postorder         752 src/cmd/5c/reg.c postorder(Reg *r, Reg **rpo2r, int32 n)
postorder         915 src/cmd/6c/reg.c postorder(Reg *r, Reg **rpo2r, int32 n)
postorder         853 src/cmd/8c/reg.c postorder(Reg *r, Reg **rpo2r, int32 n)
postorder         322 src/cmd/gc/popt.c postorder(Flow *r, Flow **rpo2r, int32 n)