Imported gcc-4.4.3

[msp430-gcc.git] / libstdc++-v3 / config / cpu / m68k / atomicity.h

diff --git a/libstdc++-v3/config/cpu/m68k/atomicity.h b/libstdc++-v3/config/cpu/m68k/atomicity.h
new file mode 100644 (file)
index 0000000..e6cdbee
--- /dev/null
+++ b/libstdc++-v3/config/cpu/m68k/atomicity.h
@@ -0,0 +1,129 @@
+// Low-level functions for atomic operations: m68k version -*- C++ -*-
+
+// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2009 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// 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/>.
+
+#include <ext/atomicity.h>
+
+_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
+
+#if ( defined(__mc68020__) || defined(__mc68030__) \
+      || defined(__mc68040__) || defined(__mc68060__) ) \
+    && !defined(__mcpu32__)
+  // These variants support compare-and-swap.
+  _Atomic_word 
+  __attribute__ ((__unused__))
+  __exchange_and_add(volatile _Atomic_word* __mem, int __val)
+  {
+    register _Atomic_word __result = *__mem;
+    register _Atomic_word __temp;
+    __asm__ __volatile__ ("1: move%.l %0,%1\n\t"
+                         "add%.l %3,%1\n\t"
+                         "cas%.l %0,%1,%2\n\t"
+                         "jne 1b"
+                         : "=d" (__result), "=&d" (__temp), "=m" (*__mem)
+                         : "d" (__val), "0" (__result), "m" (*__mem));
+    return __result;
+  }
+
+#elif defined(__rtems__)
+  // TAS/JBNE is unsafe on systems with strict priority-based scheduling.
+  // Disable interrupts, which we can do only from supervisor mode.
+  _Atomic_word
+  __attribute__ ((__unused__))
+  __exchange_and_add(volatile _Atomic_word* __mem, int __val)
+  {
+    _Atomic_word __result;
+    short __level, __tmpsr;
+    __asm__ __volatile__ ("move%.w %%sr,%0\n\tor%.l %0,%1\n\tmove%.w %1,%%sr"
+                         : "=d"(__level), "=d"(__tmpsr) : "1"(0x700));
+    
+    __result = *__mem;
+    *__mem = __result + __val;    
+    __asm__ __volatile__ ("move%.w %0,%%sr" : : "d"(__level));
+    
+    return __result;
+  }
+
+#else
+  
+  template<int __inst>
+    struct _Atomicity_lock
+    {
+      static volatile unsigned char _S_atomicity_lock;
+    };
+
+  template<int __inst>
+  volatile unsigned char _Atomicity_lock<__inst>::_S_atomicity_lock = 0;
+  
+  template volatile unsigned char _Atomicity_lock<0>::_S_atomicity_lock;
+  
+  _Atomic_word 
+  __attribute__ ((__unused__))
+  __exchange_and_add(volatile _Atomic_word* __mem, int __val)
+  {
+    _Atomic_word __result;
+    
+    // bset with no immediate addressing (not SMP-safe)
+#if defined(__mcfisaa__) || defined(__mcfisaaplus__)
+    __asm__ __volatile__("1: bset.b #7,%0@\n\tjbne 1b"
+                        : /* no outputs */
+                        : "a"(&_Atomicity_lock<0>::_S_atomicity_lock)
+                        : "cc", "memory");
+    
+    // CPU32 and CF ISAs B & C support test-and-set (SMP-safe).
+#elif defined(__mcpu32__) || defined(__mcfisab__) || defined (__mcfisac__)
+    __asm__ __volatile__("1: tas %0\n\tjbne 1b"
+                        : "+m"(_Atomicity_lock<0>::_S_atomicity_lock)
+                        : /* none */
+                        : "cc");
+    
+    // Use bset with immediate addressing for 68000/68010 (not SMP-safe)
+    // NOTE: TAS is available on the 68000, but unsupported by some Amiga
+    // memory controllers.
+#else
+    __asm__ __volatile__("1: bset.b #7,%0\n\tjbne 1b"
+                        : "+m"(_Atomicity_lock<0>::_S_atomicity_lock)
+                        : /* none */
+                        : "cc");
+#endif
+    
+    __result = *__mem;
+    *__mem = __result + __val;
+    
+    _Atomicity_lock<0>::_S_atomicity_lock = 0;
+    
+    return __result;
+  }
+  
+#endif /* TAS / BSET */
+
+  void
+  __attribute__ ((__unused__))
+  __atomic_add(volatile _Atomic_word* __mem, int __val)
+  {
+    // Careful: using add.l with a memory destination is not
+    // architecturally guaranteed to be atomic.
+    __exchange_and_add(__mem, __val);
+  }
+
+_GLIBCXX_END_NAMESPACE