Fix uninitialized access in merge_call_side_effects

gcc/ChangeLog:

	PR ipa/103262
	* ipa-modref.c (merge_call_side_effects): Fix uninitialized
	access.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/modref-dse-5.c: New test.

diff --git a/gcc/ipa-modref.c b/gcc/ipa-modref.c
index d9d48cc22915956d467766a79fc9df6e6f89da34..5783430329040288a8e73862d3baf208429a3df3 100644 (file)
--- a/gcc/ipa-modref.c
+++ b/gcc/ipa-modref.c
@@ -1014,38 +1014,6 @@ merge_call_side_effects (modref_summary *cur_summary,
       changed = true;
     }
 
-  if (always_executed
-      && callee_summary->kills.length ()
-      && (!cfun->can_throw_non_call_exceptions
-         || !stmt_could_throw_p (cfun, stmt)))
-    {
-      /* Watch for self recursive updates.  */
-      auto_vec<modref_access_node, 32> saved_kills;
-
-      saved_kills.reserve_exact (callee_summary->kills.length ());
-      saved_kills.splice (callee_summary->kills);
-      for (auto kill : saved_kills)
-       {
-         if (kill.parm_index >= (int)parm_map.length ())
-           continue;
-         modref_parm_map &m
-                 = kill.parm_index == MODREF_STATIC_CHAIN_PARM
-                   ? chain_map
-                   : parm_map[kill.parm_index];
-         if (m.parm_index == MODREF_LOCAL_MEMORY_PARM
-             || m.parm_index == MODREF_UNKNOWN_PARM
-             || m.parm_index == MODREF_RETSLOT_PARM
-             || !m.parm_offset_known)
-           continue;
-         modref_access_node n = kill;
-         n.parm_index = m.parm_index;
-         n.parm_offset += m.parm_offset;
-         if (modref_access_node::insert_kill (cur_summary->kills, n,
-                                              record_adjustments))
-           changed = true;
-       }
-    }
-
   /* We can not safely optimize based on summary of callee if it does
      not always bind to current def: it is possible that memory load
      was optimized out earlier which may not happen in the interposed
@@ -1095,6 +1063,38 @@ merge_call_side_effects (modref_summary *cur_summary,
   if (dump_file)
     fprintf (dump_file, "\n");
 
+  if (always_executed
+      && callee_summary->kills.length ()
+      && (!cfun->can_throw_non_call_exceptions
+         || !stmt_could_throw_p (cfun, stmt)))
+    {
+      /* Watch for self recursive updates.  */
+      auto_vec<modref_access_node, 32> saved_kills;
+
+      saved_kills.reserve_exact (callee_summary->kills.length ());
+      saved_kills.splice (callee_summary->kills);
+      for (auto kill : saved_kills)
+       {
+         if (kill.parm_index >= (int)parm_map.length ())
+           continue;
+         modref_parm_map &m
+                 = kill.parm_index == MODREF_STATIC_CHAIN_PARM
+                   ? chain_map
+                   : parm_map[kill.parm_index];
+         if (m.parm_index == MODREF_LOCAL_MEMORY_PARM
+             || m.parm_index == MODREF_UNKNOWN_PARM
+             || m.parm_index == MODREF_RETSLOT_PARM
+             || !m.parm_offset_known)
+           continue;
+         modref_access_node n = kill;
+         n.parm_index = m.parm_index;
+         n.parm_offset += m.parm_offset;
+         if (modref_access_node::insert_kill (cur_summary->kills, n,
+                                              record_adjustments))
+           changed = true;
+       }
+    }
+
   /* Merge with callee's summary.  */
   changed |= cur_summary->loads->merge (callee_summary->loads, &parm_map,
                                        &chain_map, record_adjustments);

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/modref-dse-5.c b/gcc/testsuite/gcc.dg/tree-ssa/modref-dse-5.c
new file mode 100644 (file)
index 0000000..ad35b70
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/modref-dse-5.c
@@ -0,0 +1,43 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-dse2-details"  } */
+struct a {int a,b,c;};
+__attribute__ ((noinline))
+void
+kill_me (struct a *a)
+{
+  a->a=0;
+  a->b=0;
+  a->c=0;
+}
+__attribute__ ((noinline))
+int
+wrap(int b, struct a *a)
+{
+   kill_me (a);
+   return b;
+}
+__attribute__ ((noinline))
+void
+my_pleasure (struct a *a)
+{
+  a->a=1;
+  a->c=2;
+}
+__attribute__ ((noinline))
+int
+wrap2(int b, struct a *a)
+{
+   my_pleasure (a);
+   return b;
+}
+
+int
+set (struct a *a)
+{
+  wrap (0, a);
+  int ret = wrap2 (0, a);
+  //int ret = my_pleasure (a);
+  a->b=1;
+  return ret;
+}
+/* { dg-final { scan-tree-dump "Deleted dead store: wrap" "dse2" } } */