This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[PATCH] Fix hash checking ICE in temp slot handling (PR middle-end/91190)


Hi!

As mentioned in the PR, we ICE on the following testcase.
The problem is that offset_address (in this particular case) does
  update_temp_slot_address (XEXP (memref, 0), new_rtx);
  new_rtx = change_address_1 (memref, VOIDmode, new_rtx, 1, false);
where the first call inserts the address into a hash table and computes a
hash for it, but then change_address_1 will try to legitimize that address
and modifies it in place, so now the hash table contains an entry with an
incorrect hash value (and at incorrect spot in the hash table).
Next we end up trying to insert the legitimized address into the hash table
and the new hash table checking rightfully complains.

The following patch ensures later in-place modifications of the address
don't affect the hash table.  Bootstrapped/regtested on x86_64-linux and
i686-linux, ok for trunk?

2019-07-19  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/91190
	* function.c (insert_temp_slot_address): Store into the hash table
	a copy of address to avoid RTL sharing issues.

	* gcc.c-torture/compile/pr91190.c: New test.

--- gcc/function.c.jj	2019-07-10 15:52:56.785588326 +0200
+++ gcc/function.c	2019-07-18 09:40:40.172869182 +0200
@@ -704,7 +704,7 @@ static void
 insert_temp_slot_address (rtx address, class temp_slot *temp_slot)
 {
   struct temp_slot_address_entry *t = ggc_alloc<temp_slot_address_entry> ();
-  t->address = address;
+  t->address = copy_rtx (address);
   t->temp_slot = temp_slot;
   t->hash = temp_slot_address_compute_hash (t);
   *temp_slot_address_table->find_slot_with_hash (t, t->hash, INSERT) = t;
--- gcc/testsuite/gcc.c-torture/compile/pr91190.c.jj	2019-07-18 09:52:07.364298430 +0200
+++ gcc/testsuite/gcc.c-torture/compile/pr91190.c	2019-07-18 09:51:17.892058429 +0200
@@ -0,0 +1,31 @@
+/* PR middle-end/91190 */
+
+unsigned a[1], c;
+long d, h;
+int e[2], f, g;
+char i;
+
+int
+main ()
+{
+  char k = 0;
+  int l;
+  while (i || d)
+    {
+      if (g)
+	while (1)
+	  ;
+      e[1] = 0;
+      long m[2], n = ~(3 & (5 | (h | 9) * 2237420170));
+      g = 90 * n;
+      char b = m[300000000], j = 0;
+      c = 5 ^ a[c ^ (b & 5)];
+      int o = d;
+      k = o ? : j;
+      if (k)
+	for (l = 0; l < 3; l++)
+	  if (m[200000000000000000]) 
+	    __builtin_printf ("%d", f);
+    }
+  return 0; 
+}

	Jakub


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]