Re: GCC 4.3.3 Release Candidate available from gcc.gnu.org

[Richard Guenther]

On Sun, 18 Jan 2009, H.J. Lu wrote:

> On Sat, Jan 17, 2009 at 6:23 AM, Richard Guenther <rguent...@suse.de> wrote:
> >
> > A release candidate for GCC 4.3.3 is available from
> >
> > ftp://gcc.gnu.org/pub/gcc/snapshots/4.3.3-RC-20090117/
> >
> > and shortly its mirrors.  It has been generated from SVN revision 143460.
> >
> > The branch is still frozen and all checkins until after the final
> > release of GCC 4.3.3 require explicit RM approval.
> >
> 
> Gcc 4.3.3 miscompiled SPEC CPU 2006 on Linux/x86-64:
> 
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38905

I am testing the following patch.

Richard.

2008-07-11  Richard Guenther  <rguent...@suse.de>

        PR tree-optimization/36765
        * tree-ssa-alias.c (compute_flow_insensitive_aliasing): Add
        aliases from HEAP vars to SMTs.

        * gcc.c-torture/execute/pr36765.c: New testcase.

Index: gcc/tree-ssa-alias.c
===================================================================
*** gcc/tree-ssa-alias.c        (revision 137712)
--- gcc/tree-ssa-alias.c        (working copy)
*************** have_common_aliases_p (bitmap tag1aliase
*** 2370,2375 ****
--- 2370,2377 ----
  static void
  compute_flow_insensitive_aliasing (struct alias_info *ai)
  {
+   referenced_var_iterator rvi;
+   tree var;
    size_t i;
  
    timevar_push (TV_FLOW_INSENSITIVE);
*************** compute_flow_insensitive_aliasing (struc
*** 2460,2465 ****
--- 2462,2485 ----
          add_may_alias (tag1, tag2);
        }
      }
+ 
+   /* We have to add all HEAP variables to all SMTs aliases bitmaps.
+      As we don't know which effective type the HEAP will have we cannot
+      do better here and we need the conflicts with obfuscated pointers
+      (a simple (*(int[n] *)ptr)[i] will do, with ptr from a VLA array
+      allocation).  */
+   for (i = 0; i < ai->num_pointers; i++)
+     {
+       struct alias_map_d *p_map = ai->pointers[i];
+       tree tag = symbol_mem_tag (p_map->var);
+ 
+       FOR_EACH_REFERENCED_VAR (var, rvi)
+       {
+         if (var_ann (var)->is_heapvar)
+           add_may_alias (tag, var);
+       }
+     }
+ 
    timevar_pop (TV_FLOW_INSENSITIVE);
  }
  
Index: gcc/testsuite/gcc.c-torture/execute/pr36765.c
===================================================================
*** gcc/testsuite/gcc.c-torture/execute/pr36765.c       (revision 0)
--- gcc/testsuite/gcc.c-torture/execute/pr36765.c       (revision 0)
***************
*** 0 ****
--- 1,15 ----
+ int __attribute__((noinline))
+ foo(int i)
+ {
+   int *p = __builtin_malloc (4 * sizeof(int));
+   *p = 0;
+   p[i] = 1;
+   return *p;
+ }
+ extern void abort (void);
+ int main()
+ {
+   if (foo(0) != 1)
+     abort ();
+   return 0;
+ }