CPS 104			 Problem P3








     _R_e_d_u_c_e_d _M_a_c_h_i_n_e _I_n_s_t_r_u_c_t_i_o_n _S_e_t (_R_M_I) _P_r_o_g_r_a_m_m_i_n_g

     The instruction set of the	RMI consists  of  just	five
operations, R, P, SUB, BLTZ, and XIT, defined as follows:

	#include <stdio.h>
	int ICT=0;
	#define	R(F,X) \
		scanf(F,&X); ICT++;

	#define	P(F,A) \
		printf(F,A); ICT++;

	#define	SUB(X,A,B) \
		X = (A=A) - B; ICT++;

	#define	BLTZ(A,S) \
		ICT++; if (A<0)	goto S;

	#define	XIT() \
		printf("%d RMI Instructions executed.\n", ICT);


     Here, F is	an appropriate format string, A	 and  X
     must  be  scalar  integer C variables, S must be a
     label, and	B may be either	an integer constant, or
     an	 integer  C  variable:	The format string F may
     contain no	conversion specifiers other than %c and
     %d,  but  feel free to use	any characters you want
     which are simply copied to	 the  output,  such  as
     "E", and "\n".

     Using ONLY	these statements (and  C  declarations,	 and
subroutine  definitions	 and  calls, but no other C commands
such as	"return" or "for", and no other	C operators or	com-
parisons), write a program which does the following:

     Reads a series of integers	from stdin,  until  one
     whose  value  is  0  is  encountered, and for each
     integer I except the final	0, prints one  line  of
     output:

	     I bbb...bbb Q j


     Here, I is	the original number, bbb...bbb	is  its
     binary representation, consisting of 32 1s	and 0s;
     Q is the letter E if I is even, and is the	 letter
     O	(capital  "o", not digit "0") if I is odd; j is
     the decimal representation	of the value  of  I>>5,
     where  I>>5  is  an  expression whose value is the
     result of shifting	I RIGHT	5 bit positions.   Each
     output  field  must be separated from any previous
     field on the line by ONE SPACE;  no  space	 should
     follow the	last field of a	line, and no other out-
     put should	be printed, except that	produced by the
     final XIT() command.

     End the program by	executing command "XIT();".

     Your  program  should  use	 fewer	than  1000  RMI
     istructions  per  number  processed, regardless of
     the size of that number.

     Use "submit_cps104	P3 FILE" to submit this	program.

     I found it	useful to  add	definitions  for  "ADD"	 and
"BNZ"  to  these, each defined in terms	of the above "given"
instructions:  (I assume the variables "Zero" and "M1"	have
previously  been  initialized to 0 and -1, respectively, and
that variable "t" has been declared.)

	#define	ADD(X,A,B) \
		SUB(t,Zero,B); \
		SUB(X,A,t);

	#define	BNZ(A,S) \
		BLTZ(A,S); \
		SUB(t,Zero,A);	\
		BLTZ(t,S);


     The "#defines" above can be copied	into  your  program,
making sure that the "#" sign appears in the first column of
the line. After	their occurrence in the	source text,  state-
ments  like  R("%d",q),	 and  ADD(q,r,4), can appear in	your
program.  Before using a particular variable, that  variable
must  be  declared, and	you can	use intialization to set its
initial	value to any constant, as in "int  i=1;".   The	 "\"
that  terminates  some lines in	the #defines "continues" the
definition to another line of input;  the"body"	of a #define
extends	 to  the end of	the current logical line of text. To
allow "define bodies" of several input	lines,	the  "\"  is
used to	end intermediate input lines that don't	end the	log-
ical line.

     To	return a  value	 from  a  subroutine  without  using
"return", try defining a global	variable into which the	sub-
routine	stores the value it wants to return.

     A statement STMNT in C can	be given a  label,  XXX,  by
writing

     XXX:    STMNT

     Then  executing  "goto  XXX;"  from  within  the	same









			   - 2 -


subroutine  causes  the	statement labeled XXX to be executed
next.