+      assert false
+        report "arguments of overloaded 'xnor' operator are not of the same length"
+        severity failure;
+    else
+      for I in res_type'range loop
+        res (I) := xnor_table (la (I), ra (I));
+      end loop;
+    end if;
+    return res;
+  end "xnor";
+
+  function "not" (l : std_ulogic_vector) return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    variable res : res_type;
+  begin
+    for I in res_type'range loop
+      res (I) := not_table (la (I));
+    end loop;
+    return res;
+  end "not";
+
+  function "and" (l : std_ulogic_vector; r : std_ulogic)
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    variable res : res_type;
+  begin
+    for I in res_type'range loop
+      res (I) := and_table (la (I), r);
+    end loop;
+    return res;
+  end "and";
+
+  function "and" (l : std_ulogic; r : std_ulogic_vector)
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to r'length);
+    alias ra : res_type is r;
+    variable res : res_type;
+  begin
+    for I in res_type'range loop
+      res (I) := and_table (l, ra (I));
+    end loop;
+    return res;
+  end "and";
+
+  function "nand" (l : std_ulogic_vector; r : std_ulogic)
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    variable res : res_type;
+  begin
+    for I in res_type'range loop
+      res (I) := nand_table (la (I), r);
+    end loop;
+    return res;
+  end "nand";
+
+  function "nand" (l : std_ulogic; r : std_ulogic_vector)
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to r'length);
+    alias ra : res_type is r;
+    variable res : res_type;
+  begin
+    for I in res_type'range loop
+      res (I) := nand_table (l, ra (I));
+    end loop;
+    return res;
+  end "nand";
+
+  function "or" (l : std_ulogic_vector; r : std_ulogic)
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    variable res : res_type;
+  begin
+    for I in res_type'range loop
+      res (I) := or_table (la (I), r);
+    end loop;
+    return res;
+  end "or";
+
+  function "or" (l : std_ulogic; r : std_ulogic_vector)
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to r'length);
+    alias ra : res_type is r;
+    variable res : res_type;
+  begin
+    for I in res_type'range loop
+      res (I) := or_table (l, ra (I));
+    end loop;
+    return res;
+  end "or";
+
+  function "nor" (l : std_ulogic_vector; r : std_ulogic)
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    variable res : res_type;
+  begin
+    for I in res_type'range loop
+      res (I) := nor_table (la (I), r);
+    end loop;
+    return res;
+  end "nor";
+
+  function "nor" (l : std_ulogic; r : std_ulogic_vector)
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to r'length);
+    alias ra : res_type is r;
+    variable res : res_type;
+  begin
+    for I in res_type'range loop
+      res (I) := nor_table (l, ra (I));
+    end loop;
+    return res;
+  end "nor";
+
+  function "xor" (l : std_ulogic_vector; r : std_ulogic)
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    variable res : res_type;
+  begin
+    for I in res_type'range loop
+      res (I) := xor_table (la (I), r);
+    end loop;
+    return res;
+  end "xor";
+
+  function "xor" (l : std_ulogic; r : std_ulogic_vector)
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to r'length);
+    alias ra : res_type is r;
+    variable res : res_type;
+  begin
+    for I in res_type'range loop
+      res (I) := xor_table (l, ra (I));
+    end loop;
+    return res;
+  end "xor";
+
+  function "xnor" (l : std_ulogic_vector; r : std_ulogic)
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    variable res : res_type;
+  begin
+    for I in res_type'range loop
+      res (I) := xnor_table (la (I), r);
+    end loop;
+    return res;
+  end "xnor";
+
+  function "xnor" (l : std_ulogic; r : std_ulogic_vector)
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to r'length);
+    alias ra : res_type is r;
+    variable res : res_type;
+  begin
+    for I in res_type'range loop
+      res (I) := xnor_table (l, ra (I));
+    end loop;
+    return res;
+  end "xnor";
+
+  function "and" (l : std_ulogic_vector) return std_ulogic
+  is
+    variable res : std_ulogic := '1';
+  begin
+    for I in l'range loop
+      res := and_table (l(I), res);
+    end loop;
+    return res;
+  end "and";
+
+  function "nand" (l : std_ulogic_vector) return std_ulogic
+  is
+    variable res : std_ulogic := '1';
+  begin
+    for I in l'range loop
+      res := nand_table (l(I), res);
+    end loop;
+    return res;
+  end "nand";
+
+  function "or" (l : std_ulogic_vector) return std_ulogic
+  is
+    variable res : std_ulogic := '0';
+  begin
+    for I in l'range loop
+      res := or_table (l(I), res);
+    end loop;
+    return res;
+  end "or";
+
+  function "nor" (l : std_ulogic_vector) return std_ulogic
+  is
+    variable res : std_ulogic := '0';
+  begin
+    for I in l'range loop
+      res := nor_table (l(I), res);
+    end loop;
+    return res;
+  end "nor";
+
+  function "xor" (l : std_ulogic_vector) return std_ulogic
+  is
+    variable res : std_ulogic := '0';
+  begin
+    for I in l'range loop
+      res := xor_table (l(I), res);
+    end loop;
+    return res;
+  end "xor";
+
+  function "xnor" (l : std_ulogic_vector) return std_ulogic
+  is
+    variable res : std_ulogic := '0';
+  begin
+    for I in l'range loop
+      res := xnor_table (l(I), res);
+    end loop;
+    return res;
+  end "xnor";
+
+  function "sll" (l : std_ulogic_vector; r : integer)
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    variable res : res_type := (others => '0');
+  begin
+    if r >= 0 then
+      res (1 to l'length - r) := la (r + 1 to res'right);
+    else
+      res (1 - r to res'right) := la (1 to l'length + r);
+    end if;
+    return res;
+  end "sll";
+
+  function "srl" (l : std_ulogic_vector; r : integer)
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    variable res : res_type := (others => '0');
+  begin
+    if r >= 0 then
+      res (1 + r to res'right) := la (1 to l'length - r);
+    else
+      res (1 to l'length + r) := la (r - 1 to res'right);
+    end if;
+    return res;
+  end "srl";
+
+  function "rol" (l : std_ulogic_vector; r : integer)
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    variable res : res_type;
+    constant rm : integer := r mod l'length;
+  begin
+    if r >= 0 then
+      res (1 to res'right - rm) := la (rm + 1 to la'right);
+      res (res'right - rm + 1 to res'right) := la (1 to rm);
+    else
+      res (1 - rm to res'right) := la (1 to la'right + r);
+      res (1 to rm) := la (la'right + rm + 1 to la'right);
+    end if;
+    return res;
+  end "rol";
+
+  function "ror" (l : std_ulogic_vector; r : integer)
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to l'length);
+    alias la : res_type is l;
+    variable res : res_type;
+    constant rm : integer := r mod l'length;
+  begin
+    if r >= 0 then
+      res (1 + rm to res'right) := la (1 to la'right - r);
+      res (1 to rm) := la (la'right - rm + 1 to la'right);
+    else
+      res (1 to res'right + rm) := la (rm - 1 to la'right);
+      res (res'right + rm + 1 to res'right) := la (1 to rm);
+    end if;
+    return res;
+  end "ror";
+
+  --  Conversion functions.
