This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[PATCH] Fix PR46664


When aff_combination_add overflows MAX_AFF_ELTS it appends to ->rest
and for pointer typed combination does so in sizetype.  This shows
an inconsistency wrt aff_combination_to_tree which starts with ->rest,
adding to a non-pointer even for pointer typed combinations.

It seems more natural to add ->rest last and assume that the first
element of the combination will be the pointer base.  Starting with
->rest was probably done for efficiency reasons, not for code quality
or consistency with something else?

That way we won't end up creating a POINTER_PLUS_EXPR with bogus types
(looks like I was the one adding the pointer-plus-expr fixups to
tree-affine.c)

Bootstrap & regtest in progress on x86_64-unknown-linux-gnu.

Richard.

2010-11-26  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/46664
	* tree-affine.c (aff_combination_to_tree): Add rest last.

Index: gcc/tree-affine.c
===================================================================
*** gcc/tree-affine.c	(revision 167170)
--- gcc/tree-affine.c	(working copy)
*************** tree
*** 434,440 ****
  aff_combination_to_tree (aff_tree *comb)
  {
    tree type = comb->type;
!   tree expr = comb->rest;
    unsigned i;
    double_int off, sgn;
    tree type1 = type;
--- 434,440 ----
  aff_combination_to_tree (aff_tree *comb)
  {
    tree type = comb->type;
!   tree expr = NULL_TREE;
    unsigned i;
    double_int off, sgn;
    tree type1 = type;
*************** aff_combination_to_tree (aff_tree *comb)
*** 447,452 ****
--- 447,455 ----
      expr = add_elt_to_tree (expr, type, comb->elts[i].val, comb->elts[i].coef,
  			    comb);
  
+   if (comb->rest)
+     expr = add_elt_to_tree (expr, type, comb->rest, double_int_one, comb);
+ 
    /* Ensure that we get x - 1, not x + (-1) or x + 0xff..f if x is
       unsigned.  */
    if (double_int_negative_p (comb->offset))


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]