The llvm.hexagon.M2.mpyd.rnd.hl.s0 intrinsic; known as __builtin_HEXAGON_M2_mpyd_rnd_hl_s0 in GCC.
See Implementation
The llvm.hexagon.M2.mpyd.rnd.hl.s0 intrinsic; known as __builtin_HEXAGON_M2_mpyd_rnd_hl_s0 in GCC.