[Bug target/119626] New: Use bfcvt arm instruction to cast to __bf16 when ARM target supports it

[mcccs at gmx dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119626

            Bug ID: 119626
           Summary: Use bfcvt arm instruction to cast to __bf16 when ARM
                    target supports it
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mcccs at gmx dot com
  Target Milestone: ---

__bf16 convert1(int a) {
    return (__bf16) a;
}

__bf16 convert2(float a) {
    return (__bf16) a;
}

compiled with -march=armv9-a+fp16 -Ofast

should make use of bfcvt instruction when available, it's slower otherwise