re PR middle-end/46674 (Weak alias is mistakenly optimized away)

PR middle-end/46674
	PR middle-end/46221
	* varasm.c (symbol_alias_set_t): New typedef for derived pointer_set
	wrapper class.
	(symbol_alias_set_create): New wrapper function.
	(symbol_alias_set_destroy): Likewise.
	(symbol_alias_set_contains): Likewise.
	(symbol_alias_set_insert): Likewise.
	(compute_visible_aliases): Use the above and return symbol_alias_set_t,
	not a pointer_set.
	(remove_unreachable_alias_pairs): Adjust likewise to match.
	(finish_aliases_1): Likewise.

From-SVN: r168047

gcc/ChangeLog

@@ -1,3 +1,18 @@
+2010-12-19  Dave Korn  <dave.korn.cygwin@gmail.com>
+
+	PR middle-end/46674
+	PR middle-end/46221
+	* varasm.c (symbol_alias_set_t): New typedef for derived pointer_set
+	wrapper class.
+	(symbol_alias_set_create): New wrapper function.
+	(symbol_alias_set_destroy): Likewise.
+	(symbol_alias_set_contains): Likewise.
+	(symbol_alias_set_insert): Likewise.
+	(compute_visible_aliases): Use the above and return symbol_alias_set_t,
+	not a pointer_set.
+	(remove_unreachable_alias_pairs): Adjust likewise to match.
+	(finish_aliases_1): Likewise.
+
 2010-12-19  Chung-Lin Tang  <cltang@codesourcery.com>
 
 	* config/arm/arm.c (arm_legitimate_index_p): Add VFP load/store

gcc/varasm.c

@@ -5504,21 +5504,67 @@ do_assemble_alias (tree decl, tree target)
 #endif
 }
 
+/* Derived type for use by compute_visible_aliases and callers.  A symbol
+   alias set is a pointer set into which we enter IDENTIFIER_NODES bearing
+   the canonicalised assembler-level symbol names corresponding to decls
+   and their aliases.  */
+
+typedef struct pointer_set_t symbol_alias_set_t;
+
+/* Allocate and construct a symbol alias set.  */
+
+static symbol_alias_set_t *
+symbol_alias_set_create (void)
+{
+  return pointer_set_create ();
+}
+
+/* Destruct and free a symbol alias set.  */
+
+static void
+symbol_alias_set_destroy (symbol_alias_set_t *aset)
+{
+  pointer_set_destroy (aset);
+}
+
+/* Test if a symbol alias set contains a given name.  */
+
+static int
+symbol_alias_set_contains (const symbol_alias_set_t *aset, tree t)
+{
+  /* We accept either a DECL or an IDENTIFIER directly.  */
+  if (TREE_CODE (t) != IDENTIFIER_NODE)
+    t = DECL_ASSEMBLER_NAME (t);
+  t = targetm.asm_out.mangle_assembler_name (IDENTIFIER_POINTER (t));
+  return pointer_set_contains (aset, t);
+}
+
+/* Enter a new name into a symbol alias set.  */
+
+static int
+symbol_alias_set_insert (symbol_alias_set_t *aset, tree t)
+{
+  /* We accept either a DECL or an IDENTIFIER directly.  */
+  if (TREE_CODE (t) != IDENTIFIER_NODE)
+    t = DECL_ASSEMBLER_NAME (t);
+  t = targetm.asm_out.mangle_assembler_name (IDENTIFIER_POINTER (t));
+  return pointer_set_insert (aset, t);
+}
 
 /* Compute the set of indentifier nodes that is generated by aliases
    whose targets are reachable.  */
 
-static struct pointer_set_t *
+static symbol_alias_set_t *
 compute_visible_aliases (void)
 {
-  struct pointer_set_t *visible;
+  symbol_alias_set_t *visible;
   unsigned i;
   alias_pair *p;
   bool changed;
 
   /* We have to compute the set of visible nodes including aliases
      themselves.  */
-  visible = pointer_set_create ();
+  visible = symbol_alias_set_create ();
   do
     {
       changed = false;
@@ -5526,21 +5572,13 @@ compute_visible_aliases (void)
 	{
 	  struct cgraph_node *fnode = NULL;
 	  struct varpool_node *vnode = NULL;
-	  tree asmname = DECL_ASSEMBLER_NAME (p->decl);
-	  const char *str = IDENTIFIER_POINTER (asmname);
-
-	  if (str[0] == '*')
-	    {
-	      str ++;
-	      asmname = get_identifier (str);
-	    }
 
 	  fnode = cgraph_node_for_asm (p->target);
 	  vnode = (fnode == NULL) ? varpool_node_for_asm (p->target) : NULL;
 	  if ((fnode
 	       || vnode
-	       || pointer_set_contains (visible, p->target))
+	       || symbol_alias_set_contains (visible, p->target))
-	      && !pointer_set_insert (visible, asmname))
+	      && !symbol_alias_set_insert (visible, p->decl))
 	    changed = true;
 	}
     }
@@ -5555,7 +5593,7 @@ compute_visible_aliases (void)
 void
 remove_unreachable_alias_pairs (void)
 {
-  struct pointer_set_t *visible;
+  symbol_alias_set_t *visible;
   unsigned i;
   alias_pair *p;
 
@@ -5576,7 +5614,7 @@ remove_unreachable_alias_pairs (void)
 	  vnode = (fnode == NULL) ? varpool_node_for_asm (p->target) : NULL;
 	  if (!fnode
 	      && !vnode
-	      && !pointer_set_contains (visible, p->target))
+	      && !symbol_alias_set_contains (visible, p->target))
 	    {
 	      VEC_unordered_remove (alias_pair, alias_pairs, i);
 	      continue;
@@ -5586,7 +5624,7 @@ remove_unreachable_alias_pairs (void)
       i++;
     }
 
-  pointer_set_destroy (visible);
+  symbol_alias_set_destroy (visible);
 }
 
 
@@ -5596,7 +5634,7 @@ remove_unreachable_alias_pairs (void)
 void
 finish_aliases_1 (void)
 {
-  struct pointer_set_t *visible;
+  symbol_alias_set_t *visible;
   unsigned i;
   alias_pair *p;
 
@@ -5614,7 +5652,7 @@ finish_aliases_1 (void)
       target_decl = find_decl_and_mark_needed (p->decl, p->target);
       if (target_decl == NULL)
 	{
-	  if (pointer_set_contains (visible, p->target))
+	  if (symbol_alias_set_contains (visible, p->target))
 	    continue;
 
 	  if (! (p->emitted_diags & ALIAS_DIAG_TO_UNDEF)
@@ -5640,7 +5678,7 @@ finish_aliases_1 (void)
 	}
     }
 
-  pointer_set_destroy (visible);
+  symbol_alias_set_destroy (visible);
 }
 
 /* Second pass of completing pending aliases.  Emit the actual assembly.