+2015-09-17 Richard Henderson <rth@redhat.com>
+
+ PR libstdc++/65913
+ * builtins.c (fold_builtin_atomic_always_lock_free): Handle fake
+ pointers that encode the alignment of the object.
+
2015-09-17 Eric Botcazou <ebotcazou@adacore.com>
PR rtl-optimization/66790
mode = mode_for_size (size, MODE_INT, 0);
mode_align = GET_MODE_ALIGNMENT (mode);
- if (TREE_CODE (arg1) == INTEGER_CST && INTVAL (expand_normal (arg1)) == 0)
- type_align = mode_align;
+ if (TREE_CODE (arg1) == INTEGER_CST)
+ {
+ unsigned HOST_WIDE_INT val = UINTVAL (expand_normal (arg1));
+
+ /* Either this argument is null, or it's a fake pointer encoding
+ the alignment of the object. */
+ val = val & -val;
+ val *= BITS_PER_UNIT;
+
+ if (val == 0 || mode_align < val)
+ type_align = mode_align;
+ else
+ type_align = val;
+ }
else
{
tree ttype = TREE_TYPE (arg1);
2015-09-17 Jonathan Wakely <jwakely@redhat.com>
+ PR libstdc++/65913
+ * include/bits/atomic_base.h (__atomic_base<_TTp>::is_lock_free(),
+ __atomic_base<_PTp*>::is_lock_free()): Call the built-in with the
+ immediate pointer value, not a variable.
+ * include/std/atomic (atomic<T>::is_lock_free()): Likewise.
+ * testsuite/29_atomics/atomic/65913.cc: New.
+
* testsuite/experimental/filesystem/operations/canonical.cc: Remove
non-deterministic part of the test.
bool
is_lock_free() const noexcept
{
- // Produce a fake, minimally aligned pointer.
- void *__a = reinterpret_cast<void *>(-__alignof(_M_i));
- return __atomic_is_lock_free(sizeof(_M_i), __a);
+ // Use a fake, minimally aligned pointer.
+ return __atomic_is_lock_free(sizeof(_M_i),
+ reinterpret_cast<void *>(-__alignof(_M_i)));
}
bool
is_lock_free() const volatile noexcept
{
- // Produce a fake, minimally aligned pointer.
- void *__a = reinterpret_cast<void *>(-__alignof(_M_i));
- return __atomic_is_lock_free(sizeof(_M_i), __a);
+ // Use a fake, minimally aligned pointer.
+ return __atomic_is_lock_free(sizeof(_M_i),
+ reinterpret_cast<void *>(-__alignof(_M_i)));
}
_GLIBCXX_ALWAYS_INLINE void
is_lock_free() const noexcept
{
// Produce a fake, minimally aligned pointer.
- void *__a = reinterpret_cast<void *>(-__alignof(_M_p));
- return __atomic_is_lock_free(sizeof(_M_p), __a);
+ return __atomic_is_lock_free(sizeof(_M_p),
+ reinterpret_cast<void *>(-__alignof(_M_p)));
}
bool
is_lock_free() const volatile noexcept
{
// Produce a fake, minimally aligned pointer.
- void *__a = reinterpret_cast<void *>(-__alignof(_M_p));
- return __atomic_is_lock_free(sizeof(_M_p), __a);
+ return __atomic_is_lock_free(sizeof(_M_p),
+ reinterpret_cast<void *>(-__alignof(_M_p)));
}
_GLIBCXX_ALWAYS_INLINE void
is_lock_free() const noexcept
{
// Produce a fake, minimally aligned pointer.
- void *__a = reinterpret_cast<void *>(-__alignof(_M_i));
- return __atomic_is_lock_free(sizeof(_M_i), __a);
+ return __atomic_is_lock_free(sizeof(_M_i),
+ reinterpret_cast<void *>(-__alignof(_M_i)));
}
bool
is_lock_free() const volatile noexcept
{
// Produce a fake, minimally aligned pointer.
- void *__a = reinterpret_cast<void *>(-__alignof(_M_i));
- return __atomic_is_lock_free(sizeof(_M_i), __a);
+ return __atomic_is_lock_free(sizeof(_M_i),
+ reinterpret_cast<void *>(-__alignof(_M_i)));
}
void
--- /dev/null
+// Copyright (C) 2015 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.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-do run { target x86_64-*-linux* powerpc*-*-linux* } }
+// { dg-options "-std=gnu++11 -O0" }
+
+#include <atomic>
+#include <testsuite_hooks.h>
+
+// PR libstdc++/65913
+
+void
+test01()
+{
+ struct Int { int i; };
+ VERIFY( std::atomic<Int>{}.is_lock_free() );
+ VERIFY( std::atomic<int>{}.is_lock_free() );
+ VERIFY( std::atomic<int*>{}.is_lock_free() );
+}
+
+int
+main()
+{
+ test01();
+}