[COMMITTED] [prange] Do not assume all pointers are the same size [PR115009]

[Aldy Hernandez]

In a world with same sized pointers we can always reuse the storage
slots, but since this is not always the case, we need to be more
careful.  However, we can always store an undefined, because that
requires no extra storage.

gcc/ChangeLog:

        PR tree-optimization/115009
        * value-range-storage.cc (prange_storage::alloc): Do not assume
        all pointers are the same size.
        (prange_storage::prange_storage): Same.
        (prange_storage::fits_p): Same.
---
 gcc/value-range-storage.cc | 30 +++++++++++++++++++-----------
 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/gcc/value-range-storage.cc b/gcc/value-range-storage.cc
index bbae0da4772..8e8d61d5935 100644
--- a/gcc/value-range-storage.cc
+++ b/gcc/value-range-storage.cc
@@ -593,12 +593,12 @@ frange_storage::fits_p (const frange &) const
 prange_storage *
 prange_storage::alloc (vrange_internal_alloc &allocator, const prange &r)
 {
-  // Assume all pointers are the same size.
-  unsigned prec = TYPE_PRECISION (TREE_TYPE (null_pointer_node));
-  gcc_checking_assert (r.undefined_p () || TYPE_PRECISION (r.type ()) == prec);
-
-  typedef trailing_wide_ints<NINTS> twi;
-  size_t size = sizeof (prange_storage) + twi::extra_size (prec);
+  size_t size = sizeof (prange_storage);
+  if (!r.undefined_p ())
+    {
+      unsigned prec = TYPE_PRECISION (r.type ());
+      size += trailing_wide_ints<NINTS>::extra_size (prec);
+    }
   prange_storage *p = static_cast <prange_storage *> (allocator.alloc (size));
   new (p) prange_storage (r);
   return p;
@@ -610,8 +610,12 @@ prange_storage::prange_storage (const prange &r)
 {
   // It is the caller's responsibility to allocate enough space such
   // that the precision fits.
-  unsigned prec = TYPE_PRECISION (TREE_TYPE (null_pointer_node));
-  m_trailing_ints.set_precision (prec);
+  if (r.undefined_p ())
+    // Undefined ranges do not require any extra space for trailing
+    // wide ints.
+    m_trailing_ints.set_precision (0);
+  else
+    m_trailing_ints.set_precision (TYPE_PRECISION (r.type ()));
 
   set_prange (r);
 }
@@ -669,10 +673,14 @@ prange_storage::equal_p (const prange &r) const
 }
 
 bool
-prange_storage::fits_p (const prange &) const
+prange_storage::fits_p (const prange &r) const
 {
-  // All pointers are the same size.
-  return true;
+  // Undefined ranges always fit, because they don't store anything in
+  // the trailing wide ints.
+  if (r.undefined_p ())
+    return true;
+
+  return TYPE_PRECISION (r.type ()) <= m_trailing_ints.get_precision ();
 }
 
 
-- 
2.45.0