b38aa29717
This builtin will be converted to llvm.set.rounding intrinsic in IR level and should be work with "#pragma STDC FENV_ACCESS ON" since it changes default FP environment. Users can change rounding mode via this builtin without introducing libc dependency. Reviewed by: andrew.w.kaylor, rjmccall, sepavloff, aaron.ballman Differential Revision: https://reviews.llvm.org/D145765 Signed-off-by: jinge90 <ge.jin@intel.com>