improved/speeded up using new ecvt

diff --git a/lang/m2/libm2/RealConver.mod b/lang/m2/libm2/RealConver.mod
index eac853e..f3795a3 100644 (file)
--- a/lang/m2/libm2/RealConver.mod
+++ b/lang/m2/libm2/RealConver.mod
@@ -11,7 +11,6 @@ IMPLEMENTATION MODULE RealConversions;
   Version:      $Header$
 *)
 
-  FROM EM IMPORT FIF;
 
   PROCEDURE RealToString(arg: REAL;
                width, digits: INTEGER;
@@ -21,6 +20,15 @@ IMPLEMENTATION MODULE RealConversions;
        LongRealToString(LONG(arg), width, digits, str, ok);
   END RealToString;
 
+  TYPE
+       Powers = RECORD
+               pval: LONGREAL;
+               rpval: LONGREAL;
+               exp: INTEGER
+       END;
+
+  VAR Powers10: ARRAY[1..6] OF Powers;
+
   PROCEDURE LongRealToString(arg: LONGREAL;
                width, digits: INTEGER;
                VAR str: ARRAY OF CHAR;
@@ -28,12 +36,10 @@ IMPLEMENTATION MODULE RealConversions;
     VAR        pointpos: INTEGER;
        i: CARDINAL;
        ecvtflag: BOOLEAN;
-       r, intpart, fractpart: LONGREAL;
+       r: LONGREAL;
        ind1, ind2 : CARDINAL;
        sign: BOOLEAN;
-       tmp : CHAR;
        ndigits: CARDINAL;
-       dummy, dig: LONGREAL;
 
   BEGIN
        r := arg;
@@ -50,62 +56,37 @@ IMPLEMENTATION MODULE RealConversions;
        pointpos := 0;
        sign := r < 0.0D;
        IF sign THEN r := -r END;
-       r := FIF(r, 1.0D, intpart);
-       fractpart := r;
-       pointpos := 0;
-       ind1 := 0;
-       ok := TRUE;
-       (*
-         Do integer part, which is now in "intpart". "r" now contains the
-         fraction part.
-       *)
-       IF intpart # 0.0D THEN
-               ind2 := 0;
-               WHILE intpart # 0.0D DO
-                       IF ind2 > HIGH(str) THEN
-                               IF NOT ecvtflag THEN
-                                       str[0] := 0C;
-                                       ok := FALSE;
-                                       RETURN;
+       IF r # 0.0D THEN
+               IF r >= 10.0D THEN
+                       FOR i := 1 TO 6 DO
+                               WITH Powers10[i] DO
+                                       WHILE r >= pval DO
+                                               r := r * rpval;
+                                               INC(pointpos, exp)
+                                       END;
                                END;
-                               FOR ind1 := 1 TO HIGH(str) DO
-                                       str[ind1-1] := str[ind1];
-                               END;
-                               DEC(ind2);
-                       END;
-                       dummy := FIF(FIF(intpart, 0.1D, intpart),10.0D, dig);
-                       IF (dummy > 0.5D) AND (dig < 9.0D) THEN
-                               dig := dig + 1.0D;
                        END;
-                       str[ind2] := CHR(TRUNC(dig+0.5D) + ORD('0'));
-                       INC(ind2);
-                       INC(pointpos);
-               END;
-               i := 0;
-               ind1 := ind2;
-               WHILE ind2 > i DO
-                       DEC(ind2);
-                       tmp := str[i];
-                       str[i] := str[ind2];
-                       str[ind2] := tmp;
-                       INC(i);
                END;
-       ELSE
-               INC(pointpos);
-               IF r > 0.0D THEN
-                       WHILE r < 1.0D DO
-                               fractpart := r;
-                               r := r * 10.0D;
-                               DEC(pointpos);
+               IF r < 1.0D THEN
+                       FOR i := 1 TO 6 DO
+                               WITH Powers10[i] DO
+                                       WHILE r*pval < 10.0D DO
+                                               r := r * pval;
+                                               DEC(pointpos, exp)
+                                       END;
+                               END;
                        END;
                END;
+               (* Now, we have r in [1.0, 10.0) *)
+               INC(pointpos);
        END;
-       ind2 := ndigits;
+       ind1 := 0;
+       ok := TRUE;
+       ind2 := ndigits+1;
+
        IF NOT ecvtflag THEN 
                IF INTEGER(ind2) + pointpos < 0 THEN
-                       ind2 := ndigits;
-                       FOR i := 0 TO ndigits DO str[i] := '0'; END;
-                       ind1 := ndigits+1;
+                       ind2 := 0;
                ELSE
                        ind2 := INTEGER(ind2) + pointpos
                END;
@@ -115,24 +96,27 @@ IMPLEMENTATION MODULE RealConversions;
                str[0] := 0C;
                RETURN;
        END;
-       WHILE ind1 <= ind2 DO
-               fractpart := FIF(fractpart, 10.0D, r);
+       WHILE ind1 < ind2 DO
                str[ind1] := CHR(TRUNC(r)+ORD('0'));
+               r := 10.0D * (r - FLOATD(TRUNC(r)));
                INC(ind1);
        END;
-       ind1 := ind2;
-       str[ind2] := CHR(ORD(str[ind2])+5);
-       WHILE str[ind2] > '9' DO
-               str[ind2] := '0';
-               IF ind2 > 0 THEN
-                       DEC(ind2);
-                       str[ind2] := CHR(ORD(str[ind2])+1);
-               ELSE
-                       str[ind2] := '1';
-                       INC(pointpos);
-                       IF NOT ecvtflag THEN
-                               IF ind1 > 0 THEN str[ind1] := '0'; END;
-                               INC(ind1);
+       IF ind2 > 0 THEN
+               DEC(ind2);
+               ind1 := ind2;
+               str[ind2] := CHR(ORD(str[ind2])+5);
+               WHILE str[ind2] > '9' DO
+                       str[ind2] := '0';
+                       IF ind2 > 0 THEN
+                               DEC(ind2);
+                               str[ind2] := CHR(ORD(str[ind2])+1);
+                       ELSE
+                               str[ind2] := '1';
+                               INC(pointpos);
+                               IF NOT ecvtflag THEN
+                                       IF ind1 > 0 THEN str[ind1] := '0'; END;
+                                       INC(ind1);
+                               END;
                        END;
                END;
        END;
@@ -329,4 +313,11 @@ IMPLEMENTATION MODULE RealConversions;
        IF (iB <= HIGH(str)) AND (ORD(ch) > ORD(' ')) THEN ok := FALSE; END
   END StringToLongReal;
 
+BEGIN
+       WITH Powers10[1] DO pval := 1.0D32; rpval := 1.0D-32; exp := 32 END;
+       WITH Powers10[2] DO pval := 1.0D16; rpval := 1.0D-16; exp := 16 END;
+       WITH Powers10[3] DO pval := 1.0D8; rpval := 1.0D-8; exp := 8 END;
+       WITH Powers10[4] DO pval := 1.0D4; rpval := 1.0D-4; exp := 4 END;
+       WITH Powers10[5] DO pval := 1.0D2; rpval := 1.0D-2; exp := 2 END;
+       WITH Powers10[6] DO pval := 1.0D1; rpval := 1.0D-1; exp := 1 END;
 END RealConversions.