arithmetic/src/basictypes/integer/IntegerTrans.i3

INTERFACE IntegerTrans;
Arithmetic for Modula-3, see doc for details

Abstract: Generic computations on integer types

2/17/96 Harry George Initial version 

 Integer Approximations 




PROCEDURE SqRt (N: [0 .. 1073741823]; ): CARDINAL;

 returns integer sqrt of N. 
 CORDIC Functions 


CONST
  CordicBits   = 16;
  CordicBase   = 65536;          (* 2^CordicBits *)
  CordicHalf   = CordicBase DIV 2;
  RadToCordic  = 4.172151340188181D+4; (* 0..+pi/2-->cordicbase *)
  CordicToReal = 1.52587890625D-5; (* cordicbase -->0..1 *)

TYPE Cordic = [0 .. CordicBase * 4];

PROCEDURE SinCos (theta: Cordic; VAR s, c: INTEGER; );

 compute sin and cos of theta and write results to s and c 
* E.g.:
  theta:=ROUND(theta_in_radians*RadToCordic);
  sin_cos(theta:=theta,s:=s,c:=c);
  sin_in_radians:=FLOAT(s,REAL64)*UnitPerCordic;
  cos_in_radians:=FLOAT(c,REAL64)*UnitPerCordic;
Of course, in real life you wouldn't be moving in and out
of floating point.  theta would be computed in cordics to begin with.
Thus 100*sin(theta) is obtained by:
  sin_cos(theta:=theta,s:=s,c:=c);
  answer:=Word.RightShift(100*s + CordicHalf),CordicBits);



END IntegerTrans.