re PR tree-optimization/41775 (IPA-SRA: ice in rewrite_stmt, at tree-into-ssa.c:1302)

2009-10-29  Martin Jambor  <mjambor@suse.cz>

	PR tree-optimization/41775
	* tree-sra.c (build_ref_for_offset): Unshare *expr if not NULL.
	(generate_subtree_copies): Do not unshare agg.
	(load_assign_lhs_subreplacements): Do not unshare rhs.
	(sra_modify_assign): Do not unshare exprs.
	(propagate_subacesses_accross_link): Renamed to
	propagate_subaccesses_across_link.

	* testsuite/g++.dg/torture/pr41775.C: New testcase.

From-SVN: r153699

1 files changed, 13 insertions, 9 deletions

diff --git a/gcc/tree-sra.c b/gcc/tree-sra.c
index 8624668..a86a441 100644
--- a/gcc/tree-sra.c
+++ b/gcc/tree-sra.c
@@ -1304,7 +1304,8 @@ build_ref_for_offset_1 (tree *res, tree type, HOST_WIDE_INT offset,
 /* Construct an expression that would reference a part of aggregate *EXPR of
    type TYPE at the given OFFSET of the type EXP_TYPE.  If EXPR is NULL, the
    function only determines whether it can build such a reference without
-   actually doing it.
+   actually doing it, otherwise, the tree it points to is unshared first and
+   then used as a base for furhter sub-references.
 
    FIXME: Eventually this should be replaced with
    maybe_fold_offset_to_reference() from tree-ssa-ccp.c but that requires a
@@ -1317,6 +1318,9 @@ build_ref_for_offset (tree *expr, tree type, HOST_WIDE_INT offset,
 {
   location_t loc = expr ? EXPR_LOCATION (*expr) : UNKNOWN_LOCATION;
 
+  if (expr)
+    *expr = unshare_expr (*expr);
+
   if (allow_ptr && POINTER_TYPE_P (type))
     {
       type = TREE_TYPE (type);
@@ -1759,7 +1763,7 @@ create_artificial_child_access (struct access *parent, struct access *model,
    access but LACC is not, change the type of the latter, if possible.  */
 
 static bool
-propagate_subacesses_accross_link (struct access *lacc, struct access *racc)
+propagate_subaccesses_across_link (struct access *lacc, struct access *racc)
 {
   struct access *rchild;
   HOST_WIDE_INT norm_delta = lacc->offset - racc->offset;
@@ -1800,7 +1804,7 @@ propagate_subacesses_accross_link (struct access *lacc, struct access *racc)
 	      rchild->grp_hint = 1;
 	      new_acc->grp_hint |= new_acc->grp_read;
 	      if (rchild->first_child)
-		ret |= propagate_subacesses_accross_link (new_acc, rchild);
+		ret |= propagate_subaccesses_across_link (new_acc, rchild);
 	    }
 	  continue;
 	}
@@ -1818,7 +1822,7 @@ propagate_subacesses_accross_link (struct access *lacc, struct access *racc)
 	{
 	  ret = true;
 	  if (racc->first_child)
-	    propagate_subacesses_accross_link (new_acc, rchild);
+	    propagate_subaccesses_across_link (new_acc, rchild);
 	}
     }
 
@@ -1844,7 +1848,7 @@ propagate_all_subaccesses (void)
 	  if (!bitmap_bit_p (candidate_bitmap, DECL_UID (lacc->base)))
 	    continue;
 	  lacc = lacc->group_representative;
-	  if (propagate_subacesses_accross_link (lacc, racc)
+	  if (propagate_subaccesses_across_link (lacc, racc)
 	      && lacc->first_link)
 	    add_access_to_work_queue (lacc);
 	}
@@ -1960,7 +1964,7 @@ generate_subtree_copies (struct access *access, tree agg,
 {
   do
     {
-      tree expr = unshare_expr (agg);
+      tree expr = agg;
 
       if (chunk_size && access->offset >= start_offset + chunk_size)
 	return;
@@ -2235,7 +2239,7 @@ load_assign_lhs_subreplacements (struct access *lacc, struct access *top_racc,
 		rhs = unshare_expr (lacc->expr);
 	      else
 		{
-		  rhs = unshare_expr (top_racc->base);
+		  rhs = top_racc->base;
 		  repl_found = build_ref_for_offset (&rhs,
 						     TREE_TYPE (top_racc->base),
 						     offset, lacc->type, false);
@@ -2372,7 +2376,7 @@ sra_modify_assign (gimple *stmt, gimple_stmt_iterator *gsi,
 	  if (AGGREGATE_TYPE_P (TREE_TYPE (lhs))
 	      && !access_has_children_p (lacc))
 	    {
-	      tree expr = unshare_expr (lhs);
+	      tree expr = lhs;
 	      if (build_ref_for_offset (&expr, TREE_TYPE (lhs), 0,
 					TREE_TYPE (rhs), false))
 		{
@@ -2383,7 +2387,7 @@ sra_modify_assign (gimple *stmt, gimple_stmt_iterator *gsi,
 	  else if (AGGREGATE_TYPE_P (TREE_TYPE (rhs))
 		   && !access_has_children_p (racc))
 	    {
-	      tree expr = unshare_expr (rhs);
+	      tree expr = rhs;
 	      if (build_ref_for_offset (&expr, TREE_TYPE (rhs), 0,
 					TREE_TYPE (lhs), false))
 		rhs = expr;