9d5507f7a2
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@50480 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
30 lines
933 B
Plaintext
30 lines
933 B
Plaintext
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dnl Checks for availability of GCC's atomic operations builtins.
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dnl Defines HAVE_GCC_ATOMIC_BUILTINS if available.
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AC_DEFUN([WX_ATOMIC_BUILTINS],
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[
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AC_REQUIRE([AC_PROG_CC])
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if test -n "$GCC"; then
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AC_MSG_CHECKING([for __sync_fetch_and_add and __sync_sub_and_fetch builtins])
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AC_CACHE_VAL(wx_cv_cc_gcc_atomic_builtins, [
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AC_TRY_LINK(
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[],
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[
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unsigned int value=0;
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/* wxAtomicInc doesn't use return value here */
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__sync_fetch_and_add(&value, 2);
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__sync_sub_and_fetch(&value, 1);
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/* but wxAtomicDec does, so mimic that: */
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unsigned int r2 = __sync_sub_and_fetch(&value, 1);
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],
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wx_cv_cc_gcc_atomic_builtins=yes,
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wx_cv_cc_gcc_atomic_builtins=no)
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])
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AC_MSG_RESULT([$wx_cv_cc_gcc_atomic_builtins])
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if test $wx_cv_cc_gcc_atomic_builtins = yes; then
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AC_DEFINE([HAVE_GCC_ATOMIC_BUILTINS])
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fi
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fi
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])
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