+  --  The result range (for vectors) is S'Length - 1 downto 0.
+  --  XMAP is return for values not in '0', '1', 'L', 'H'.
+  function to_bit (s : std_ulogic; xmap : bit := '0') return bit is
+  begin
+    case s is
+      when '0' | 'L' =>
+        return '0';
+      when '1' | 'H' =>
+        return '1';
+      when others =>
+        return xmap;
+    end case;
+  end to_bit;
+
+  type bit_to_std_table is array (bit) of std_ulogic;
+  constant bit_to_std : bit_to_std_table := "01";
+
+
+  function to_bitvector (s : std_ulogic_vector; xmap : bit := '0')
+    return bit_vector
+  is
+    subtype res_range is natural range s'length - 1 downto 0;
+    alias as : std_ulogic_vector (res_range) is s;
+    variable res : bit_vector (res_range);
+    variable b : bit;
+  begin
+    for I in res_range loop
+      --  Inline for efficiency.
+      case as (I) is
+        when '0' | 'L' =>
+          b := '0';
+        when '1' | 'H' =>
+          b := '1';
+        when others =>
+          b := xmap;
+      end case;
+      res (I) := b;
+    end loop;
+    return res;
+  end to_bitvector;
+
+  function to_stdulogicvector (b : bit_vector) return std_ulogic_vector is
+    subtype res_range is natural range b'length - 1 downto 0;
+    alias ab : bit_vector (res_range) is b;
+    variable res : std_ulogic_vector (res_range);
+  begin
+    for I in res_range loop
+      res (I) := bit_to_std (ab (I));
+    end loop;
+    return res;
+  end to_stdulogicvector;
+
+  function to_stdlogicvector (b : bit_vector) return std_logic_vector is
+    subtype res_range is natural range b'length - 1 downto 0;
+    alias ab : bit_vector (res_range) is b;
+    variable res : std_logic_vector (res_range);
+  begin
+    for I in res_range loop
+      res (I) := bit_to_std (ab (I));
+    end loop;
+    return res;
+  end to_stdlogicvector;
+
+  function to_stdulogicvector (s : std_logic_vector) return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (s'length - 1 downto 0);
+  begin
+    return res_type (s);
+  end to_stdulogicvector;
+
+  function to_stdlogicvector (s : std_ulogic_vector) return std_logic_vector
+  is
+    subtype res_type is std_logic_vector (s'length - 1 downto 0);
+  begin
+    return res_type (s);
+  end to_stdlogicvector;
+
+  function to_stdulogic (b : bit) return std_ulogic is
+  begin
+    return bit_to_std (b);
+  end to_stdulogic;
+
+  --  Normalization.
+  type table_std_x01 is array (std_ulogic) of X01;
+  constant std_to_x01 : table_std_x01 := ('U' | 'X' | 'Z' | 'W' | '-' => 'X',
+                                          '0' | 'L'                   => '0',
+                                          '1' | 'H'                   => '1');
+
+  type table_bit_x01 is array (bit) of X01;
+  constant bit_to_x01 : table_bit_x01 := ('0' => '0',
+                                          '1' => '1');
+
+
+  type table_std_x01z is array (std_ulogic) of X01Z;
+  constant std_to_x01z : table_std_x01z := ('U' | 'X' | 'W' | '-' => 'X',
+                                            '0' | 'L'             => '0',
+                                            '1' | 'H'             => '1',
+                                            'Z'                   => 'Z');
+
+  type table_std_ux01 is array (std_ulogic) of UX01;
+  constant std_to_ux01 : table_std_ux01 := ('U'                   => 'U',
+                                            'X' | 'Z' | 'W' | '-' => 'X',
+                                            '0' | 'L'             => '0',
+                                            '1' | 'H'             => '1');
+
+
+  function to_01 (s : std_ulogic_vector; xmap : std_ulogic := '0')
+    return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (s'length - 1 downto 0);
+    alias sa : res_type is s;
+    variable res : res_type;
+  begin
+    for i in res_type'range loop
+      case sa(i) is
+        when '0' | 'L' => res (i) := '0';
+        when '1' | 'H' => res (i) := '1';
+        when others    => return res_type'(others => xmap);
+      end case;
+    end loop;
+    return res;
+  end to_01;
+
+  function to_01 (s : std_ulogic; xmap : std_ulogic := '0')
+    return std_ulogic is
+  begin
+    case s is
+      when '0' | 'L' => return '0';
+      when '1' | 'H' => return '1';
+      when others    => return xmap;
+    end case;
+  end to_01;
+
+  function to_01 (s : bit_vector; xmap : std_ulogic := '0')
+    return std_ulogic_vector
+  is
+    alias sa : bit_vector(s'length - 1 downto 0) is s;
+    variable res : std_ulogic_vector (s'length - 1 downto 0);
+  begin
+    for i in sa'range loop
+      res (i) := bit_to_std (sa (i));
+    end loop;
+    return res;
+  end to_01;
+
+  function to_01 (s : bit; xmap : std_ulogic := '0')
+    return std_ulogic is
+  begin
+    return bit_to_std(s);
+  end to_01;
+
+  function to_X01 (s : std_ulogic_vector) return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to s'length);
+    alias sa : res_type is s;
+    variable res : res_type;
+  begin
+    for i in res_type'range loop
+      res (i) := std_to_x01 (sa (i));
+    end loop;
+    return res;
+  end to_X01;
+
+  function to_X01 (s : std_ulogic) return X01 is
+  begin
+    return std_to_x01 (s);
+  end to_X01;
+
+  function to_X01 (b : bit_vector) return std_ulogic_vector
+  is
+    subtype res_range is natural range 1 to b'length;
+    alias ba : bit_vector (res_range) is b;
+    variable res : std_ulogic_vector (res_range);
+  begin
+    for i in res_range loop
+      res (i) := bit_to_x01 (ba (i));
+    end loop;
+    return res;
+  end to_X01;
+
+  function to_X01 (b : bit) return X01 is
+  begin
+    return bit_to_x01 (b);
+  end to_X01;
