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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- I N T E R F A C E S . P A C K E D _ D E C I M A L --
-- --
-- B o d y --
-- (Version for IBM Mainframe Packed Decimal Format) --
-- --
-- $Revision: 1.6 $
-- --
-- Copyright (C) 1992-2001, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 2, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT 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 distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
with System; use System;
with Unchecked_Conversion;
package body Interfaces.Packed_Decimal is
type Packed is array (Byte_Length) of Unsigned_8;
-- The type used internally to represent packed decimal
type Packed_Ptr is access Packed;
function To_Packed_Ptr is new Unchecked_Conversion (Address, Packed_Ptr);
-- The following array is used to convert a value in the range 0-99 to
-- a packed decimal format with two hexadecimal nibbles. It is worth
-- using table look up in this direction because divides are expensive.
Packed_Byte : constant array (00 .. 99) of Unsigned_8 :=
(16#00#, 16#01#, 16#02#, 16#03#, 16#04#,
16#05#, 16#06#, 16#07#, 16#08#, 16#09#,
16#10#, 16#11#, 16#12#, 16#13#, 16#14#,
16#15#, 16#16#, 16#17#, 16#18#, 16#19#,
16#20#, 16#21#, 16#22#, 16#23#, 16#24#,
16#25#, 16#26#, 16#27#, 16#28#, 16#29#,
16#30#, 16#31#, 16#32#, 16#33#, 16#34#,
16#35#, 16#36#, 16#37#, 16#38#, 16#39#,
16#40#, 16#41#, 16#42#, 16#43#, 16#44#,
16#45#, 16#46#, 16#47#, 16#48#, 16#49#,
16#50#, 16#51#, 16#52#, 16#53#, 16#54#,
16#55#, 16#56#, 16#57#, 16#58#, 16#59#,
16#60#, 16#61#, 16#62#, 16#63#, 16#64#,
16#65#, 16#66#, 16#67#, 16#68#, 16#69#,
16#70#, 16#71#, 16#72#, 16#73#, 16#74#,
16#75#, 16#76#, 16#77#, 16#78#, 16#79#,
16#80#, 16#81#, 16#82#, 16#83#, 16#84#,
16#85#, 16#86#, 16#87#, 16#88#, 16#89#,
16#90#, 16#91#, 16#92#, 16#93#, 16#94#,
16#95#, 16#96#, 16#97#, 16#98#, 16#99#);
---------------------
-- Int32_To_Packed --
---------------------
procedure Int32_To_Packed (V : Integer_32; P : System.Address; D : D32) is
PP : constant Packed_Ptr := To_Packed_Ptr (P);
Empty_Nibble : constant Boolean := ((D rem 2) = 0);
B : constant Byte_Length := (D / 2) + 1;
VV : Integer_32 := V;
begin
-- Deal with sign byte first
if VV >= 0 then
PP (B) := Unsigned_8 (VV rem 10) * 16 + 16#C#;
VV := VV / 10;
else
VV := -VV;
PP (B) := Unsigned_8 (VV rem 10) * 16 + 16#D#;
end if;
for J in reverse B - 1 .. 2 loop
if VV = 0 then
for K in 1 .. J loop
PP (K) := 16#00#;
end loop;
return;
else
PP (J) := Packed_Byte (Integer (VV rem 100));
VV := VV / 100;
end if;
end loop;
-- Deal with leading byte
if Empty_Nibble then
if VV > 9 then
raise Constraint_Error;
else
PP (1) := Unsigned_8 (VV);
end if;
else
if VV > 99 then
raise Constraint_Error;
else
PP (1) := Packed_Byte (Integer (VV));
end if;
end if;
end Int32_To_Packed;
---------------------
-- Int64_To_Packed --
---------------------
procedure Int64_To_Packed (V : Integer_64; P : System.Address; D : D64) is
PP : constant Packed_Ptr := To_Packed_Ptr (P);
Empty_Nibble : constant Boolean := ((D rem 2) = 0);
B : constant Byte_Length := (D / 2) + 1;
VV : Integer_64 := V;
begin
-- Deal with sign byte first
if VV >= 0 then
PP (B) := Unsigned_8 (VV rem 10) * 16 + 16#C#;
VV := VV / 10;
else
VV := -VV;
PP (B) := Unsigned_8 (VV rem 10) * 16 + 16#D#;
end if;
for J in reverse B - 1 .. 2 loop
if VV = 0 then
for K in 1 .. J loop
PP (K) := 16#00#;
end loop;
return;
else
PP (J) := Packed_Byte (Integer (VV rem 100));
VV := VV / 100;
end if;
end loop;
-- Deal with leading byte
if Empty_Nibble then
if VV > 9 then
raise Constraint_Error;
else
PP (1) := Unsigned_8 (VV);
end if;
else
if VV > 99 then
raise Constraint_Error;
else
PP (1) := Packed_Byte (Integer (VV));
end if;
end if;
end Int64_To_Packed;
---------------------
-- Packed_To_Int32 --
---------------------
function Packed_To_Int32 (P : System.Address; D : D32) return Integer_32 is
PP : constant Packed_Ptr := To_Packed_Ptr (P);
Empty_Nibble : constant Boolean := ((D mod 2) = 0);
B : constant Byte_Length := (D / 2) + 1;
V : Integer_32;
Dig : Unsigned_8;
Sign : Unsigned_8;
J : Positive;
begin
-- Cases where there is an unused (zero) nibble in the first byte.
