re PR c++/36912 (ICE with "-frounding-math -g")

	PR c++/36912
	* varasm.c (initializer_constant_valid_p): A PLUS_EXPR
	or MINUS_EXPR of REAL_TYPE is not a valid constant initializer.
	(output_constant): Avoid crash after error.

From-SVN: r153936

gcc/ChangeLog

+2009-11-04  Jason Merrill  <jason@redhat.com>
+
+	PR c++/36912
+	* varasm.c (initializer_constant_valid_p): A PLUS_EXPR
+	or MINUS_EXPR of REAL_TYPE is not a valid constant initializer.
+	(output_constant): Avoid crash after error.
+
 2009-11-05  Martin Jambor  <mjambor@suse.cz>
 
 	* tree-sra.c (struct access): Changed comment of next_sibling field.

gcc/testsuite/ChangeLog

+2009-11-04  Jason Merrill  <jason@redhat.com>
+
+	PR c++/36912
+	* g++.dg/init/static-init2.C: New.
+
 2009-11-05  Janus Weil  <janus@gcc.gnu.org>
 
 	PR fortran/41556

gcc/testsuite/g++.dg/init/static-init2.C

+// PR c++/36912
+// { dg-options -frounding-math }
+const double c = .1, d = c+1;

gcc/varasm.c

@@ -4322,6 +4322,10 @@ initializer_constant_valid_p (tree value, tree endtype)
 
     case POINTER_PLUS_EXPR:
     case PLUS_EXPR:
+      /* Any valid floating-point constants will have been folded by now;
+	 with -frounding-math we hit this with addition of two constants.  */
+      if (TREE_CODE (endtype) == REAL_TYPE)
+	return NULL_TREE;
       if (! INTEGRAL_TYPE_P (endtype)
 	  || TYPE_PRECISION (endtype)
 	     >= int_or_pointer_precision (TREE_TYPE (value)))
@@ -4345,6 +4349,8 @@ initializer_constant_valid_p (tree value, tree endtype)
       break;
 
     case MINUS_EXPR:
+      if (TREE_CODE (endtype) == REAL_TYPE)
+	return NULL_TREE;
       if (! INTEGRAL_TYPE_P (endtype)
 	  || TYPE_PRECISION (endtype)
 	     >= int_or_pointer_precision (TREE_TYPE (value)))
@@ -4560,8 +4566,8 @@ output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
     case REAL_TYPE:
       if (TREE_CODE (exp) != REAL_CST)
 	error ("initializer for floating value is not a floating constant");
-
-      assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
+      else
+	assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
       break;
 
     case COMPLEX_TYPE: