diff options
| -rw-r--r-- | libstdc++-v3/ChangeLog | 5 | ||||
| -rw-r--r-- | libstdc++-v3/config/cpu/m68k/bits/atomicity.h | 32 |
2 files changed, 32 insertions, 5 deletions
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index d970030..2015d51 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -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. diff --git a/libstdc++-v3/config/cpu/m68k/bits/atomicity.h b/libstdc++-v3/config/cpu/m68k/bits/atomicity.h index 0b8f4e8..c5d3394 100644 --- a/libstdc++-v3/config/cpu/m68k/bits/atomicity.h +++ b/libstdc++-v3/config/cpu/m68k/bits/atomicity.h @@ -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__)) |