+
+  function to_X01Z (s : std_ulogic_vector) return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to s'length);
+    alias sa : res_type is s;
+    variable res : res_type;
+  begin
+    for i in res_type'range loop
+      res (i) := std_to_x01z (sa (i));
+    end loop;
+    return res;
+  end to_X01Z;
+
+  function to_X01Z (s : std_ulogic) return X01Z is
+  begin
+    return std_to_x01z (s);
+  end to_X01Z;
+
+  function to_X01Z (b : bit_vector) return std_ulogic_vector
+  is
+    subtype res_range is natural range 1 to b'length;
+    alias ba : bit_vector (res_range) is b;
+    variable res : std_ulogic_vector (res_range);
+  begin
+    for i in res_range loop
+      res (i) := bit_to_x01 (ba (i));
+    end loop;
+    return res;
+  end to_X01Z;
+
+  function to_X01Z (b : bit) return X01Z is
+  begin
+    return bit_to_x01 (b);
+  end to_X01Z;
+
+  function to_UX01 (s : std_ulogic_vector) return std_ulogic_vector
+  is
+    subtype res_type is std_ulogic_vector (1 to s'length);
+    alias sa : res_type is s;
+    variable res : res_type;
+  begin
+    for i in res_type'range loop
+      res (i) := std_to_ux01 (sa (i));
+    end loop;
+    return res;
+  end to_UX01;
+
+  function to_UX01 (s : std_ulogic) return UX01 is
+  begin
+    return std_to_ux01 (s);
+  end to_UX01;
+
+  function to_UX01 (b : bit_vector) return std_ulogic_vector
+  is
+    subtype res_range is natural range 1 to b'length;
+    alias ba : bit_vector (res_range) is b;
+    variable res : std_ulogic_vector (res_range);
+  begin
+    for i in res_range loop
+      res (i) := bit_to_x01 (ba (i));
+    end loop;
+    return res;
+  end to_UX01;
+
+  function to_UX01 (b : bit) return UX01 is
+  begin
+    return bit_to_x01 (b);
+  end to_UX01;
+
+  function "??" (l : std_ulogic) return boolean is
+  begin
+    return l = '1' or l = 'H';
+  end "??";
+
+  function rising_edge (signal s : std_ulogic) return boolean is
+  begin
+    return s'event
+      and to_x01 (s'last_value) = '0'
+      and to_x01 (s) = '1';
+  end rising_edge;
+
+  function falling_edge (signal s : std_ulogic) return boolean is
+  begin
+    return s'event
+      and to_x01 (s'last_value) = '1'
+      and to_x01 (s) = '0';
+  end falling_edge;
+
+  type std_x_array is array (std_ulogic) of boolean;
+  constant std_x : std_x_array := ('U' | 'X' | 'Z' | 'W' | '-' => true,
+                                   '0' | '1' | 'L' | 'H' => false);
+
+
+  function is_X (s : std_ulogic_vector) return boolean is
+  begin
+    for i in s'range loop
+      if std_x (s (i)) then
+        return true;
+      end if;
+    end loop;
+    return false;
+  end is_X;
+
+  function is_X (s : std_ulogic) return boolean is
+  begin
+    return std_x (s);
+  end is_X;
+
+  function to_ostring (value : std_ulogic_vector) return string
+  is
+    alias avalue : std_ulogic_vector(value'length downto 1) is value;
+    constant len : natural := (value'length + 2) / 3;
+    variable padded : std_ulogic_vector (len * 3 downto 1);
+    variable pad : std_ulogic;
+    variable res : string (len downto 1);
+    variable c : character;
+    subtype res_type is string (1 to len);
+  begin
+    pad := 'Z' when value (value'left) = 'Z' else '0';
+    padded (avalue'range) := to_x01z (value);
+    padded (padded'left downto avalue'left + 1) := (others => pad);
+    for i in res'range loop
+      case padded(i * 3 downto i * 3 - 2) is
+        when "000" =>  c := '0';
+        when "001" =>  c := '1';
+        when "010" =>  c := '2';
+        when "011" =>  c := '3';
+        when "100" =>  c := '4';
+        when "101" =>  c := '5';
+        when "110" =>  c := '6';
+        when "111" =>  c := '7';
+        when "ZZZ" =>  c := 'Z';
+        when others => c := 'X';
+      end case;
+      res (i) := c;
+    end loop;
+    return res_type (res);
+  end to_ostring;
+
+  function to_hstring (value : std_ulogic_vector) return string
+  is
+    alias avalue : std_ulogic_vector(value'length downto 1) is value;
+    constant len : natural := (value'length + 3) / 4;
+    variable padded : std_ulogic_vector (len * 4 downto 1);
+    variable pad : std_ulogic;
+    variable res : string (len downto 1);
+    variable c : character;
+    subtype res_type is string (1 to len);
+  begin
+    pad := 'Z' when value (value'left) = 'Z' else '0';
+    padded (avalue'range) := to_x01z (value);
+    padded (padded'left downto avalue'left + 1) := (others => pad);
+    for i in res'range loop
+      case padded(i * 4 downto i * 4 - 3) is
+        when "0000" =>  c := '0';
+        when "0001" =>  c := '1';
+        when "0010" =>  c := '2';
+        when "0011" =>  c := '3';
+        when "0100" =>  c := '4';
+        when "0101" =>  c := '5';
+        when "0110" =>  c := '6';
+        when "0111" =>  c := '7';
+        when "1000" =>  c := '8';
+        when "1001" =>  c := '9';
+        when "1010" =>  c := 'A';
+        when "1011" =>  c := 'B';
+        when "1100" =>  c := 'C';
+        when "1101" =>  c := 'D';
+        when "1110" =>  c := 'E';
+        when "1111" =>  c := 'F';
+        when "ZZZZ" =>  c := 'Z';
+        when others => c := 'X';
+      end case;
+      res (i) := c;
+    end loop;
+    return res_type (res);
+  end to_hstring;
+
+  type sl_to_char_array is array (std_ulogic) of character;
+  constant sl_to_char : sl_to_char_array := "UX01ZWLH-";
+
+  procedure write (l : inout line; value : std_ulogic;
+                   justified : side := right; field : width := 0) is
+  begin
+    write (l, sl_to_char (value), justified, field);
+  end write;
+
+  procedure write (l : inout line; value : std_ulogic_vector;
