[Bug tree-optimization/102566] [i386] GCC should emit LOCK BTS for simple bit-test-and-set operations with std::atomic

[hjl.tools at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102566

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
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          Component|target                      |tree-optimization

--- Comment #3 from H.J. Lu <hjl.tools at gmail dot com> ---
optimize_atomic_bit_test_and works on

  _1 = __atomic_fetch_or_4 (&v, 1, 0);
  _4 = _1 & 1;

but fails on

  _1 = __atomic_fetch_or_4 (&v, 1, 0);
  _2 = (int) _1;
  _5 = _2 & 1;