half_powr: Implement using powr

v2: Use full precision implementation

Reviewer: Jeroen Ketema <j.ketema@xs4all.nl>
Signed-off-by: Jan Vesely <jan.vesely@rutgers.edu>
llvm-svn: 323942
GitOrigin-RevId: 3b8b4eb64da8979a306a549ec09b88dfd20c0c0b
4 files changed