+                   justified : side := right; field : width := 0) is
+  begin
+    write (l, to_string (value), justified, field);
+  end write;
+
+  procedure owrite (l : inout line; value : std_ulogic_vector;
+                    justified : side := right; field : width := 0) is
+  begin
+    write (l, to_ostring (value), justified, field);
+  end owrite;
+
+  procedure hwrite (l : inout line; value : std_ulogic_vector;
+                    justified : side := right; field : width := 0) is
+  begin
+    write (l, to_hstring (value), justified, field);
+  end hwrite;
+
+  constant nbsp : character := character'val (160);
+
+  procedure trim (l : inout line; left : natural)
+  is
+    variable nl : line;
+  begin
+    if l'ascending then
+      nl := new string(left to l'right);
+      nl.all := l(left to l'right);
+    else
+      nl := new string(left downto l'right);
+      nl.all := l(left downto l'right);
+    end if;
+    deallocate(l);
+    l := nl;
+  end trim;
+
+  procedure read (l: inout line; value: out std_ulogic; good: out boolean)
+  is
+    variable p : positive;
+    variable dir : integer;
+  begin
+    good := false;
+    value := 'U';
+    if l = null or l'length = 0 then
+      --  Return now for empty line.
+      return;
+    end if;
+
+    if l'ascending then
+      dir := 1;
+    else
+      dir := -1;
+    end if;
+    p := l'left;
+    loop
+      case l(p) is
+        when ' ' | NBSP | HT =>
+          --  Skip blanks.
+          null;
+        when 'U' => value := 'U'; exit;
+        when 'X' => value := 'X'; exit;
+        when '0' => value := '0'; exit;
+        when '1' => value := '1'; exit;
+        when 'Z' => value := 'Z'; exit;
+        when 'W' => value := 'W'; exit;
+        when 'L' => value := 'L'; exit;
+        when 'H' => value := 'H'; exit;
+        when '-' => value := '-'; exit;
+        when others =>
+          trim (l, p);
+          return;
+      end case;
+      if p = l'right then
+        --  End of string.
+        deallocate(l);
+        l := new string'("");
+        return;
+      end if;
+      p := p + dir;
+    end loop;
+
+    good := true;
+    trim (l, p + dir);
+  end read;
+
+  procedure read (l : inout line; value : out std_ulogic)
+  is
+    variable good : boolean;
+  begin
+    read (l, value, good);
+    assert good report "std_logic_1164.read(std_ulogic) cannot read value"
+      severity error;
+  end read;
+
+  procedure read (l : inout line;
+                  value : out std_ulogic_vector; good : out boolean)
+  is
+    variable p : positive;
+    variable i : natural;
+    variable dir : integer;
+    alias av : std_ulogic_vector(1 to value'length) is value;
+    variable allow_underscore : boolean;
+    variable c : character;
+    variable d : std_ulogic;
+  begin
+    good := value'length = 0;
+    value := (value'range => 'U');
+    if l = null or l'length = 0 then
+      --  Return now for empty line.
+      return;
+    end if;
+
+    if l'ascending then
+      dir := 1;
+    else
+      dir := -1;
+    end if;
+    p := l'left;
+
+    --  Skip blanks.
+    p := l'left;
+    loop
+      case l(p) is
+        when ' ' | NBSP | HT =>
+          null;
+        when others =>
+          exit;
+      end case;
+      if p = l'right then
+        --  End of string.
+        deallocate(l);
+        l := new string'("");
+        return;
+      end if;
+      p := p + dir;
+    end loop;
+
+    if value'length = 0 then
+      --  Nothing to read.
+      trim (l, p);
+      return;
+    end if;
+
+    --  Extract value
+    i := 1;
+    allow_underscore := False;
+    good := false;
+    loop
+      c := l(p);
+      case c is
+        when 'U' => d := 'U';
+        when 'X' => d := 'X';
+        when '0' => d := '0';
+        when '1' => d := '1';
+        when 'Z' => d := 'Z';
+        when 'W' => d := 'W';
+        when 'L' => d := 'L';
+        when 'H' => d := 'H';
+        when '-' => d := '-';
+        when others =>
+          if c = '_' and allow_underscore then
+            allow_underscore := false;
+          else
+            --  Invalid character, double or leading '_'.
+            trim (l, p);
+            value := (value'range => 'U');
+            return;
+          end if;
+      end case;
+      if c /= '_' then
+        av (i) := d;
+        allow_underscore := true;
+        if i = av'right then
+          --  Done.
+          good := true;
+          trim (l, p + dir);
+          return;
+        end if;
+        i := i + 1;
+      end if;
+      if p = l'right then
+        --  End of string.
+        trim (l, p + dir);
+        deallocate(l);
+        l := new string'("");
+        value := (value'range => 'U');
+        return;
+      end if;
+      p := p + dir;
+    end loop;
+  end read;
+
+  procedure read (l : inout line; value : out std_ulogic_vector)
+  is
+    variable good : boolean;
+  begin
+    read (l, value, good);
+    assert good
+      report "std_logic_1164.read(std_ulogic_vector) cannot read value"
+      severity error;
+  end read;
+
+  procedure hread (l : inout line;
+                   value : out std_ulogic_vector; good : out boolean)
+  is
+    variable p : positive;
+    variable i : natural;
+    variable dir : integer;
+    constant ndigits : natural := (value'length + 3) / 4;
+    variable v : std_ulogic_vector(1 to ndigits * 4);
+    variable allow_underscore : boolean;
+    variable c : character;
+    variable d : std_ulogic_vector (3 downto 0);
+  begin
+    good := value'length = 0;
+    value := (value'range => 'U');
+    if l = null or l'length = 0 then
+      --  Return now for empty line.
