https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81593
Bug ID: 81593 Summary: Optimize PowerPC vector set from vector extract Product: gcc Version: 8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: meissner at gcc dot gnu.org Target Milestone: --- Created attachment 41851 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41851&action=edit File to show the problem. If we doing a vector set for 64-bit DF/DI mode values on PowerPC VSX system, and one or both of the values used in the set came from a vector extract, we can optimize things to do only one XXPERMDI instead of doing 3 XXPERMDI's (2 to isolate each element, and a third to recombine them back together again).