[PATCH, generic] New RTL primitive: `define_subst'

[Michael Zolotukhin]

>> Yeah, one or other way to being able to debug what exactly has been
>> performed during the iterator expansion is certainly desirable for the
>> future.
> We actually have internal machinery for dumping MDs with expanded
> iterators and substs, but this looks really kinda hack now.
> We're going to submit it as subsequent patch after that one
> is checked in (there'll be no change in `define_subst' interface) and some
> discussion about necessary infrastructure changes is performed.

It's fairly easy to dump MD-file with expanded iterators and subst -
we could do it in any gen*-utility with a small piece of code. Like
this:

+void
+print_rtl_list (struct queue_elem **q)
+{
+  struct queue_elem *elem;
+  for (elem = *q; elem ; elem = elem->next)
+    debug_rtx (elem->data);
+}
...
+      print_rtl_list (&define_attr_queue);
+      print_rtl_list (&define_pred_queue);
+      print_rtl_list (&define_insn_queue);
+      print_rtl_list (&define_cond_exec_queue);
+      print_rtl_list (&define_subst_queue);
+      print_rtl_list (&other_queue);

Currently I just  don't know what way should be used to invoke it - in
our development we use an environment variable as a trigger for this,
but this is a real hack:
+  if (getenv ("__DUMP_RTL_LIST"))
+    {
+      print_rtl_list (&define_attr_queue);
...
+    }

I don't believe this way is appropriate to be in the trunk - so, could
you please advise how it should be done? Maybe we should introduce a
new gen-utility which should be used only for dumping md-files and add
a new target into makefile to invoke it, or should we add a command
line option to existing utilities?

--
Thanks, Michael




-- 
---
Best regards,
Michael V. Zolotukhin,
Software Engineer
Intel Corporation.