+      return;
+    end if;
+
+    if l'ascending then
+      dir := 1;
+    else
+      dir := -1;
+    end if;
+    p := l'left;
+
+    --  Skip blanks.
+    p := l'left;
+    loop
+      case l(p) is
+        when ' ' | NBSP | HT =>
+          null;
+        when others =>
+          exit;
+      end case;
+      if p = l'right then
+        --  End of string.
+        deallocate(l);
+        l := new string'("");
+        return;
+      end if;
+      p := p + dir;
+    end loop;
+
+    if value'length = 0 then
+      --  Nothing to read.
+      trim (l, p);
+      return;
+    end if;
+
+    --  Extract value
+    i := 0;
+    allow_underscore := False;
+    good := false;
+    loop
+      c := l(p);
+      case c is
+        when '0'       => d := "0000";
+        when '1'       => d := "0001";
+        when '2'       => d := "0010";
+        when '3'       => d := "0011";
+        when '4'       => d := "0100";
+        when '5'       => d := "0101";
+        when '6'       => d := "0110";
+        when '7'       => d := "0111";
+        when '8'       => d := "1000";
+        when '9'       => d := "1001";
+        when 'A' | 'a' => d := "1010";
+        when 'B' | 'b' => d := "1011";
+        when 'C' | 'c' => d := "1100";
+        when 'D' | 'd' => d := "1101";
+        when 'E' | 'e' => d := "1110";
+        when 'F' | 'f' => d := "1111";
+        when 'Z'       => d := "ZZZZ";
+        when 'X'       => d := "XXXX";
+        when others =>
+          if c = '_' and allow_underscore then
+            allow_underscore := false;
+          else
+            --  Invalid character, double or leading '_'.
+            trim (l, p);
+            return;
+          end if;
+      end case;
+      if c /= '_' then
+        allow_underscore := true;
+        v (i * 4 + 1 to i * 4 + 4) := d;
+        i := i + 1;
+        if i = ndigits then
+          --  Done.
+          if or (v(1 to ndigits * 4 - value'length)) /= '1' then
+            --  No truncated digit is a '1'.
+            value := v (ndigits * 4 - value'length + 1 to v'right);
+            good := true;
+          end if;
+          trim (l, p + dir);
+          return;
+        end if;
+      end if;
+      if p = l'right then
+        --  End of string.
+        trim (l, p + dir);
+        deallocate(l);
+        l := new string'("");
+        return;
+      end if;
+      p := p + dir;
+    end loop;
+  end hread;
+
+  procedure hread (l : inout line; value : out std_ulogic_vector)
+  is
+    variable good : boolean;
+  begin
+    hread (l, value, good);
+    assert good
+      report "std_logic_1164.hread(std_ulogic_vector) cannot read value"
+      severity error;
+  end hread;
+
+  procedure oread (l : inout line;
+                   value : out std_ulogic_vector; good : out boolean)
+  is
+    variable p : positive;
+    variable i : natural;
+    variable dir : integer;
+    constant ndigits : natural := (value'length + 2) / 3;
+    variable v : std_ulogic_vector(1 to ndigits * 3);
+    variable allow_underscore : boolean;
+    variable c : character;
+    variable d : std_ulogic_vector (2 downto 0);
+  begin
+    good := value'length = 0;
+    value := (value'range => 'U');
+    if l = null or l'length = 0 then
+      --  Return now for empty line.
+      return;
+    end if;
+
+    if l'ascending then
+      dir := 1;
+    else
+      dir := -1;
+    end if;
+    p := l'left;
+
+    --  Skip blanks.
+    p := l'left;
+    loop
+      case l(p) is
+        when ' ' | NBSP | HT =>
+          null;
+        when others =>
+          exit;
+      end case;
+      if p = l'right then
+        --  End of string.
+        deallocate(l);
+        l := new string'("");
+        return;
+      end if;
+      p := p + dir;
+    end loop;
+
+    if value'length = 0 then
+      --  Nothing to read.
+      trim (l, p);
+      return;
+    end if;
+
+    --  Extract value
+    i := 0;
+    allow_underscore := False;
+    good := false;
+    loop
+      c := l(p);
+      case c is
+        when '0'       => d := "000";
+        when '1'       => d := "001";
+        when '2'       => d := "010";
+        when '3'       => d := "011";
+        when '4'       => d := "100";
+        when '5'       => d := "101";
+        when '6'       => d := "110";
+        when '7'       => d := "111";
+        when 'Z'       => d := "ZZZ";
+        when 'X'       => d := "XXX";
+        when others =>
+          if c = '_' and allow_underscore then
+            allow_underscore := false;
+          else
+            --  Invalid character, double or leading '_'.
+            trim (l, p);
+            return;
+          end if;
+      end case;
+      if c /= '_' then
+        allow_underscore := true;
+        v (i * 3 + 1 to i * 3 + 3) := d;
+        i := i + 1;
+        if i = ndigits then
+          --  Done.
+          if or (v(1 to ndigits * 3 - value'length)) /= '1' then
+            --  No truncated digit is a '1'.
+            value := v (ndigits * 3 - value'length + 1 to v'right);
+            good := true;
+          end if;
+          trim (l, p + dir);
+          return;
+        end if;
+      end if;
+      if p = l'right then
+        --  End of string.
