[PATCH] Add debugging helpers for ranger.

Aldy Hernandez aldyh@redhat.com
Tue Jun 15 11:47:41 GMT 2021


These are aids to help in debugging ranger based passes.

I find the ability to dump the current ranger knowledge for the
function being debugged invaluable during development.  Similarly for
subsets of the CFG.

Tested with a bootstrap and regtest, as well as countless sessions in
gdb :).

OK?

gcc/ChangeLog:

	* gimple-range.cc (debug_seed_ranger): New.
	(dump_ranger): New.
	(debug_ranger): New.
---
 gcc/gimple-range.cc | 71 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)

diff --git a/gcc/gimple-range.cc b/gcc/gimple-range.cc
index b534b8e0a2c..2a0da417708 100644
--- a/gcc/gimple-range.cc
+++ b/gcc/gimple-range.cc
@@ -1661,4 +1661,75 @@ disable_ranger (struct function *fun)
   fun->x_range_query = &global_ranges;
 }
 
+// =========================================
+// Debugging helpers.
+// =========================================
+
+// Query all statements in the IL to precalculate computable ranges in RANGER.
+
+static DEBUG_FUNCTION void
+debug_seed_ranger (gimple_ranger &ranger)
+{
+  // Recalculate SCEV to make sure the dump lists everything.
+  if (scev_initialized_p ())
+    {
+      scev_finalize ();
+      scev_initialize ();
+    }
+
+  basic_block bb;
+  int_range_max r;
+  FOR_EACH_BB_FN (bb, cfun)
+    {
+      gimple *last = last_stmt (bb);
+      if (last && gimple_get_lhs (last))
+	ranger.range_of_stmt (r, last);
+    }
+}
+
+// Dump all that ranger knows for the current function.
+
+DEBUG_FUNCTION void
+dump_ranger (FILE *out)
+{
+  gimple_ranger ranger;
+  debug_seed_ranger (ranger);
+  ranger.dump (out);
+}
+
+DEBUG_FUNCTION void
+debug_ranger ()
+{
+  dump_ranger (stderr);
+}
+
+// Dump all that ranger knows on a path of BBs.
+
+DEBUG_FUNCTION void
+dump_ranger (FILE *dump_file, const vec<basic_block> &path)
+{
+  if (path.length () == 0)
+    {
+      fprintf (dump_file, "empty\n");
+      return;
+    }
+
+  gimple_ranger ranger;
+  debug_seed_ranger (ranger);
+
+  unsigned i = path.length ();
+  do
+    {
+      i--;
+      ranger.dump_bb (dump_file, path[i]);
+    }
+  while (i > 0);
+}
+
+DEBUG_FUNCTION void
+debug_ranger (const vec<basic_block> &path)
+{
+  dump_ranger (stderr, path);
+}
+
 #include "gimple-range-tests.cc"
-- 
2.31.1



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