[Bug target/106601] New: __builtin_bswap16 code gen could be improved with ZBB enabled

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106601

            Bug ID: 106601
           Summary: __builtin_bswap16 code gen could be improved with ZBB
                    enabled
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: target
          Assignee: pinskia at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---
            Target: riscv

unsigned short t(unsigned short a)
{
  return __builtin_bswap16(a);
}

This could just be rev8 followed by a srli (I think).