[PATCH] Allow copying of symbolic ranges to an irange.

[Aldy Hernandez]

 >>  // Swap min/max if they are out of order.  Return TRUE if further
 > these seems OK, but can't there be anti-ranges with symbolics  too? ie
 > ~[a_12, a_12]
 > The code for that just does:
 >
 >   else if (src.kind () == VR_ANTI_RANGE)
 >      set (src.min (), src.max (), VR_ANTI_RANGE);
 >
 > That should just go to varying I guess?

Ah, you're right.  I've tweaked the patch and have added a corresponding 
test.

 >
 > The conversion to legacy anti-range code also seems a little suspect in
 > some cases...
 >
 > Finally, we theoretically shouldn't be accessing 'min()' and 'max()'
 > fields in a multirange, which also looks like might happen in the final
 > else clause.
 >
 > I wonder if it might be less complex to simply have 2 routines, like
 > copy_to_legacy()  and copy_from_legacy()  instead of trying to handle
 > then together?  I do find it seems to require more thinking than it
 > should to follow the cases :-)

Sigh, yes.  That code is too clever for its own good.  I'll work on it 
as a follow-up.

OK pending tests?

Aldy

gcc/ChangeLog:

	* range-op.cc (multi_precision_range_tests): Normalize symbolics when 
copying to a multi-range.
	* value-range.cc (irange::copy_legacy_range): Add test.
---
  gcc/range-op.cc    | 15 +++++++++++++++
  gcc/value-range.cc | 19 +++++++++++++++++--
  2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/gcc/range-op.cc b/gcc/range-op.cc
index fbf78be0a3c..3ab268f101e 100644
--- a/gcc/range-op.cc
+++ b/gcc/range-op.cc
@@ -3453,6 +3453,21 @@ multi_precision_range_tests ()
    small = big;
    ASSERT_TRUE (small == int_range<1> (INT (21), INT (21), VR_ANTI_RANGE));

+  // Copying a legacy symbolic to an int_range should normalize the
+  // symbolic at copy time.
+  {
+    tree ssa = make_ssa_name (integer_type_node);
+    value_range legacy_range (ssa, INT (25));
+    int_range<2> copy = legacy_range;
+    ASSERT_TRUE (copy == int_range<2>  (vrp_val_min (integer_type_node),
+					INT (25)));
+
+    // Test that copying ~[abc_23, abc_23] to a multi-range yields varying.
+    legacy_range = value_range (ssa, ssa, VR_ANTI_RANGE);
+    copy = legacy_range;
+    ASSERT_TRUE (copy.varying_p ());
+  }
+
    range3_tests ();
  }

diff --git a/gcc/value-range.cc b/gcc/value-range.cc
index 20aa4f114c9..ed2c322ded9 100644
--- a/gcc/value-range.cc
+++ b/gcc/value-range.cc
@@ -92,7 +92,12 @@ irange::copy_legacy_range (const irange &src)
    else if (src.varying_p ())
      set_varying (src.type ());
    else if (src.kind () == VR_ANTI_RANGE)
-    set (src.min (), src.max (), VR_ANTI_RANGE);
+    {
+      if (src.legacy_mode_p () && !range_has_numeric_bounds_p (&src))
+	set_varying (src.type ());
+      else
+	set (src.min (), src.max (), VR_ANTI_RANGE);
+    }
    else if (legacy_mode_p () && src.maybe_anti_range ())
      {
        int_range<3> tmp (src);
@@ -101,7 +106,17 @@ irange::copy_legacy_range (const irange &src)
  	   VR_ANTI_RANGE);
      }
    else
-    set (src.min (), src.max (), VR_RANGE);
+    {
+      // If copying legacy to int_range, normalize any symbolics.
+      if (src.legacy_mode_p () && !range_has_numeric_bounds_p (&src))
+	{
+	  value_range cst (src);
+	  cst.normalize_symbolics ();
+	  set (cst.min (), cst.max ());
+	  return;
+	}
+      set (src.min (), src.max ());
+    }
  }

  // Swap min/max if they are out of order.  Return TRUE if further
-- 
2.26.2