usr/src/cmd/pcc/mac2defs

/*      PDP11 Registers */

        /* scratch registers */
# define R0 0
# define R1 1

        /* register variables */
# define R2 2
# define R3 3
# define R4 4

        /* special purpose */
# define R5 5   /* frame pointer */
# define SP 6   /* stack pointer */
# define PC 7   /* program counter */

        /* floating registers */

# define FR0 8
# define FR1 9
# define FR2 10
# define FR3 11
# define FR4 12
# define FR5 13

# define SAVEREGION 8 /* number of bytes for save area */

# define BYTEOFF(x) ((x)&01)
# define wdal(k) (BYTEOFF(k)==0)
# define BITOOR(x) ((x)>>3)  /* bit offset to oreg offset */

# define REGSZ 14

# define TMPREG R5


# define STOARG(p)     /* just evaluate the arguments, and be done with it... */
# define STOFARG(p)
# define STOSTARG(p)
# define genfcall(a,b) gencall(a,b)


        /* shape for constants between -128 and 127 */
# define SCCON (SPECIAL+100)
        /* shape for constants between 0 and 32767 */
# define SICON (SPECIAL+101)

# define MYREADER(p) myreader(p)
extern int fltused;
        /* calls can be nested on the PDP-11 */
# define NESTCALLS