+        trim (l, p + dir);
+        deallocate(l);
+        l := new string'("");
+        return;
+      end if;
+      p := p + dir;
+    end loop;
+  end oread;
+
+  procedure oread (l : inout line; value : out std_ulogic_vector)
+  is
+    variable good : boolean;
+  begin
+    oread (l, value, good);
+    assert good
+      report "std_logic_1164.oread(std_ulogic_vector) cannot read value"
+      severity error;
+  end oread;
+
+end std_logic_1164;
diff --git a/libraries/openieee/std_logic_1164.v08 b/libraries/openieee/std_logic_1164.v08
new file mode 100644
index 000000000..8271b1b93
--- /dev/null
+++ b/libraries/openieee/std_logic_1164.v08
@@ -0,0 +1,257 @@
+--  This is an implementation of -*- vhdl -*- ieee.std_logic_1164 based only
+--  on the specifications.  This file is part of GHDL.
+--  Copyright (C) 2015 Tristan Gingold
+--
+--  GHDL is free software; you can redistribute it and/or modify it under
+--  the terms of the GNU General Public License as published by the Free
+--  Software Foundation; either version 2, or (at your option) any later
+--  version.
+--
+--  GHDL is distributed in the hope that it will be useful, but WITHOUT ANY
+--  WARRANTY; without even the implied warranty of MERCHANTABILITY or
+--  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+--  for more details.
+--
+--  You should have received a copy of the GNU General Public License
+--  along with GCC; see the file COPYING2.  If not see
+--  <http://www.gnu.org/licenses/>.
+
+use std.textio.all;
+
+package std_logic_1164 is
+
+  --  Unresolved logic state.
+  type std_ulogic is
+    (
+     'U',  --  Uninitialized, this is also the default value.
+     'X',  --  Unknown / conflict value (forcing level).
+     '0',  --  0 (forcing level).
+     '1',  --  1 (forcing level).
+     'Z',  --  High impedance.
+     'W',  --  Unknown / conflict (weak level).
+     'L',  --  0 (weak level).
+     'H',  --  1 (weak level).
+     '-'   --  Don't care.
+    );
+
+  --  Vector of logic state.
+  type std_ulogic_vector is array (natural range <>) of std_ulogic;
+
+  --  Resolution function.
+  --  If S is empty, returns 'Z'.
+  --  If S has one element, return the element.
+  --  Otherwise, 'U' is the strongest.
+  --       then  'X'
+  --       then  '0' and '1'
+  --       then  'W'
+  --       then  'H' and 'L'
+  --       then  'Z'.
+  function resolved (s : std_ulogic_vector) return std_ulogic;
+
+  --  Resolved logic state.
+  subtype std_logic is resolved std_ulogic;
+
+  --  Vector of std_logic.
+  subtype std_logic_vector is (resolved) std_ulogic_vector;
+
+  --  Subtypes of std_ulogic.  The names give the values.
+  subtype X01   is resolved std_ulogic range 'X' to '1';
+  subtype X01Z  is resolved std_ulogic range 'X' to 'Z';
+  subtype UX01  is resolved std_ulogic range 'U' to '1';
+  subtype UX01Z is resolved std_ulogic range 'U' to 'Z';
+
+  --  Logical operators.
+  --  For logical operations, the inputs are first normalized to UX01:
+  --  0 and L are normalized to 0, 1 and 1 are normalized to 1, U isnt changed,
+  --  all other states are normalized to X.
+  --  Then the classical electric rules are followed.
+  function "and"  (l : std_ulogic; r : std_ulogic) return UX01;
+  function "nand" (l : std_ulogic; r : std_ulogic) return UX01;
+  function "or"   (l : std_ulogic; r : std_ulogic) return UX01;
+  function "nor"  (l : std_ulogic; r : std_ulogic) return UX01;
+  function "xor"  (l : std_ulogic; r : std_ulogic) return UX01;
+  function "xnor" (l : std_ulogic; r : std_ulogic) return UX01;
+  function "not"  (l : std_ulogic) return UX01;
+
+  --  Logical operators for vectors.
+  --  An assertion of severity failure fails if the length of L and R aren't
+  --  equal.  The result range is 1 to L'Length.
+
+  function "and"  (l, r : std_ulogic_vector) return std_ulogic_vector;
+  function "nand" (l, r : std_ulogic_vector) return std_ulogic_vector;
+  function "or"   (l, r : std_ulogic_vector) return std_ulogic_vector;
+  function "nor"  (l, r : std_ulogic_vector) return std_ulogic_vector;
+  function "xor"  (l, r : std_ulogic_vector) return std_ulogic_vector;
+  function "xnor" (l, r : std_ulogic_vector) return std_ulogic_vector;
+  function "not"  (l : std_ulogic_vector) return std_ulogic_vector;
+
+  function "and"  (l : std_ulogic_vector; r : std_ulogic       )
+    return std_ulogic_vector;
+  function "and"  (l : std_ulogic;        r : std_ulogic_vector)
+    return std_ulogic_vector;
+  function "nand" (l : std_ulogic_vector; r : std_ulogic       )
+    return std_ulogic_vector;
+  function "nand" (l : std_ulogic;        r : std_ulogic_vector)
+    return std_ulogic_vector;
+  function "or"   (l : std_ulogic_vector; r : std_ulogic       )
+    return std_ulogic_vector;
+  function "or"   (l : std_ulogic;        r : std_ulogic_vector)
+    return std_ulogic_vector;
+  function "nor"  (l : std_ulogic_vector; r : std_ulogic       )
+    return std_ulogic_vector;
+  function "nor"  (l : std_ulogic;        r : std_ulogic_vector)
+    return std_ulogic_vector;
+  function "xor"  (l : std_ulogic_vector; r : std_ulogic       )
+    return std_ulogic_vector;
+  function "xor"  (l : std_ulogic;        r : std_ulogic_vector)
+    return std_ulogic_vector;
+  function "xnor" (l : std_ulogic_vector; r : std_ulogic       )
+    return std_ulogic_vector;
+  function "xnor" (l : std_ulogic;        r : std_ulogic_vector)
+    return std_ulogic_vector;
+
+  function "and"  (l : std_ulogic_vector) return std_ulogic;
+  function "nand" (l : std_ulogic_vector) return std_ulogic;
+  function "or"   (l : std_ulogic_vector) return std_ulogic;
+  function "nor"  (l : std_ulogic_vector) return std_ulogic;
+  function "xor"  (l : std_ulogic_vector) return std_ulogic;
+  function "xnor" (l : std_ulogic_vector) return std_ulogic;
+
+  function "sll"  (l : std_ulogic_vector; r : integer)
+    return std_ulogic_vector;
+  function "srl"  (l : std_ulogic_vector; r : integer)
+    return std_ulogic_vector;
+  function "rol"  (l : std_ulogic_vector; r : integer)
+    return std_ulogic_vector;
+  function "ror"  (l : std_ulogic_vector; r : integer)
+    return std_ulogic_vector;
+
+  --  Conversion functions.
