This fixes missed placements of VUSEs during
gimplify_and_update_call_from_tree. The gimplifier doesn't fill
out virtual operands (it doesn't call update_stmt) - for a reason,
we'd mark it for renaming else. So we have to stick a VUSE on
every stmt that can possibly have one. update_stmt will remove
it again when it is not necessary.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard.
2011-10-10 Richard Guenther <rguent...@suse.de>
PR middle-end/50389
* gimple-fold.c (gimplify_and_update_call_from_tree): Do not
mark symbols for renaming. Append the VUSE to all statements
that possibly can have one.
* gcc.dg/torture/pr50389.c: New testcase.
Index: gcc/gimple-fold.c
===================================================================
*** gcc/gimple-fold.c (revision 179738)
--- gcc/gimple-fold.c (working copy)
*************** gimplify_and_update_call_from_tree (gimp
*** 588,600 ****
}
new_stmt = gsi_stmt (i);
if (gimple_in_ssa_p (cfun))
! {
! find_new_referenced_vars (new_stmt);
! mark_symbols_for_renaming (new_stmt);
! }
! /* If the new statement has a VUSE, update it with exact SSA name we
! know will reach this one. */
! if (gimple_vuse (new_stmt))
{
/* If we've also seen a previous store create a new VDEF for
the latter one, and make that the new reaching VUSE. */
--- 588,597 ----
}
new_stmt = gsi_stmt (i);
if (gimple_in_ssa_p (cfun))
! find_new_referenced_vars (new_stmt);
! /* If the new statement possibly has a VUSE, update it with exact SSA
! name we know will reach this one. */
! if (gimple_has_mem_ops (new_stmt))
{
/* If we've also seen a previous store create a new VDEF for
the latter one, and make that the new reaching VUSE. */
Index: gcc/testsuite/gcc.dg/torture/pr50389.c
===================================================================
*** gcc/testsuite/gcc.dg/torture/pr50389.c (revision 0)
--- gcc/testsuite/gcc.dg/torture/pr50389.c (revision 0)
***************
*** 0 ****
--- 1,15 ----
+ /* { dg-do compile } */
+ /* { dg-options "-freorder-blocks -ftracer" } */
+
+ extern int data[];
+ extern int i;
+
+ void
+ foo (void)
+ {
+ char buf[8];
+ __builtin___memcpy_chk (buf, data, i ? 8 : 4,
+ __builtin_object_size (buf, 0));
+ __builtin___memcpy_chk (buf, data, i ? 8 : 4,
+ __builtin_object_size (buf, 0));
+ }
