Optimization Question

[dvdeug@my-deja.com]

I'm trying to write a program similar to the Unix utility strings, as my
copy of strings refuses to run a 17GB file. It seems to work, but it's
about 10x slower than strings, and rough calculations puts running time
on that 17GB file at 10 hours. I'm running the woody Debian version of
GNAT (3.13) on i686-linux-gnu, and I compiled the program with gnatmake
-g -gnatwa -gnatpn -Wall -W -O3 strings.adb. Is there anything I've
missed that speed this program a lot? (It's been run through gcov, so
the numbers up front are execution counts.)


		with Ada.Characters.Handling; use Ada.Characters.Handling;
		with Ada.Characters.Latin_1; use Ada.Characters.Latin_1;
		with Ada.Sequential_IO;
		with Ada.Command_Line; use Ada.Command_Line;
		with Ada.Text_IO;

           2    procedure Strings is

           1       type Byte is mod 2 ** 8;
		   package Byte_IO is new Ada.Sequential_IO (Byte);
		   use Byte_IO;

       56710       function String_Charp (A : Character) return Boolean
is
		   begin
       56710          return Is_ISO_646 (A) and then
		        (Is_Graphic (A) or else A = HT or else A = LF or else A = CR);
		   end String_Charp;
		   pragma Inline (String_Charp);

           1       Binary_File : File_Type;
           1       Letter_Buffer : String (1 .. 4);
		   subtype Buffer_Size is Integer range 0 .. 4;
           1       Letters_Found : Buffer_Size := 0;
           1       Current_Char : Byte;

           1       Seperating_String : constant String := (LF, NUL);

		begin
           1       if Argument_Count /= 1 then
      ######          Set_Exit_Status (1);
      ######          Ada.Text_IO.Put ("One file name only!");
      ######          return;
		   end if;

           1       Open (Binary_File, In_File, Argument(1));
       56711       loop
       56711          Read (Binary_File, Current_Char);

       56710          if String_Charp (Character'Val (Current_Char))
then
       29610             if Letters_Found < 4 then
        8453                Letters_Found := Letters_Found + 1;
        8453                Letter_Buffer (Letters_Found) :=
Character'Val (Current_Char);
        8453                if Letters_Found = 4 then
         916                   Ada.Text_IO.Put (Letter_Buffer);
		            end if;
		         else
       21157                Ada.Text_IO.Put (Character'Val
(Current_Char));
		         end if;
		      else
       27100             if Letters_Found = 4 then
         916                Ada.Text_IO.Put (Seperating_String);
		         end if;
       27100             Letters_Found := 0;
		      end if;
		   end loop;
      ######       Ada.Text_IO.Put ("Invalid end!");
      ######       Set_Exit_Status (2);
		exception
           1       when End_Error =>
           1          Close (Binary_File);
      ######       when others =>
      ######          raise;
		end Strings;



--
David Starner - dstarner98@aasaa.ofe.org


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