sys/h/reg.h

/*      reg.h   4.2     81/02/19        */
/*
 * Location of the users' stored
 * registers relative to R0.
 * Usage is u.u_ar0[XX].
 */
#define R0      (-18)
#define R1      (-17)
#define R2      (-16)
#define R3      (-15)
#define R4      (-14)
#define R5      (-13)
#define R6      (-12)
#define R7      (-11)
#define R8      (-10)
#define R9      (-9)
#define R10     (-8)
#define R11     (-7)
#define R12     (-21)
#define R13     (-20)

#define AP      (-21)
#define FP      (-20)
#define SP      (-5)
#define PS      (-1)
#define PC      (-2)