Bugfix in gen_fill_mask_rom (wrong result on zero shift amounts due to width mismatch)

Committed on the Free edition of March Hare Software CVSNT Server.
Upgrade to CVS Suite for more features and support:
http://march-hare.com/cvsnt/


git-svn-id: http://moon:8086/svn/vhdl/trunk@509 cc03376c-175c-47c8-b038-4cd826a8556b

lib/CPUs/MIPS/src/core/mips_shifter.vhd

@@ -54,10 +54,12 @@ architecture Behavioral of shifter is
 function gen_fill_mask_rom(data_width : natural) return fill_mask_rom_t is
 	variable result : fill_mask_rom_t;
 	begin
-		for i in 0 to data_width-1 loop
+	    result(0) := (data_width-1 downto 0 => '0');
+		for i in 1 to data_width-1 loop
 			result(i) := (data_width-1-i downto 0 => '0') & (i-1 downto 0 => '1');
 		end loop;	
-		for i in 0 to data_width-1 loop
+	    result(data_width) := (data_width-1 downto 0 => '0');
+		for i in 1 to data_width-1 loop
 			result(data_width+i) := (i-1 downto 0 => '1') & (data_width-1-i downto 0 => '0');
 		end loop;	
 	return result;