Hi,
The previous solution for PR77916 was inadequately tested, for which I
sincerely apologize. I've reinstated the stopgap fix previously
reverted, as follows.
Thanks for your patience,
Bill
2016-10-18 Bill Schmidt <wschm...@linux.vnet.ibm.com>
PR tree-optimization/77916
* gimple-ssa-strength-reduction.c (analyze_increments): Reinstate
stopgap fix, as pointers with -1 increment are still broken.
Index: gcc/gimple-ssa-strength-reduction.c
===================================================================
--- gcc/gimple-ssa-strength-reduction.c (revision 241302)
+++ gcc/gimple-ssa-strength-reduction.c (working copy)
@@ -2825,6 +2825,10 @@ analyze_increments (slsr_cand_t first_dep, machine
&& !POINTER_TYPE_P (first_dep->cand_type)))
incr_vec[i].cost = COST_NEUTRAL;
+ /* FIXME: Still having trouble with pointers with a -1 increment. */
+ else if (incr == -1 && POINTER_TYPE_P (first_dep->cand_type))
+ incr_vec[i].cost = COST_INFINITE;
+
/* FORNOW: If we need to add an initializer, give up if a cast from
the candidate's type to its stride's type can lose precision.
This could eventually be handled better by expressly retaining the
