1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- I N T E R F A C E S . P A C K E D _ D E C I M A L --
8 -- (Version for IBM Mainframe Packed Decimal Format) --
10 -- Copyright (C) 1992-2001, Free Software Foundation, Inc. --
12 -- GNAT is free software; you can redistribute it and/or modify it under --
13 -- terms of the GNU General Public License as published by the Free Soft- --
14 -- ware Foundation; either version 2, or (at your option) any later ver- --
15 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
16 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
17 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
18 -- for more details. You should have received a copy of the GNU General --
19 -- Public License distributed with GNAT; see file COPYING. If not, write --
20 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
21 -- MA 02111-1307, USA. --
23 -- As a special exception, if other files instantiate generics from this --
24 -- unit, or you link this unit with other files to produce an executable, --
25 -- this unit does not by itself cause the resulting executable to be --
26 -- covered by the GNU General Public License. This exception does not --
27 -- however invalidate any other reasons why the executable file might be --
28 -- covered by the GNU Public License. --
30 -- GNAT was originally developed by the GNAT team at New York University. --
31 -- Extensive contributions were provided by Ada Core Technologies Inc. --
33 ------------------------------------------------------------------------------
35 with System; use System;
36 with Unchecked_Conversion;
38 package body Interfaces.Packed_Decimal is
40 type Packed is array (Byte_Length) of Unsigned_8;
41 -- The type used internally to represent packed decimal
43 type Packed_Ptr is access Packed;
44 function To_Packed_Ptr is new Unchecked_Conversion (Address, Packed_Ptr);
46 -- The following array is used to convert a value in the range 0-99 to
47 -- a packed decimal format with two hexadecimal nibbles. It is worth
48 -- using table look up in this direction because divides are expensive.
50 Packed_Byte : constant array (00 .. 99) of Unsigned_8 :=
51 (16#00#, 16#01#, 16#02#, 16#03#, 16#04#,
52 16#05#, 16#06#, 16#07#, 16#08#, 16#09#,
53 16#10#, 16#11#, 16#12#, 16#13#, 16#14#,
54 16#15#, 16#16#, 16#17#, 16#18#, 16#19#,
55 16#20#, 16#21#, 16#22#, 16#23#, 16#24#,
56 16#25#, 16#26#, 16#27#, 16#28#, 16#29#,
57 16#30#, 16#31#, 16#32#, 16#33#, 16#34#,
58 16#35#, 16#36#, 16#37#, 16#38#, 16#39#,
59 16#40#, 16#41#, 16#42#, 16#43#, 16#44#,
60 16#45#, 16#46#, 16#47#, 16#48#, 16#49#,
61 16#50#, 16#51#, 16#52#, 16#53#, 16#54#,
62 16#55#, 16#56#, 16#57#, 16#58#, 16#59#,
63 16#60#, 16#61#, 16#62#, 16#63#, 16#64#,
64 16#65#, 16#66#, 16#67#, 16#68#, 16#69#,
65 16#70#, 16#71#, 16#72#, 16#73#, 16#74#,
66 16#75#, 16#76#, 16#77#, 16#78#, 16#79#,
67 16#80#, 16#81#, 16#82#, 16#83#, 16#84#,
68 16#85#, 16#86#, 16#87#, 16#88#, 16#89#,
69 16#90#, 16#91#, 16#92#, 16#93#, 16#94#,
70 16#95#, 16#96#, 16#97#, 16#98#, 16#99#);
76 procedure Int32_To_Packed (V : Integer_32; P : System.Address; D : D32) is
77 PP : constant Packed_Ptr := To_Packed_Ptr (P);
78 Empty_Nibble : constant Boolean := ((D rem 2) = 0);
79 B : constant Byte_Length := (D / 2) + 1;
83 -- Deal with sign byte first
86 PP (B) := Unsigned_8 (VV rem 10) * 16 + 16#C#;
