count-leading-zeros: new module

[gnulib.git] / m4 / count-leading-zeros.m4

diff --git a/m4/count-leading-zeros.m4 b/m4/count-leading-zeros.m4
new file mode 100644 (file)
index 0000000..1efb941
--- /dev/null
+++ b/m4/count-leading-zeros.m4
@@ -0,0 +1,15 @@
+# count-leading-zeros.m4 serial 1
+dnl Copyright (C) 2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_COUNT_LEADING_ZEROS],
+[
+  dnl We don't need (and can't compile) count_leading_zeros_ll
+  dnl unless the type 'unsigned long long int' exists.
+  AC_REQUIRE([AC_TYPE_UNSIGNED_LONG_LONG_INT])
+
+  dnl Prerequisites of lib/count-leading-zeros.h.
+  AC_REQUIRE([AC_C_INLINE])
+])