gcc/ada/system-linux-x86_64.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                        GNAT RUN-TIME COMPONENTS                          --
   4 --                                                                          --
   5 --                               S Y S T E M                                --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                       (GNU-Linux/x86-64 Version)                         --
   9 --                                                                          --
  10 --          Copyright (C) 1992-2008, Free Software Foundation, Inc.         --
  11 --                                                                          --
  12 -- This specification is derived from the Ada Reference Manual for use with --
  13 -- GNAT. The copyright notice above, and the license provisions that follow --
  14 -- apply solely to the  contents of the part following the private keyword. --
  15 --                                                                          --
  16 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  17 -- terms of the  GNU General Public License as published  by the Free Soft- --
  18 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  19 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  20 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  21 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  22 -- for  more details.  You should have  received  a copy of the GNU General --
  23 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  24 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  25 -- Boston, MA 02110-1301, USA.                                              --
  26 --                                                                          --
  27 -- As a special exception,  if other files  instantiate  generics from this --
  28 -- unit, or you link  this unit with other files  to produce an executable, --
  29 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  30 -- covered  by the  GNU  General  Public  License.  This exception does not --
  31 -- however invalidate  any other reasons why  the executable file  might be --
  32 -- covered by the  GNU Public License.                                      --
  33 --                                                                          --
  34 -- GNAT was originally developed  by the GNAT team at  New York University. --
  35 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  36 --                                                                          --
  37 ------------------------------------------------------------------------------
  38
  39 package System is
  40    pragma Pure;
  41    --  Note that we take advantage of the implementation permission to make
  42    --  this unit Pure instead of Preelaborable; see RM 13.7.1(15). In Ada
  43    --  2005, this is Pure in any case (AI-362).
  44
  45    type Name is (SYSTEM_NAME_GNAT);
  46    System_Name : constant Name := SYSTEM_NAME_GNAT;
  47
  48    --  System-Dependent Named Numbers
  49
  50    Min_Int               : constant := Long_Long_Integer'First;
  51    Max_Int               : constant := Long_Long_Integer'Last;
  52
  53    Max_Binary_Modulus    : constant := 2 ** Long_Long_Integer'Size;
  54    Max_Nonbinary_Modulus : constant := 2 ** Integer'Size - 1;
  55
  56    Max_Base_Digits       : constant := Long_Long_Float'Digits;
  57    Max_Digits            : constant := Long_Long_Float'Digits;
  58
  59    Max_Mantissa          : constant := 63;
  60    Fine_Delta            : constant := 2.0 ** (-Max_Mantissa);
  61
  62    Tick                  : constant := 0.000_001;
  63
  64    --  Storage-related Declarations
  65
  66    type Address is private;
  67    pragma Preelaborable_Initialization (Address);
  68    Null_Address : constant Address;
  69
  70    Storage_Unit : constant := 8;
  71    Word_Size    : constant := 64;
  72    Memory_Size  : constant := 2 ** 64;
  73
  74    --  Address comparison
  75
  76    function "<"  (Left, Right : Address) return Boolean;
  77    function "<=" (Left, Right : Address) return Boolean;
  78    function ">"  (Left, Right : Address) return Boolean;
  79    function ">=" (Left, Right : Address) return Boolean;
  80    function "="  (Left, Right : Address) return Boolean;
  81
  82    pragma Import (Intrinsic, "<");
  83    pragma Import (Intrinsic, "<=");
  84    pragma Import (Intrinsic, ">");
  85    pragma Import (Intrinsic, ">=");
  86    pragma Import (Intrinsic, "=");
  87
  88    --  Other System-Dependent Declarations
  89
  90    type Bit_Order is (High_Order_First, Low_Order_First);
  91    Default_Bit_Order : constant Bit_Order := Low_Order_First;
  92    pragma Warnings (Off, Default_Bit_Order); -- kill constant condition warning
  93
  94    --  Priority-related Declarations (RM D.1)
  95
  96    --  0 .. 98 corresponds to the system priority range 1 .. 99.
  97    --
  98    --  If the scheduling policy is SCHED_FIFO or SCHED_RR the runtime makes use
  99    --  of the entire range provided by the system.
 100    --
 101    --  If the scheduling policy is SCHED_OTHER the only valid system priority
 102    --  is 1 and other values are simply ignored.
 103
 104    Max_Priority           : constant Positive := 97;
 105    Max_Interrupt_Priority : constant Positive := 98;
 106
 107    subtype Any_Priority       is Integer      range  0 .. 98;
 108    subtype Priority           is Any_Priority range  0 .. 97;
 109    subtype Interrupt_Priority is Any_Priority range 98 .. 98;
 110
 111    Default_Priority : constant Priority := 48;
 112
 113 private
 114
 115    type Address is mod Memory_Size;
 116    Null_Address : constant Address := 0;
 117
 118    --------------------------------------
 119    -- System Implementation Parameters --
 120    --------------------------------------
 121
 122    --  These parameters provide information about the target that is used
 123    --  by the compiler. They are in the private part of System, where they
 124    --  can be accessed using the special circuitry in the Targparm unit
 125    --  whose source should be consulted for more detailed descriptions
 126    --  of the individual switch values.
 127
 128    Backend_Divide_Checks     : constant Boolean := False;
 129    Backend_Overflow_Checks   : constant Boolean := False;
 130    Command_Line_Args         : constant Boolean := True;
 131    Configurable_Run_Time     : constant Boolean := False;
 132    Denorm                    : constant Boolean := True;
 133    Duration_32_Bits          : constant Boolean := False;
 134    Exit_Status_Supported     : constant Boolean := True;
 135    Fractional_Fixed_Ops      : constant Boolean := False;
 136    Frontend_Layout           : constant Boolean := False;
 137    Machine_Overflows         : constant Boolean := False;
 138    Machine_Rounds            : constant Boolean := True;
 139    Preallocated_Stacks       : constant Boolean := False;
 140    Signed_Zeros              : constant Boolean := True;
 141    Stack_Check_Default       : constant Boolean := False;
 142    Stack_Check_Probes        : constant Boolean := True;
 143    Stack_Check_Limits        : constant Boolean := False;
 144    Support_64_Bit_Divides    : constant Boolean := True;
 145    Support_Aggregates        : constant Boolean := True;
 146    Support_Composite_Assign  : constant Boolean := True;
 147    Support_Composite_Compare : constant Boolean := True;
 148    Support_Long_Shifts       : constant Boolean := True;
 149    Always_Compatible_Rep     : constant Boolean := False;
 150    Suppress_Standard_Library : constant Boolean := False;
 151    Use_Ada_Main_Program_Name : constant Boolean := False;
 152    ZCX_By_Default            : constant Boolean := True;
 153    GCC_ZCX_Support           : constant Boolean := True;
 154
 155 end System;