[Bug target/106708] New: [rs6000] 64bit constant generation with oris xoris

[guojiufu at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106708

            Bug ID: 106708
           Summary: [rs6000] 64bit constant generation with oris xoris
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: guojiufu at gcc dot gnu.org
  Target Milestone: ---

For code: t.c
void foo (long *arg)
{
  *arg++ = 0x98765432ULL;
  *arg++ = 0xffffffff7cdeab55ULL;
  *arg++ = 0xffffffff65430000ULL;
}

gcc -O2 -S t.c
        lis 10,0xffff
        lis 8,0x9876
        ori 10,10,0x7cde
        lis 9,0xffff
        ori 8,8,0x5432
        sldi 10,10,16
        ori 9,9,0x6543
        rldicl 8,8,0,32
        ori 10,10,0xab55
        sldi 9,9,16

Below sequences would be better:
        li 8,21554
        li 10,-21675
        lis 9,0xe543
        oris 8,8,0x9876
        xoris 10,10,0x8321
        xoris 9,9,0x8000