[Bug target/103568] sub-optimal vector construction with two loaded doubles on Power10

2021-12-06 Thread segher at gcc dot gnu.org via Gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103568 Segher Boessenkool changed: What|Removed |Added Ever confirmed|0 |1 Status|UNCONFIRMED

[Bug target/103568] sub-optimal vector construction with two loaded doubles on Power10

2021-12-06 Thread segher at gcc dot gnu.org via Gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103568 --- Comment #1 from Segher Boessenkool --- Confirmed. This is cheaper in GPRs until we had the lxvrdx insn, which is power10 (ISA 3.1) itself. Wrt dword 1 being zeroed by fp insns. ISA 3.1 has a note saying this was true on all earlier implem