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diff --git a/gcc/ada/i-pacdec.ads b/gcc/ada/i-pacdec.ads new file mode 100644 index 00000000000..79f1e0db7c0 --- /dev/null +++ b/gcc/ada/i-pacdec.ads @@ -0,0 +1,152 @@ +------------------------------------------------------------------------------ +-- -- +-- 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 -- +-- -- +-- S p e c -- +-- (Version for IBM Mainframe Packed Decimal Format) -- +-- -- +-- $Revision: 1.4 $ -- +-- -- +-- Copyright (C) 1992,1993,1994,1995 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). -- +-- -- + +-- This unit defines the packed decimal format used by GNAT in response to +-- a specication of Machine_Radix 10 for a decimal fixed-point type. The +-- format and operations are completely encapsulated in this unit, so all +-- that is necessary to compile using different packed decimal formats is +-- to replace this single unit. + +-- Note that the compiler access the spec of this unit during compilation +-- to obtain the data length that needs allocating, so the correct version +-- of the spec must be available to the compiler, and must correspond to +-- the spec and body made available to the linker, and all units of a given +-- program must be compiled with the same version of the spec and body. +-- This consistency will be enforced automatically using the normal binder +-- consistency checking, since any unit declaring Machine_Radix 10 types or +-- containing operations on such data will implicitly with Packed_Decimal. + +with System; + +package Interfaces.Packed_Decimal is + + ------------------------ + -- Format Description -- + ------------------------ + + -- IBM Mainframe packed decimal format uses a byte string of length one + -- to 10 bytes, with the most significant byte first. Each byte contains + -- two decimal digits (with the high order digit in the left nibble, and + -- the low order four bits contain the sign, using the following code: + + -- 16#A# 2#1010# positive + -- 16#B# 2#1011# negative + -- 16#C# 2#1100# positive (preferred representation) + -- 16#D# 2#1101# negative (preferred representation) + -- 16#E# 2#1110# positive + -- 16#F# 2#1011# positive + + -- In this package, all six sign representations are interpreted as + -- shown above when an operand is read, when an operand is written, + -- the preferred representations are always used. Constraint_Error + -- is raised if any other bit pattern is found in the sign nibble, + -- or if a digit nibble contains an invalid digit code. + + -- Some examples follow: + + -- 05 76 3C +5763 + -- 00 01 1D -11 + -- 00 04 4E +44 (non-standard sign) + -- 00 00 00 invalid (incorrect sign nibble) + -- 0A 01 1C invalid (bad digit) + + ------------------ + -- Length Array -- + ------------------ + + -- The following array must be declared in exactly the form shown, since + -- the compiler accesses the associated tree to determine the size to be + -- allocated to a machine radix 10 type, depending on the number of digits. + + subtype Byte_Length is Positive range 1 .. 10; + -- Range of possible byte lengths + + Packed_Size : constant array (1 .. 18) of Byte_Length := + (01 => 01, -- Length in bytes for digits 1 + 02 => 02, -- Length in bytes for digits 2 + 03 => 02, -- Length in bytes for digits 2 + 04 => 03, -- Length in bytes for digits 2 + 05 => 03, -- Length in bytes for digits 2 + 06 => 04, -- Length in bytes for digits 2 + 07 => 04, -- Length in bytes for digits 2 + 08 => 05, -- Length in bytes for digits 2 + 09 => 05, -- Length in bytes for digits 2 + 10 => 06, -- Length in bytes for digits 2 + 11 => 06, -- Length in bytes for digits 2 + 12 => 07, -- Length in bytes for digits 2 + 13 => 07, -- Length in bytes for digits 2 + 14 => 08, -- Length in bytes for digits 2 + 15 => 08, -- Length in bytes for digits 2 + 16 => 09, -- Length in bytes for digits 2 + 17 => 09, -- Length in bytes for digits 2 + 18 => 10); -- Length in bytes for digits 2 + + ------------------------- + -- Conversion Routines -- + ------------------------- + + subtype D32 is Positive range 1 .. 9; + -- Used to represent number of digits in a packed decimal value that + -- can be represented in a 32-bit binary signed integer form. + + subtype D64 is Positive range 10 .. 18; + -- Used to represent number of digits in a packed decimal value that + -- requires a 64-bit signed binary integer for representing all values. + + function Packed_To_Int32 (P : System.Address; D : D32) return Integer_32; + -- The argument P is the address of a packed decimal value and D is the + -- number of digits (in the range 1 .. 9, as implied by the subtype). + -- The returned result is the corresponding signed binary value. The + -- exception Constraint_Error is raised if the input is invalid. + + function Packed_To_Int64 (P : System.Address; D : D64) return Integer_64; + -- The argument P is the address of a packed decimal value and D is the + -- number of digits (in the range 10 .. 18, as implied by the subtype). + -- The returned result is the corresponding signed binary value. The + -- exception Constraint_Error is raised if the input is invalid. + + procedure Int32_To_Packed (V : Integer_32; P : System.Address; D : D32); + -- The argument V is a signed binary integer, which is converted to + -- packed decimal format and stored using P, the address of a packed + -- decimal item of D digits (D is in the range 1-9). Constraint_Error + -- is raised if V is out of range of this number of digits. + + procedure Int64_To_Packed (V : Integer_64; P : System.Address; D : D64); + -- The argument V is a signed binary integer, which is converted to + -- packed decimal format and stored using P, the address of a packed + -- decimal item of D digits (D is in the range 10-18). Constraint_Error + -- is raised if V is out of range of this number of digits. + +end Interfaces.Packed_Decimal; |