+  --  The result range (for vectors) is S'Length - 1 downto 0.
+  --  XMAP is return for values not in '0', '1', 'L', 'H'.
+  function to_bit (s : std_ulogic; xmap : bit := '0') return bit;
+  function to_bitvector (s : std_ulogic_vector; xmap : bit := '0')
+    return bit_vector;
+
+  function to_stdulogic (b : bit) return std_ulogic;
+  function to_stdlogicvector (b : bit_vector) return std_logic_vector;
+  function to_stdlogicvector (s : std_ulogic_vector) return std_logic_vector;
+  function to_stdulogicvector (b : bit_vector) return std_ulogic_vector;
+  function to_stdulogicvector (s : std_logic_vector) return std_ulogic_vector;
+
+  alias to_bit_vector is
+    to_bitvector[std_ulogic_vector, bit return bit_vector];
+  alias to_bv is
+    to_bitvector[std_ulogic_vector, bit return bit_vector];
+
+  alias to_std_logic_vector is
+    to_stdlogicvector[bit_vector return std_logic_vector];
+  alias to_slv is
+    to_stdlogicvector[bit_vector return std_logic_vector];
+
+  alias to_std_logic_vector is
+    to_stdlogicvector[std_ulogic_vector return std_logic_vector];
+  alias to_slv is
+    to_stdlogicvector[std_ulogic_vector return std_logic_vector];
+
+  alias to_std_ulogic_vector is
+    to_stdulogicvector[bit_vector return std_ulogic_vector];
+  alias to_sulv is
+    to_stdulogicvector[bit_vector return std_ulogic_vector];
+
+  alias to_std_ulogic_vector is
+    to_stdulogicvector[std_logic_vector return std_ulogic_vector];
+  alias to_sulv is
+    to_stdulogicvector[std_logic_vector return std_ulogic_vector];
+
+  --  Normalization.
+  --  The result range (for vectors) is 1 to S'Length.
+  function to_01  (s : std_ulogic_vector; xmap : std_ulogic := '0')
+    return std_ulogic_vector;
+  function to_01  (s : std_ulogic;        xmap : std_ulogic := '0')
+    return std_ulogic;
+  function to_01  (s : bit_vector;        xmap : std_ulogic := '0')
+    return std_ulogic_vector;
+  function to_01  (s : bit;               xmap : std_ulogic := '0')
+    return std_ulogic;
+
+  function to_X01 (s : std_ulogic_vector) return std_ulogic_vector;
+  function to_X01 (s : std_ulogic) return X01;
+  function to_X01 (b : bit_vector) return std_ulogic_vector;
+  function to_X01 (b : bit) return X01;
+
+  function to_X01Z (s : std_ulogic_vector) return std_ulogic_vector;
+  function to_X01Z (s : std_ulogic) return X01Z;
+  function to_X01Z (b : bit_vector) return std_ulogic_vector;
+  function to_X01Z (b : bit) return X01Z;
+
+  function to_UX01 (s : std_ulogic_vector) return std_ulogic_vector;
+  function to_UX01 (s : std_ulogic) return UX01;
+  function to_UX01 (b : bit_vector) return std_ulogic_vector;
+  function to_UX01 (b : bit) return UX01;
+
+  function "??" (l : std_ulogic) return boolean;
+
+  --  Edge detection.
+  --  An edge is detected in case of event on s, and X01 normalized value
+  --  rises from 0 to 1 or falls from 1 to 0.
+  function rising_edge (signal s : std_ulogic) return boolean;
+  function falling_edge (signal s : std_ulogic) return boolean;
+
+  --  Test for unknown.  Only 0, 1, L and H are known values.
+  function is_X (s : std_ulogic_vector) return boolean;
+  function is_X (s : std_ulogic) return boolean;
+
+  --  String conversion
+
+  alias to_bstring is to_string [std_ulogic_vector return string];
+  alias to_binary_string is to_string [std_ulogic_vector return string];
+
+  function to_ostring (value : std_ulogic_vector) return string;
+  alias to_octal_string is to_ostring [std_ulogic_vector return string];
+
+  function to_hstring (value : std_ulogic_vector) return string;
+  alias to_hex_string is to_hstring [std_ulogic_vector return string];
+
+  --  Input/output
+
+  procedure write (l : inout line; value : std_ulogic;
+                   justified : side := right; field : width := 0);
+
+  procedure write (l : inout line; value : std_ulogic_vector;
+                   justified : side := right; field : width := 0);
+  alias bwrite is write [line, std_ulogic_vector, side, width];
+  alias binary_write is write [line, std_ulogic_vector, side, width];
+
+  procedure owrite (l : inout line; value : std_ulogic_vector;
+                    justified : side := right; field : width := 0);
+  alias octal_write is owrite [line, std_ulogic_vector, side, width];
+
+  procedure hwrite (l : inout line; value : std_ulogic_vector;
+                    justified : side := right; field : width := 0);
+  alias hex_write is hwrite [line, std_ulogic_vector, side, width];
+
+  procedure read (l : inout line;
+                  value : out std_ulogic; good : out boolean);
+  procedure read (l : inout line; value : out std_ulogic);
+
+  procedure read (l : inout line;
+                  value : out std_ulogic_vector; good : out boolean);
+  procedure read (l : inout line; value : out std_ulogic_vector);
+  alias bread is read [line, std_ulogic_vector, boolean];
+  alias bread is read [line, std_ulogic_vector];
+  alias binary_read is read [line, std_ulogic_vector, boolean];
+  alias binary_read is read [line, std_ulogic_vector];
+
+  procedure hread (l : inout line;
+                   value : out std_ulogic_vector; good : out boolean);
+  procedure hread (l : inout line; value : out std_ulogic_vector);
+  alias hex_read is read [line, std_ulogic_vector, boolean];
+  alias hex_read is read [line, std_ulogic_vector];
+
+  procedure oread (l : inout line;
+                   value : out std_ulogic_vector; good : out boolean);
+  procedure oread (l : inout line; value : out std_ulogic_vector);
+  alias octal_read is read [line, std_ulogic_vector, boolean];
+  alias octal_read is read [line, std_ulogic_vector];
+end std_logic_1164;
diff --git a/libraries/openieee/std_logic_1164.v87 b/libraries/openieee/std_logic_1164.v87
index 1dc5252fd..67e63dac5 100644
--- a/libraries/openieee/std_logic_1164.v87
+++ b/libraries/openieee/std_logic_1164.v87
@@ -1,5 +1,5 @@
---  This is an implementation of ieee.std_logic_1164 based only on the
---  specifications.  This file is part of GHDL.
