diff options
| author | Vincent Ambo <tazjin@google.com> | 2020-05-27T00·26+0100 |
|---|---|---|
| committer | Vincent Ambo <tazjin@google.com> | 2020-05-27T00·26+0100 |
| commit | afe04691aca3f669f517adaeb5bd4a87a481fb4a (patch) | |
| tree | 60ae6c91a3959b2f6486256e26ff126e598d1e5d /m4/ac_have_builtin_expect.m4 | |
Squashed 'third_party/glog/' content from commit 9ef754a3023
git-subtree-dir: third_party/glog git-subtree-split: 9ef754a3023e6fd10f20fe53dfca96dd898182e3
Diffstat (limited to 'm4/ac_have_builtin_expect.m4')
| -rw-r--r-- | m4/ac_have_builtin_expect.m4 | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/m4/ac_have_builtin_expect.m4 b/m4/ac_have_builtin_expect.m4 new file mode 100644 index 000000000000..e91b6fd987ed --- /dev/null +++ b/m4/ac_have_builtin_expect.m4 @@ -0,0 +1,14 @@ +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) +]) |