* tm.texi (NEED_MATH_LIBRARY): Document new target macro.

From-SVN: r20766

gcc/ChangeLog

 Sat Jun 27 22:37:05 1998  Jeffrey A Law  (law@cygnus.com)
 
+	* tm.texi (NEED_MATH_LIBRARY): Document new target macro.
+
 	* Makefile.in (gencheck): Remove $(TREE_H) dependency.
 
 Sat Jun 27 20:20:00 1998  John Carr  <jfc@mit.edu>

gcc/tm.texi

@@ -7457,4 +7457,13 @@ operations other than load, store and copy operations.
 You need only define this macro if the target holds values larger than
 @code{word_mode} in general purpose registers.  Most targets should not define
 this macro.
+
+@findex NEED_MATH_LIBRARY
+@item NEED_MATH_LIBRARY
+Define this macro as a C expression that is nonzero if @code{g++} should
+automatically link in the math library or to zero if @code{g++} should not
+automatically link in the math library.
+
+You need only define this macro if the target does not always need the math
+library linked into C++ programs.
 @end table