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Diffstat (limited to 'gcc/ada/libgnat/s-atocou-x86.adb')
| -rw-r--r-- | gcc/ada/libgnat/s-atocou-x86.adb | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/gcc/ada/libgnat/s-atocou-x86.adb b/gcc/ada/libgnat/s-atocou-x86.adb new file mode 100644 index 00000000000..eb69a49e616 --- /dev/null +++ b/gcc/ada/libgnat/s-atocou-x86.adb @@ -0,0 +1,112 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT RUN-TIME COMPONENTS -- +-- -- +-- S Y S T E M . A T O M I C _ C O U N T E R S -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 2011-2017, 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 3, 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. -- +-- -- +-- As a special exception under Section 7 of GPL version 3, you are granted -- +-- additional permissions described in the GCC Runtime Library Exception, -- +-- version 3.1, as published by the Free Software Foundation. -- +-- -- +-- You should have received a copy of the GNU General Public License and -- +-- a copy of the GCC Runtime Library Exception along with this program; -- +-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- +-- <http://www.gnu.org/licenses/>. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +-- This implementation of the package for x86 processor. GCC can't generate +-- code for atomic builtins for 386 CPU. Only increment/decrement instructions +-- are supported, thus this implementaton uses machine code insertions to +-- access the necessary instructions. + +with System.Machine_Code; + +package body System.Atomic_Counters is + + -- Add comments showing in normal asm language what we generate??? + + --------------- + -- Decrement -- + --------------- + + function Decrement (Item : aliased in out Atomic_Unsigned) return Boolean is + Aux : Boolean; + + begin + System.Machine_Code.Asm + (Template => + "lock%; decl" & ASCII.HT & "%0" & ASCII.LF & ASCII.HT + & "sete %1", + Outputs => + (Atomic_Unsigned'Asm_Output ("=m", Item), + Boolean'Asm_Output ("=qm", Aux)), + Inputs => Atomic_Unsigned'Asm_Input ("m", Item), + Volatile => True); + + return Aux; + end Decrement; + + procedure Decrement (Item : aliased in out Atomic_Unsigned) is + begin + if Decrement (Item) then + null; + end if; + end Decrement; + + function Decrement (Item : in out Atomic_Counter) return Boolean is + begin + return Decrement (Item.Value); + end Decrement; + + --------------- + -- Increment -- + --------------- + + procedure Increment (Item : aliased in out Atomic_Unsigned) is + begin + System.Machine_Code.Asm + (Template => "lock%; incl" & ASCII.HT & "%0", + Outputs => Atomic_Unsigned'Asm_Output ("=m", Item), + Inputs => Atomic_Unsigned'Asm_Input ("m", Item), + Volatile => True); + end Increment; + + procedure Increment (Item : in out Atomic_Counter) is + begin + Increment (Item.Value); + end Increment; + + ---------------- + -- Initialize -- + ---------------- + + procedure Initialize (Item : out Atomic_Counter) is + begin + Item.Value := 1; + end Initialize; + + ------------ + -- Is_One -- + ------------ + + function Is_One (Item : Atomic_Counter) return Boolean is + begin + return Item.Value = 1; + end Is_One; + +end System.Atomic_Counters; |