simplify_using_ranges::two_valued_val_range_p has odd code to
verify that an anti-range is two-valued which relies on
num_pairs () returning two for anti-ranges despite there's only
one pair and relying on lower/upper_bound treating that argument
specially. I cannot convince myself that's even correct.
The following avoids this by using a temporary int_range<2> to
allow anti-ranges to be represented as union of two ranges.
* vr-values.cc (simplify_using_ranges::two_valued_val_range_p):
Canonicalize legacy range to int_range<2> before checking
for two valued-ness.
---
gcc/vr-values.cc | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/gcc/vr-values.cc b/gcc/vr-values.cc
index 365f4976a39..c188fff1f8c 100644
--- a/gcc/vr-values.cc
+++ b/gcc/vr-values.cc
@@ -2189,11 +2189,12 @@ bool
simplify_using_ranges::two_valued_val_range_p (tree var, tree *a, tree *b,
gimple *s)
{
- value_range vr = *query->get_value_range (var, s);
- vr.normalize_symbolics ();
- if (vr.varying_p () || vr.undefined_p ())
+ value_range r = *query->get_value_range (var, s);
+ r.normalize_symbolics ();
+ if (r.varying_p () || r.undefined_p ())
return false;
+ int_range<2> vr (r);
if ((vr.num_pairs () == 1 && vr.upper_bound () - vr.lower_bound () == 1)
|| (vr.num_pairs () == 2
&& vr.lower_bound (0) == vr.upper_bound (0)
--
2.35.3
