Don't create SSA names until in SSA form

An upcoming patch adds a fold from hypot(x,x) to fabs(x)*sqrt(2).
This is unusual in that it could trigger in the gimplifier but would
require new SSA names to be created.  This patch makes sure that we
use the usual:

	  if (gimple_in_ssa_p (cfun))
	    res = make_ssa_name (type);
	  else
	    res = create_tmp_reg (type);

formula to cope with cases where we're not yet in SSA form.

Tested on x86_64-linux-gnu, aarch64-linux-gnu and arm-linux-gnueabi.

gcc/
	* gimple-match-head.c (maybe_push_res_to_seq): Use create_tmp_reg
	instead of make_ssa_name if not yet in SSA form.

From-SVN: r229406

gcc/ChangeLog

+2015-10-27  Richard Sandiford  <richard.sandiford@arm.com>
+
+	* gimple-match-head.c (maybe_push_res_to_seq): Use create_tmp_reg
+	instead of make_ssa_name if not yet in SSA form.
+
 2015-10-27  Richard Biener  <rguenther@suse.de>
 
 	* cfg.c (free_edge): Add function argument and use it instead of cfun.

gcc/gimple-match-head.c

@@ -331,7 +331,12 @@ maybe_push_res_to_seq (code_helper rcode, tree type, tree *ops,
 	      && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ops[2])))
 	return NULL_TREE;
       if (!res)
-	res = make_ssa_name (type);
+	{
+	  if (gimple_in_ssa_p (cfun))
+	    res = make_ssa_name (type);
+	  else
+	    res = create_tmp_reg (type);
+	}
       maybe_build_generic_op (rcode, type, &ops[0], ops[1], ops[2]);
       gimple *new_stmt = gimple_build_assign (res, rcode,
 					     ops[0], ops[1], ops[2]);
@@ -361,7 +366,12 @@ maybe_push_res_to_seq (code_helper rcode, tree type, tree *ops,
 	}
       gcc_assert (nargs != 0);
       if (!res)
-	res = make_ssa_name (type);
+	{
+	  if (gimple_in_ssa_p (cfun))
+	    res = make_ssa_name (type);
+	  else
+	    res = create_tmp_reg (type);
+	}
       gimple *new_stmt = gimple_build_call (decl, nargs, ops[0], ops[1], ops[2]);
       gimple_call_set_lhs (new_stmt, res);
       gimple_seq_add_stmt_without_update (seq, new_stmt);