re PR tree-optimization/29680 (Misscompilation of spec2006 gcc)

PR tree-optimization/29680
	* tree-ssa-operands.c (access_can_touch_variable): Revert fix for
	PR 14784.

	* gcc.dg/alias-11.c: New test.


Co-Authored-By: Zdenek Dvorak <dvorakz@suse.cz>

From-SVN: r118754

gcc/ChangeLog

@@ -1,3 +1,10 @@
+2006-11-13  H.J. Lu  <hongjiu.lu@intel.com>
+	    Zdenek Dvorak <dvorakz@suse.cz>
+
+	PR tree-optimization/29680
+	* tree-ssa-operands.c (access_can_touch_variable): Revert fix for
+	PR 14784.
+
 2006-11-12  Jason Merrill  <jason@redhat.com>
 	    Andrew Pinski <pinskia@physics.uc.edu>
 

gcc/testsuite/ChangeLog

@@ -1,3 +1,9 @@
+2006-11-12  H.J. Lu  <hongjiu.lu@intel.com>
+	    Zdenek Dvorak <dvorakz@suse.cz>
+
+	PR tree-optimization/29680
+	* gcc.dg/alias-11.c: New test.
+
 2006-11-12  Roger Sayle  <roger@eyesopen.com>
 
 	PR rtl-optimization/29797

gcc/testsuite/gcc.dg/alias-11.c

@@ -0,0 +1,111 @@
+/* { dg-do run } */
+/* { dg-require-alias "" } */
+/* { dg-options "-O2" } */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct dw_cfi_struct
+{
+  struct dw_cfi_struct *dw_cfi_next;
+  const char *dw_cfi_addr;
+}
+dw_cfi_node;
+
+typedef struct dw_fde_struct
+{
+  const char *dw_fde_current_label;
+  dw_cfi_node *dw_fde_cfi;
+}
+dw_fde_node;
+
+dw_cfi_node *cie_cfi_head;
+unsigned fde_table_in_use;
+dw_fde_node *fde_table;
+
+__inline__ void
+add_cfi (dw_cfi_node **list_head, dw_cfi_node *cfi)
+{
+  dw_cfi_node **p;
+
+  for (p = list_head; (*p) != ((void *)0); p = &(*p)->dw_cfi_next)
+    ;
+
+  *p = cfi;
+}
+
+__inline__ struct dw_cfi_struct *
+new_cfi (void)
+{
+  dw_cfi_node *cfi = (dw_cfi_node *) malloc (sizeof (dw_cfi_node));
+
+  memset (cfi, 0, sizeof (dw_cfi_node));
+  return cfi;
+}
+
+char *
+dwarf2out_cfi_label (void)
+{
+  static char label[20];
+  static unsigned long label_num = 0;
+
+  sprintf (label, "*.%s%u", "LCFI", (unsigned) (label_num++));
+  return label;
+}
+
+void
+add_fde_cfi (const char *label, dw_cfi_node *cfi)
+{
+  if (label)
+    {
+      dw_fde_node *fde = fde_table + fde_table_in_use - 1;
+
+      if (*label == 0)
+	label = dwarf2out_cfi_label ();
+
+      if (fde->dw_fde_current_label == ((void *)0)
+	  || strcmp (label, fde->dw_fde_current_label))
+	{
+	  dw_cfi_node *xcfi;
+
+	  fde->dw_fde_current_label = label = strdup (label);
+
+	  xcfi = new_cfi ();
+	  xcfi->dw_cfi_addr = label;
+	  add_cfi (&fde->dw_fde_cfi, xcfi);
+	}
+
+      add_cfi (&fde->dw_fde_cfi, cfi);
+    }
+  else
+    add_cfi (&cie_cfi_head, cfi);
+}
+
+int
+main ()
+{
+  dw_cfi_node *cfi;
+  dw_fde_node *fde;
+
+  fde_table_in_use = 1;
+  fde_table = (dw_fde_node *) realloc (fde_table,
+				       sizeof (dw_fde_node));
+  memset (fde_table, 0, sizeof (dw_fde_node));
+  cfi = new_cfi ();
+  add_fde_cfi ("", cfi);
+
+  fde = &fde_table[0];
+  cfi = fde->dw_fde_cfi;
+
+  if (cfi == NULL)
+    abort ();
+
+  if (cfi->dw_cfi_addr == NULL)
+    abort ();
+
+  if (strcmp ("*.LCFI0", cfi->dw_cfi_addr))
+    abort ();
+
+  return 0;
+}

gcc/tree-ssa-operands.c

@@ -1151,11 +1151,16 @@ access_can_touch_variable (tree ref, tree alias, HOST_WIDE_INT offset,
 	   && flag_strict_aliasing
 	   && TREE_CODE (ref) != INDIRECT_REF
 	   && !MTAG_P (alias)
-	   && !var_ann (alias)->is_heapvar
 	   && (TREE_CODE (base) != INDIRECT_REF
 	       || TREE_CODE (TREE_TYPE (base)) != UNION_TYPE)
 	   && !AGGREGATE_TYPE_P (TREE_TYPE (alias))
 	   && TREE_CODE (TREE_TYPE (alias)) != COMPLEX_TYPE
+#if 0
+	   /* FIXME: PR tree-optimization/29680.  */
+	   && !var_ann (alias)->is_heapvar
+#else
+	   && !POINTER_TYPE_P (TREE_TYPE (alias))
+#endif
 	   /* When the struct has may_alias attached to it, we need not to
 	      return true.  */
 	   && get_alias_set (base))