From: Richard Henderson Date: Mon, 13 Feb 2012 21:30:31 +0000 (-0800) Subject: PR libstdc++/51798 continued X-Git-Tag: releases/gcc-4.7.0~423 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b2cb69647e04765b87f0f1ba9f39b4a353574135;p=thirdparty%2Fgcc.git PR libstdc++/51798 continued PR libstdc++/51798 continued * include/bits/shared_ptr_base.h (_Sp_counted_base<_S_atomic>::_M_add_ref_lock): Hoist initial load outside compare_exchange loop. * include/tr1/shared_ptr.h: Same. * include/parallel/compatibility.h (__compare_and_swap_32): Use strong version of compare_exchange. (__compare_and_swap_64): Same. * include/profile/impl/profiler_state.h (__gnu_profile::__turn): Same. * libsupc++/guard.cc (__cxa_guard_acquire): Same. From-SVN: r184171 --- diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index af3f50af0eb3..723007cdfe01 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,16 @@ +2012-02-13 Richard Henderson + + PR libstdc++/51798 continued. + * include/bits/shared_ptr_base.h + (_Sp_counted_base<_S_atomic>::_M_add_ref_lock): Hoist initial load + outside compare_exchange loop. + * include/tr1/shared_ptr.h: Same. + * include/parallel/compatibility.h (__compare_and_swap_32): Use strong + version of compare_exchange. + (__compare_and_swap_64): Same. + * include/profile/impl/profiler_state.h (__gnu_profile::__turn): Same. + * libsupc++/guard.cc (__cxa_guard_acquire): Same. + 2012-02-10 Benjamin Kosnik Jonathan Wakely diff --git a/libstdc++-v3/include/bits/shared_ptr_base.h b/libstdc++-v3/include/bits/shared_ptr_base.h index ebdc7ed94525..c48c18eaee9b 100644 --- a/libstdc++-v3/include/bits/shared_ptr_base.h +++ b/libstdc++-v3/include/bits/shared_ptr_base.h @@ -236,13 +236,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION _M_add_ref_lock() { // Perform lock-free add-if-not-zero operation. - _Atomic_word __count; + _Atomic_word __count = _M_use_count; do { - __count = _M_use_count; if (__count == 0) __throw_bad_weak_ptr(); - // Replace the current counter value with the old value + 1, as // long as it's not changed meanwhile. } diff --git a/libstdc++-v3/include/parallel/compatibility.h b/libstdc++-v3/include/parallel/compatibility.h index 460345ef3994..ed75215ceaf1 100644 --- a/libstdc++-v3/include/parallel/compatibility.h +++ b/libstdc++-v3/include/parallel/compatibility.h @@ -252,8 +252,9 @@ namespace __gnu_parallel __replacement, __comparand) == __comparand; #elif defined(__GNUC__) - return __atomic_compare_exchange_n(__ptr, &__comparand, __replacement, true, - __ATOMIC_ACQ_REL, __ATOMIC_RELAXED); + return __atomic_compare_exchange_n(__ptr, &__comparand, __replacement, + false, __ATOMIC_ACQ_REL, + __ATOMIC_RELAXED); #elif defined(__SUNPRO_CC) && defined(__sparc) return atomic_cas_32((volatile unsigned int*)__ptr, __comparand, __replacement) == __comparand; @@ -299,13 +300,15 @@ namespace __gnu_parallel #endif #elif defined(__GNUC__) && defined(__x86_64) - return __atomic_compare_exchange_n(__ptr, &__comparand, __replacement, true, - __ATOMIC_ACQ_REL, __ATOMIC_RELAXED); + return __atomic_compare_exchange_n(__ptr, &__comparand, __replacement, + false, __ATOMIC_ACQ_REL, + __ATOMIC_RELAXED); #elif defined(__GNUC__) && defined(__i386) && \ (defined(__i686) || defined(__pentium4) || defined(__athlon) \ || defined(__k8) || defined(__core2)) - return __atomic_compare_exchange_n(__ptr, &__comparand, __replacement, true, - __ATOMIC_ACQ_REL, __ATOMIC_RELAXED); + return __atomic_compare_exchange_n(__ptr, &__comparand, __replacement, + false, __ATOMIC_ACQ_REL, + __ATOMIC_RELAXED); #elif defined(__SUNPRO_CC) && defined(__sparc) return atomic_cas_64((volatile unsigned long long*)__ptr, __comparand, __replacement) == __comparand; diff --git a/libstdc++-v3/include/profile/impl/profiler_state.h b/libstdc++-v3/include/profile/impl/profiler_state.h index 573aa0eeb403..d48801ab561a 100644 --- a/libstdc++-v3/include/profile/impl/profiler_state.h +++ b/libstdc++-v3/include/profile/impl/profiler_state.h @@ -48,7 +48,7 @@ namespace __gnu_profile { __state_type inv(__INVALID); return __atomic_compare_exchange_n(&_GLIBCXX_PROFILE_DATA(__state), - &inv, __s, true, __ATOMIC_ACQ_REL, + &inv, __s, false, __ATOMIC_ACQ_REL, __ATOMIC_RELAXED); } diff --git a/libstdc++-v3/include/tr1/shared_ptr.h b/libstdc++-v3/include/tr1/shared_ptr.h index 723e317646de..5a1eb038a38b 100644 --- a/libstdc++-v3/include/tr1/shared_ptr.h +++ b/libstdc++-v3/include/tr1/shared_ptr.h @@ -237,13 +237,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION _M_add_ref_lock() { // Perform lock-free add-if-not-zero operation. - _Atomic_word __count; + _Atomic_word __count = _M_use_count; do { - __count = _M_use_count; if (__count == 0) __throw_bad_weak_ptr(); - // Replace the current counter value with the old value + 1, as // long as it's not changed meanwhile. } diff --git a/libstdc++-v3/libsupc++/guard.cc b/libstdc++-v3/libsupc++/guard.cc index b7b8d3f855b8..adc960861081 100644 --- a/libstdc++-v3/libsupc++/guard.cc +++ b/libstdc++-v3/libsupc++/guard.cc @@ -251,8 +251,9 @@ namespace __cxxabiv1 while (1) { - if (__atomic_compare_exchange_n(gi, &expected, pending_bit, true, - __ATOMIC_ACQ_REL, __ATOMIC_RELAXED)) + if (__atomic_compare_exchange_n(gi, &expected, pending_bit, false, + __ATOMIC_ACQ_REL, + __ATOMIC_RELAXED)) { // This thread should do the initialization. return 1; @@ -266,7 +267,7 @@ namespace __cxxabiv1 if (expected == pending_bit) { int newv = expected | waiting_bit; - if (!__atomic_compare_exchange_n(gi, &expected, newv, true, + if (!__atomic_compare_exchange_n(gi, &expected, newv, false, __ATOMIC_ACQ_REL, __ATOMIC_RELAXED)) continue;