FreeChainXenon/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

atomicity.h: Corrected for RTEMS targets which do not have a CAS instruction.

Browse source 
2001-02-14	Joel Sherrill <joel@OARcorp.com>

	* config/cpu/m68k/bits/atomicity.h: Corrected for RTEMS targets which
	do not have a CAS instruction.

From-SVN: r49772
This commit is contained in:
Joel Sherrill 2002-02-14 18:57:38 +00:00 • committed by Joel Sherrill
parent e62d89a165
commit 0b46224d2b
2 changed files with 32 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
libstdc++-v3/ChangeLog
View file

@ -1,3 +1,8 @@
2001-02-14 Joel Sherrill <joel@OARcorp.com>
* config/cpu/m68k/bits/atomicity.h: Corrected for RTEMS targets which
do not have a CAS instruction.
2002-02-14 Phil Edwards <pme@gcc.gnu.org>
* acinclude.m4 (GLIBCPP_ENABLE_SYMVERS): New macro, initial revision.

32
libstdc++-v3/config/cpu/m68k/bits/atomicity.h
View file

@ -52,6 +52,28 @@ __exchange_and_add (volatile _Atomic_word *__mem, int __val)
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.
*/
static inline _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;
}
#elif !defined(__mcf5200__) && !defined(__mcf5300__)
// 68000, 68010, cpu32 and 5400 support test-and-set.
@ -84,12 +106,10 @@ __exchange_and_add (volatile _Atomic_word *__mem, int __val)
return __result;
}
#else
// These variants do not support any atomic operations at all.
#elif defined(__vxWorks__) || defined(__embedded__)
// The best we can hope for is to disable interrupts, which we
// can only do from supervisor mode.
#if defined(__rtems__) || defined(__vxWorks__) || defined(__embedded__)
static inline _Atomic_word
__attribute__ ((__unused__))
__exchange_and_add (volatile _Atomic_word *__mem, int __val)
@ -106,7 +126,10 @@ __exchange_and_add (volatile _Atomic_word *__mem, int __val)
return __result;
}
#else
// These variants do not support any atomic operations at all.
#warning "__exchange_and_add is not atomic for this target"
static inline _Atomic_word
@ -121,8 +144,7 @@ __exchange_and_add (volatile _Atomic_word *__mem, int __val)
return __result;
}
#endif /* embedded */
#endif /* CAS / TAS / IRQ */
#endif /* CAS / IRQ / TAS */
static inline void
__attribute__ ((__unused__))