Re: [tree-ssa] Bootstrap broken on x86_64-linux-gnu

[Daniel Berlin <dberlin at dberlin dot org>]

> It does not apply but it does not look ok either, see below.
>
>
> > If not, it should be easy to see what i'm trying to do anyway (prevent
> > us from accessing a non existent array member).
> >
> >
> > Index: tree-ssa-pre.c
> > ===================================================================
> > RCS file: /cvs/gcc/gcc/gcc/Attic/tree-ssa-pre.c,v
> > retrieving revision 1.1.4.94
> > diff -u -3 -p -r1.1.4.94 tree-ssa-pre.c
> > --- tree-ssa-pre.c	24 Oct 2003 07:41:31 -0000	1.1.4.94
> > +++ tree-ssa-pre.c	29 Oct 2003 15:03:21 -0000
> > @@ -323,7 +323,8 @@ struct expr_info
> >
> >  /* Cache of expressions generated for given phi operand, to avoid
> >     recomputation and wasting memory.  */
> > -tree *phi_pred_cache;
> > +static tree *phi_pred_cache;
> > +static int n_phi_preds;
> >
> >  /* Trying to lookup ephi pred operand indexes takes forever on graphs
> >     that have high connectivity because it's an O(n) linked list
> > @@ -1193,7 +1224,6 @@
> >  /* Make a copy of Z as it would look in BB j, using the PHIs in BB.  
> > */
> >
> >  static tree
> >  subst_phis (struct expr_info *ei, tree Z, basic_block j, basic_block 
> > bb)
> >  {
> >    tree stmt_copy;
> > -  if (phi_pred_cache[j->index] != NULL_TREE)
>
> This line looks broken.  Do you really intend this?


It's replaced by the next few lines (which include a boundary check).

> > @@ -1200,6 +1232,12 @@
> > +
> > +  /* Return the cached version, if we have one. */
> > +  if (j->index < n_phi_preds
> > +      && phi_pred_cache[j->index] != NULL_TREE)
> >      return phi_pred_cache[j->index];
> > +
> > +  /* Otherwise, generate a new expression.  */
> >    pre_stats.exprs_generated++;
> >    stmt_copy = unshare_expr (Z);
> >    create_stmt_ann (stmt_copy);
> >    modify_stmt (stmt_copy);
> >    get_stmt_operands (stmt_copy);
> > @@ -1210,1 +1248,0 @@
> > -  phi_pred_cache[j->index] = stmt_copy;
> > @@ -1211,3 +1273,6 @@
> > +
> > +  if (j->index < n_phi_preds)
> > +    phi_pred_cache[j->index] = stmt_copy;
> >    return stmt_copy;
> >  }
> >
> > @@ -3045,6 +3129,7 @@ pre_expression (struct expr_info *slot,
> >    bitmap_clear (created_phi_preds);
> >    ephi_pindex_htab = htab_create (500, ephi_pindex_hash, 
> > ephi_pindex_eq, free);
> >    phi_pred_cache = xcalloc (last_basic_block, sizeof (tree));
> > +  n_phi_preds = last_basic_block;
> >
> >    if (!expr_phi_insertion ((bitmap *)data, ei))
> >      goto cleanup;
>
> Andreas
> --
>  Andreas Jaeger, aj@suse.de, http://www.suse.de/~aj
>   SuSE Linux AG, Deutschherrnstr. 15-19, 90429 Nürnberg, Germany
>    GPG fingerprint = 93A3 365E CE47 B889 DF7F  FED1 389A 563C C272 A126