Import vests testsuite

1 files changed, 88 insertions, 0 deletions

diff --git a/testsuite/vests/vhdl-93/ashenden/compliant/ch_06_mult-b.vhd b/testsuite/vests/vhdl-93/ashenden/compliant/ch_06_mult-b.vhd
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+
+-- Copyright (C) 1996 Morgan Kaufmann Publishers, Inc
+
+-- This file is part of VESTs (Vhdl tESTs).
+
+-- VESTs 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 of the License, or (at
+-- your option) any later version. 
+
+-- VESTs 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 VESTs; if not, write to the Free Software Foundation,
+-- Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
+
+-- ---------------------------------------------------------------------
+--
+-- $Id: ch_06_mult-b.vhd,v 1.2 2001-10-26 16:29:34 paw Exp $
+-- $Revision: 1.2 $
+--
+-- ---------------------------------------------------------------------
+
+architecture behavioral of multiplier is
+begin
+
+  behavior : process (a, b) is
+
+                              constant Tpd_in_out : time := 40 ns;
+                            variable negative_result  : boolean;
+                            variable op1 : std_ulogic_vector(15 downto 0);
+                            variable op2 : std_ulogic_vector(15 downto 0);
+                            variable result : std_ulogic_vector(31 downto 0);
+                            variable carry_in, carry : std_ulogic;
+
+  begin
+    op1 := to_X01(a);
+    op2 := to_X01(b);
+    -- make both operands positive, remembering sign of result
+    negative_result := (op1(15) = '1') xor (op2(15) = '1');
+    if (op1(15) = '1') then
+      carry := '1';
+      for index in 0 to 15 loop
+        carry_in := carry;
+        carry := carry_in and not op1(index);
+        op1(index) := not op1(index) xor carry_in;
+      end loop;
+    end if;
+    if (op2(15) = '1') then
+      carry := '1';
+      for index in 0 to 15 loop
+        carry_in := carry;
+        carry := carry_in and not op2(index);
+        op2(index) := not op2(index) xor carry_in;
+      end loop;
+    end if;
+    -- do long multiplication
+    result := (others => '0');
+    for count in 0 to 15 loop
+      carry := '0';
+      if (op2(count) = '1') then
+        for index in 0 to 15 loop
+          carry_in := carry;
+          carry := (result(index+count) and op1(index))
+                   or (carry_in and (result(index+count) xor op1(index)));
+          result(index+count) := result(index+count) xor op1(index) xor carry_in;
+        end loop;
+        result(count+16) := carry;
+      end if;
+    end loop;
+    -- result now contains unsigned product, with binary point
+    -- between bits 30 and 29.  assign output with sign adjusted.
+    if negative_result then
+      carry := '1';
+      for index in 0 to 31 loop
+        carry_in := carry;
+        carry := carry_in and not result(index);
+        result(index) := not result(index) xor carry_in;
+      end loop;
+    end if;
+    p <= result after Tpd_in_out;
+  end process behavior;
+
+end architecture behavioral;
+