X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fhypotf.m4;h=b4ebe9e2349f4d33f54728ff1cfd32c05d00e82b;hb=6b168421262adda71eed4cca137c34c1a9d6b981;hp=c6185a543939bfa5c6fc4131e4269b4b4580f85b;hpb=b3f31eeaa29521c15f6d5523a50c3061faf4384b;p=gnulib.git

diff --git a/m4/hypotf.m4 b/m4/hypotf.m4
index c6185a543..b4ebe9e23 100644
--- a/m4/hypotf.m4
+++ b/m4/hypotf.m4
@@ -1,4 +1,4 @@
-# hypotf.m4 serial 2
+# hypotf.m4 serial 3
 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,
@@ -10,6 +10,9 @@ AC_DEFUN([gl_FUNC_HYPOTF],
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
   AC_REQUIRE([gl_FUNC_HYPOT])
 
+  dnl Persuade glibc <math.h> to declare hypotf().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   dnl Test whether hypotf() exists. Assume that hypotf(), if it exists, is
   dnl defined in the same library as hypot().
   save_LIBS="$LIBS"