https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65369
--- Comment #28 from Alan Modra <amodra at gmail dot com> --- Created attachment 35024 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35024&action=edit modified testcase without bswap optimization This modified testcase avoids triggering the bswap optimization but still shows a failure at -O3. So definitely not a problem caused by Thomas' patch. -O3 -fno-tree-slp-vectorize is OK -O3 slp dump shows weird offset of +12 between vector loads rather than +16 as is usual