The following fixes PR71039 - we were failing to verify we can
insert the lhs on the predecessor edges.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard.
2016-05-10 Richard Biener <rguent...@suse.de>
PR tree-optimization/71039
* tree-ssa-phiprop.c: Include tree-ssa-loop.h.
(chk_uses): New function.
(propagate_with_phi): Verify we can safely replicate the lhs of an
aggregate assignment on all incoming edges.
* gcc.dg/torture/pr71039.c: New testcase.
Index: gcc/tree-ssa-phiprop.c
===================================================================
*** gcc/tree-ssa-phiprop.c (revision 236066)
--- gcc/tree-ssa-phiprop.c (working copy)
*************** along with GCC; see the file COPYING3.
*** 32,37 ****
--- 32,38 ----
#include "gimplify.h"
#include "gimple-iterator.h"
#include "stor-layout.h"
+ #include "tree-ssa-loop.h"
/* This pass propagates indirect loads through the PHI node for its
address to make the load source possibly non-addressable and to
*************** phiprop_insert_phi (basic_block bb, gphi
*** 230,235 ****
--- 231,249 ----
return res;
}
+ /* Verify if *idx is available at *DATA. */
+
+ static bool
+ chk_uses (tree t, tree *idx, void *data)
+ {
+ basic_block dom = (basic_block) data;
+ if (TREE_CODE (*idx) == SSA_NAME)
+ return (SSA_NAME_IS_DEFAULT_DEF (*idx)
+ || ! dominated_by_p (CDI_DOMINATORS,
+ gimple_bb (SSA_NAME_DEF_STMT (*idx)), dom));
+ return true;
+ }
+
/* Propagate between the phi node arguments of PHI in BB and phi result
users. For now this matches
# p_2 = PHI <&x, &y>
*************** propagate_with_phi (basic_block bb, gphi
*** 342,347 ****
--- 356,368 ----
insert aggregate copies on the edges instead. */
if (!is_gimple_reg_type (TREE_TYPE (TREE_TYPE (ptr))))
{
+ /* As we replicate the lhs on each incoming edge all
+ used SSA names have to be available there. */
+ if (! for_each_index (gimple_assign_lhs_ptr (use_stmt),
+ chk_uses,
+ get_immediate_dominator (CDI_DOMINATORS,
+ gimple_bb (phi))))
+ goto next;
phiprop_insert_phi (bb, phi, use_stmt, phivn, n);
/* Remove old stmt. The phi is taken care of by DCE. */
Index: gcc/testsuite/gcc.dg/torture/pr71039.c
===================================================================
*** gcc/testsuite/gcc.dg/torture/pr71039.c (revision 0)
--- gcc/testsuite/gcc.dg/torture/pr71039.c (working copy)
***************
*** 0 ****
--- 1,14 ----
+ /* { dg-do compile } */
+
+ struct wv
+ {
+ int qi;
+ } qp, *ft;
+ void *pb;
+
+ void
+ wz (void)
+ {
+ struct wv *vf = pb ? (struct wv *)&pb : &qp;
+ *ft = *vf;
+ }
