tvl-depot/third_party/glog/m4/ac_have_builtin_expect.m4

14 lines
483 B
Text

AC_DEFUN([AX_C___BUILTIN_EXPECT], [
AC_MSG_CHECKING(for __builtin_expect)
AC_CACHE_VAL(ac_cv___builtin_expect, [
AC_TRY_COMPILE(
[int foo(void) { if (__builtin_expect(0, 0)) return 1; return 0; }],
[],
ac_cv___builtin_expect=yes,
ac_cv___builtin_expect=no
)])
if test "$ac_cv___builtin_expect" = "yes"; then
AC_DEFINE(HAVE___BUILTIN_EXPECT, 1, [define if your compiler has __builtin_expect])
fi
AC_MSG_RESULT($ac_cv___builtin_expect)
])