+--  This is an implementation of -*- vhdl -*- ieee.std_logic_1164 based only
+--  on the specifications.  This file is part of GHDL.
 --  Copyright (C) 2015 Tristan Gingold
 --
 --  GHDL is free software; you can redistribute it and/or modify it under
diff --git a/libraries/openieee/std_logic_1164.v93 b/libraries/openieee/std_logic_1164.v93
index 876733977..879a7870b 100644
--- a/libraries/openieee/std_logic_1164.v93
+++ b/libraries/openieee/std_logic_1164.v93
@@ -1,5 +1,5 @@
---  This is an implementation of ieee.std_logic_1164 based only on the
---  specifications.  This file is part of GHDL.
+--  This is an implementation of -*- vhdl -*- ieee.std_logic_1164 based only
+--  on the specifications.  This file is part of GHDL.
 --  Copyright (C) 2015 Tristan Gingold
 --
 --  GHDL is free software; you can redistribute it and/or modify it under
diff --git a/libraries/openieee/std_logic_1164.vhdl b/libraries/openieee/std_logic_1164.vhdl
index 6dec5b3fb..f5828ec6e 100644
--- a/libraries/openieee/std_logic_1164.vhdl
+++ b/libraries/openieee/std_logic_1164.vhdl
@@ -1,5 +1,5 @@
---  This is an implementation of ieee.std_logic_1164 based only on the
---  specifications.  This file is part of GHDL.
+--  This is an implementation of -*- vhdl -*- ieee.std_logic_1164 based only
+--  on the specifications.  This file is part of GHDL.
 --  Copyright (C) 2015 Tristan Gingold
 --
 --  GHDL is free software; you can redistribute it and/or modify it under
@@ -16,6 +16,8 @@
 --  along with GCC; see the file COPYING2.  If not see
 --  <http://www.gnu.org/licenses/>.
 
+use std.textio.all;   --V08
+                      --V08
 package std_logic_1164 is
 
   --  Unresolved logic state.
@@ -216,4 +218,57 @@ package std_logic_1164 is
   function is_X (s : std_ulogic_vector) return boolean;
   function is_X (s : std_logic_vector) return boolean;                --!V08
   function is_X (s : std_ulogic) return boolean;
+                                                                         --V08
+  --  String conversion                                                  --V08
+                                                                         --V08
+  alias to_bstring is to_string [std_ulogic_vector return string];       --V08
+  alias to_binary_string is to_string [std_ulogic_vector return string]; --V08
+                                                                         --V08
+  function to_ostring (value : std_ulogic_vector) return string;         --V08
+  alias to_octal_string is to_ostring [std_ulogic_vector return string]; --V08
+                                                                         --V08
+  function to_hstring (value : std_ulogic_vector) return string;         --V08
+  alias to_hex_string is to_hstring [std_ulogic_vector return string];   --V08
+                                                                         --V08
+  --  Input/output                                                       --V08
+                                                                         --V08
+  procedure write (l : inout line; value : std_ulogic;                   --V08
+                   justified : side := right; field : width := 0);       --V08
+                                                                         --V08
+  procedure write (l : inout line; value : std_ulogic_vector;            --V08
+                   justified : side := right; field : width := 0);       --V08
+  alias bwrite is write [line, std_ulogic_vector, side, width];          --V08
+  alias binary_write is write [line, std_ulogic_vector, side, width];    --V08
+                                                                         --V08
+  procedure owrite (l : inout line; value : std_ulogic_vector;           --V08
+                    justified : side := right; field : width := 0);      --V08
+  alias octal_write is owrite [line, std_ulogic_vector, side, width];    --V08
+                                                                         --V08
+  procedure hwrite (l : inout line; value : std_ulogic_vector;           --V08
+                    justified : side := right; field : width := 0);      --V08
+  alias hex_write is hwrite [line, std_ulogic_vector, side, width];      --V08
+                                                                         --V08
+  procedure read (l : inout line;                                        --V08
+                  value : out std_ulogic; good : out boolean);           --V08
+  procedure read (l : inout line; value : out std_ulogic);               --V08
+                                                                         --V08
+  procedure read (l : inout line;                                        --V08
+                  value : out std_ulogic_vector; good : out boolean);    --V08
+  procedure read (l : inout line; value : out std_ulogic_vector);        --V08
+  alias bread is read [line, std_ulogic_vector, boolean];                --V08
+  alias bread is read [line, std_ulogic_vector];                         --V08
+  alias binary_read is read [line, std_ulogic_vector, boolean];          --V08
+  alias binary_read is read [line, std_ulogic_vector];                   --V08
+                                                                         --V08
+  procedure hread (l : inout line;                                       --V08
+                   value : out std_ulogic_vector; good : out boolean);   --V08
+  procedure hread (l : inout line; value : out std_ulogic_vector);       --V08
+  alias hex_read is read [line, std_ulogic_vector, boolean];             --V08
+  alias hex_read is read [line, std_ulogic_vector];                      --V08
+                                                                         --V08
+  procedure oread (l : inout line;                                       --V08
+                   value : out std_ulogic_vector; good : out boolean);   --V08
+  procedure oread (l : inout line; value : out std_ulogic_vector);       --V08
+  alias octal_read is read [line, std_ulogic_vector, boolean];           --V08
+  alias octal_read is read [line, std_ulogic_vector];                    --V08
 end std_logic_1164;