New module 'expm1f'.

[gnulib.git] / m4 / expm1f.m4

diff --git a/m4/expm1f.m4 b/m4/expm1f.m4
new file mode 100644 (file)
index 0000000..f78262a
--- /dev/null
+++ b/m4/expm1f.m4
@@ -0,0 +1,29 @@
+# expm1f.m4 serial 1
+dnl Copyright (C) 2011-2012 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_FUNC_EXPM1F],
+[
+  AC_REQUIRE([gl_MATH_H_DEFAULTS])
+  AC_REQUIRE([gl_FUNC_EXPM1])
+
+  dnl Persuade glibc <math.h> to declare expm1f().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
+  dnl Test whether expm1f() exists. Assume that expm1f(), if it exists, is
+  dnl defined in the same library as expm1().
+  save_LIBS="$LIBS"
+  LIBS="$LIBS $EXPM1_LIBM"
+  AC_CHECK_FUNCS([expm1f])
+  LIBS="$save_LIBS"
+  if test $ac_cv_func_expm1f = yes; then
+    EXPM1F_LIBM="$EXPM1_LIBM"
+  else
+    HAVE_EXPM1F=0
+    dnl Find libraries needed to link lib/expm1f.c.
+    EXPM1F_LIBM="$EXPM1_LIBM"
+  fi
+  AC_SUBST([EXPM1F_LIBM])
+])