91 PP (B) := Unsigned_8 (VV rem 10) * 16 + 16#D#;
94 for J in reverse B - 1 .. 2 loop
103 PP (J) := Packed_Byte (Integer (VV rem 100));
108 -- Deal with leading byte
112 raise Constraint_Error;
114 PP (1) := Unsigned_8 (VV);
119 raise Constraint_Error;
121 PP (1) := Packed_Byte (Integer (VV));
127 ---------------------
128 -- Int64_To_Packed --
129 ---------------------
131 procedure Int64_To_Packed (V : Integer_64; P : System.Address; D : D64) is
132 PP : constant Packed_Ptr := To_Packed_Ptr (P);
133 Empty_Nibble : constant Boolean := ((D rem 2) = 0);
134 B : constant Byte_Length := (D / 2) + 1;
135 VV : Integer_64 := V;
138 -- Deal with sign byte first
141 PP (B) := Unsigned_8 (VV rem 10) * 16 + 16#C#;
146 PP (B) := Unsigned_8 (VV rem 10) * 16 + 16#D#;
149 for J in reverse B - 1 .. 2 loop
158 PP (J) := Packed_Byte (Integer (VV rem 100));
163 -- Deal with leading byte
167 raise Constraint_Error;
169 PP (1) := Unsigned_8 (VV);
174 raise Constraint_Error;
176 PP (1) := Packed_Byte (Integer (VV));
182 ---------------------
183 -- Packed_To_Int32 --
184 ---------------------
186 function Packed_To_Int32 (P : System.Address; D : D32) return Integer_32 is
187 PP : constant Packed_Ptr := To_Packed_Ptr (P);
188 Empty_Nibble : constant Boolean := ((D mod 2) = 0);
189 B : constant Byte_Length := (D / 2) + 1;
196 -- Cases where there is an unused (zero) nibble in the first byte.
197 -- Deal with the single digit nibble at the right of this byte
200 V := Integer_32 (PP (1));
204 raise Constraint_Error;
207 -- Cases where all nibbles are used
214 -- Loop to process bytes containing two digit nibbles
217 Dig := Shift_Right (PP (J), 4);
220 raise Constraint_Error;
222 V := V * 10 + Integer_32 (Dig);
225 Dig := PP (J) and 16#0F#;
228 raise Constraint_Error;
230 V := V * 10 + Integer_32 (Dig);
236 -- Deal with digit nibble in sign byte
238 Dig := Shift_Right (PP (J), 4);
241 raise Constraint_Error;
243 V := V * 10 + Integer_32 (Dig);
246 Sign := PP (J) and 16#0F#;
248 -- Process sign nibble (deal with most common cases first)
253 elsif Sign = 16#D# then
256 elsif Sign = 16#B# then
259 elsif Sign >= 16#A# then
263 raise Constraint_Error;
267 ---------------------
268 -- Packed_To_Int64 --
269 ---------------------
271 function Packed_To_Int64 (P : System.Address; D : D64) return Integer_64 is
272 PP : constant Packed_Ptr := To_Packed_Ptr (P);
273 Empty_Nibble : constant Boolean := ((D mod 2) = 0);
274 B : constant Byte_Length := (D / 2) + 1;
281 -- Cases where there is an unused (zero) nibble in the first byte.
282 -- Deal with the single digit nibble at the right of this byte
285 V := Integer_64 (PP (1));
289 raise Constraint_Error;
292 -- Cases where all nibbles are used
299 -- Loop to process bytes containing two digit nibbles
302 Dig := Shift_Right (PP (J), 4);
305 raise Constraint_Error;
307 V := V * 10 + Integer_64 (Dig);
310 Dig := PP (J) and 16#0F#;
313 raise Constraint_Error;
315 V := V * 10 + Integer_64 (Dig);
321 -- Deal with digit nibble in sign byte
323 Dig := Shift_Right (PP (J), 4);
326 raise Constraint_Error;
328 V := V * 10 + Integer_64 (Dig);
331 Sign := PP (J) and 16#0F#;
333 -- Process sign nibble (deal with most common cases first)
338 elsif Sign = 16#D# then
341 elsif Sign = 16#B# then
344 elsif Sign >= 16#A# then
348 raise Constraint_Error;
352 end Interfaces.Packed_Decimal;