Fixing the cost model for large permuted SLP groups broke this due to
the excessive amount of garbage we create. A previous fix for this
was (ab-)using the cost-model so this one simply makes a hard upper
bound for SLP group sizes.
Bootstrap and regtest running on x86_64-unknown-linux-gnu.
Richard.
2016-12-09 Richard Biener <rguent...@suse.de>
PR tree-optimization/78699
* tree-vect-data-refs.c (vect_analyze_group_access_1): Limit
group size.
Index: gcc/tree-vect-data-refs.c
===================================================================
--- gcc/tree-vect-data-refs.c (revision 243474)
+++ gcc/tree-vect-data-refs.c (working copy)
@@ -2390,7 +2416,9 @@ vect_analyze_group_access_1 (struct data
if (groupsize == 0)
groupsize = count + gaps;
- if (groupsize > UINT_MAX)
+ /* This could be UINT_MAX but as we are generating code in a very
+ inefficient way we have to cap earlier. See PR78699 for example. */
+ if (groupsize > 4096)
{
if (dump_enabled_p ())
dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
