From c6a2bc2f87e14f81a979d8d648ce1a68a40e9833 Mon Sep 17 00:00:00 2001
From: Aldy Hernandez <aldyh@redhat.com>
Date: Fri, 13 Mar 2020 17:12:56 +0100
Subject: Fix infinite loop on truncating widest_irange copies.

---
 gcc/range-op.cc    |  6 +++++-
 gcc/value-range.cc | 15 ++++++---------
 2 files changed, 11 insertions(+), 10 deletions(-)

(limited to 'gcc')

diff --git a/gcc/range-op.cc b/gcc/range-op.cc
index ca87e8e..2e19a3c 100644
--- a/gcc/range-op.cc
+++ b/gcc/range-op.cc
@@ -3332,11 +3332,15 @@ widest_irange_tests ()
 static void
 multi_precision_range_tests ()
 {
-  // Test truncating copy.
+  // Test truncating copy to int_range<1>.
   int_range<3> big = build_range3 (10, 20, 30, 40, 50, 60);
   int_range<1> small = big;
   ASSERT_TRUE (small == int_range<1> (INT (10), INT (60)));
 
+  // Test truncating copy to int_range<2>.
+  int_range<2> medium = big;
+  ASSERT_TRUE (!medium.undefined_p ());
+
   // Test that a truncating copy of [MIN,20][22,40][80,MAX]
   // ends up as a conservative anti-range of ~[21,21].
   big = int_range<3> (vrp_val_min (integer_type_node), INT (20));
diff --git a/gcc/value-range.cc b/gcc/value-range.cc
index b996708..4a4c487 100644
--- a/gcc/value-range.cc
+++ b/gcc/value-range.cc
@@ -1798,12 +1798,7 @@ irange::intersect (const vrange &vr)
 void
 irange::multi_range_union (const irange &r)
 {
-  if (undefined_p ())
-    {
-      *this = r;
-      return;
-    }
-  else if (r.undefined_p ())
+  if (r.undefined_p ())
     return;
 
   // Do not worry about merging and such by reserving twice as many
@@ -1818,7 +1813,8 @@ irange::multi_range_union (const irange &r)
   // the merge is performed.
   //
   // [Xi,Yi]..[Xn,Yn]  U  [Xj,Yj]..[Xm,Ym]   -->  [Xk,Yk]..[Xp,Yp]
-  signop sign = TYPE_SIGN (type ());
+  tree ttype = r.type ();
+  signop sign = TYPE_SIGN (ttype);
   // ?? We may need something faster than vectors here, not sure.
   auto_vec<wide_int, 8> res;
   wide_int u1 ;
@@ -1858,7 +1854,7 @@ irange::multi_range_union (const irange &r)
 
   // Now normalize the vector removing any overlaps.
   i = 2;
-  int prec = TYPE_PRECISION (type ());
+  int prec = TYPE_PRECISION (ttype);
   wide_int max_val = wi::max_value (prec, sign);
   for (j = 2; j < k ; j += 2)
     {
@@ -1905,8 +1901,9 @@ irange::multi_range_union (const irange &r)
     }
 
   for (j = 0; j < i ; j++)
-    m_base[j] = wide_int_to_tree (type (), res [j]);
+    m_base[j] = wide_int_to_tree (ttype, res [j]);
   m_num_ranges = i / 2;
+  m_kind = VR_RANGE;
 
   if (flag_checking)
     check ();
-- 
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