-- Deal with the single digit nibble at the right of this byte
if Empty_Nibble then
V := Integer_32 (PP (1));
J := 2;
if V > 9 then
raise Constraint_Error;
end if;
-- Cases where all nibbles are used
else
J := 1;
end if;
-- Loop to process bytes containing two digit nibbles
while J < B loop
Dig := Shift_Right (PP (J), 4);
if Dig > 9 then
raise Constraint_Error;
else
V := V * 10 + Integer_32 (Dig);
end if;
Dig := PP (J) and 16#0F#;
if Dig > 9 then
raise Constraint_Error;
else
V := V * 10 + Integer_32 (Dig);
end if;
J := J + 1;
end loop;
-- Deal with digit nibble in sign byte
Dig := Shift_Right (PP (J), 4);
if Dig > 9 then
raise Constraint_Error;
else
V := V * 10 + Integer_32 (Dig);
end if;
Sign := PP (J) and 16#0F#;
-- Process sign nibble (deal with most common cases first)
if Sign = 16#C# then
return V;
elsif Sign = 16#D# then
return -V;
elsif Sign = 16#B# then
return -V;
elsif Sign >= 16#A# then
return V;
else
raise Constraint_Error;
end if;
end Packed_To_Int32;
---------------------
-- Packed_To_Int64 --
---------------------
function Packed_To_Int64 (P : System.Address; D : D64) return Integer_64 is
PP : constant Packed_Ptr := To_Packed_Ptr (P);
Empty_Nibble : constant Boolean := ((D mod 2) = 0);
B : constant Byte_Length := (D / 2) + 1;
V : Integer_64;
Dig : Unsigned_8;
Sign : Unsigned_8;
J : Positive;
begin
-- Cases where there is an unused (zero) nibble in the first byte.
-- Deal with the single digit nibble at the right of this byte
if Empty_Nibble then
V := Integer_64 (PP (1));
J := 2;
if V > 9 then
raise Constraint_Error;
end if;
-- Cases where all nibbles are used
else
J := 1;
end if;
-- Loop to process bytes containing two digit nibbles
while J < B loop
Dig := Shift_Right (PP (J), 4);
if Dig > 9 then
raise Constraint_Error;
else
V := V * 10 + Integer_64 (Dig);
end if;
Dig := PP (J) and 16#0F#;
if Dig > 9 then
raise Constraint_Error;
else
V := V * 10 + Integer_64 (Dig);
end if;
J := J + 1;
end loop;
-- Deal with digit nibble in sign byte
Dig := Shift_Right (PP (J), 4);
if Dig > 9 then
raise Constraint_Error;
else
V := V * 10 + Integer_64 (Dig);
end if;
Sign := PP (J) and 16#0F#;
-- Process sign nibble (deal with most common cases first)
if Sign = 16#C# then
return V;
elsif Sign = 16#D# then
return -V;
elsif Sign = 16#B# then
return -V;
elsif Sign >= 16#A# then
return V;
else
raise Constraint_Error;
end if;
end Packed_To_Int64;
end Interfaces.Packed_Decimal;
|
