Patch to optabs.c

["tim_ouyang"@sunplus.com.tw]

Hello,

The following patch fixes a bug in expand_binop(). When the operation is add or
sub, the original optabs.c forgets to copy the result of first word back to
target.

I am porting GCC to a 16-bit micro-processor. When I feed the testsuite into the
ported GCC, I found this bug. After add this patch, the GCC works fine and
generates correct codes.

==========8<==============8<============

[/gcc-snapshot/gcc]$ diff -Nau optabs.c optabs.c.new
--- optabs.c    Fri Nov 17 14:05:15 2000
+++ optabs.c.new        Tue Dec 26 15:08:05 2000
@@ -1230,6 +1230,13 @@
                    break;
                }
            }
+         else
+           {
+             if (x == 0)
+               break;
+             else if (target_piece != x)
+               emit_move_insn (target_piece, x);
+            }

          carry_in = carry_out;
        }

==========>8==============>8============

Happy New Year!

Tim Ouyang (¼Ú¶§¤h®x)
IP Design Dept.
Intellectual Property Development Division
Sunplus Technology Co.,Ltd.
19, Innovation Road 1, Science-Based Industrial Park, Hsin-Chu, Taiwan

Phone: +886-3-5786005 Ext. 2467
Fax: +886-3-5784418
E-Mail : tim_ouyang@sunplus.com.tw