1 files changed, 181 insertions, 0 deletions
diff --git a/test/math/etodec.c b/test/math/etodec.c
new file mode 100644
index 000000000..29fee34cd
--- /dev/null
+++ b/test/math/etodec.c
@@ -0,0 +1,181 @@
+#include "ehead.h"
+void emovi(), emovo(), ecleaz(), eshdn8(), emdnorm();
+void todec();
+/*
+;	convert DEC double precision to e type
+;	double d;
+;	short e[NE];
+;	dectoe( &d, e );
+*/
+void dectoe( d, e )
+unsigned short *d;
+unsigned short *e;
+{
+unsigned short y[NI];
+register unsigned short r, *p;
+
+ecleaz(y);		/* start with a zero */
+p = y;			/* point to our number */
+r = *d;			/* get DEC exponent word */
+if( *d & (unsigned int )0x8000 )
+	*p = 0xffff;	/* fill in our sign */
+++p;			/* bump pointer to our exponent word */
+r &= 0x7fff;		/* strip the sign bit */
+if( r == 0 )		/* answer = 0 if high order DEC word = 0 */
+	goto done;
+
+
+r >>= 7;	/* shift exponent word down 7 bits */
+r += EXONE - 0201;	/* subtract DEC exponent offset */
+			/* add our e type exponent offset */
+*p++ = r;	/* to form our exponent */
+
+r = *d++;	/* now do the high order mantissa */
+r &= 0177;	/* strip off the DEC exponent and sign bits */
+r |= 0200;	/* the DEC understood high order mantissa bit */
+*p++ = r;	/* put result in our high guard word */
+
+*p++ = *d++;	/* fill in the rest of our mantissa */
+*p++ = *d++;
+*p = *d;
+
+eshdn8(y);	/* shift our mantissa down 8 bits */
+done:
+emovo( y, e );
+}
+
+
+
+/*
+;	convert e type to DEC double precision
+;	double d;
+;	short e[NE];
+;	etodec( e, &d );
+*/
+#if 0
+static unsigned short decbit[NI] = {0,0,0,0,0,0,0200,0};
+void etodec( x, d )
+unsigned short *x, *d;
+{
+unsigned short xi[NI];
+register unsigned short r;
+int i, j;
+
+emovi( x, xi );
+*d = 0;
+if( xi[0] != 0 )
+	*d = 0100000;
+r = xi[E];
+if( r < (EXONE - 128) )
+	goto zout;
+i = xi[M+4];
+if( (i & 0200) != 0 )
+	{
+	if( (i & 0377) == 0200 )
+		{
+		if( (i & 0400) != 0 )
+			{
+		/* check all less significant bits */
+			for( j=M+5; j<NI; j++ )
+				{
+				if( xi[j] != 0 )
+					goto yesrnd;
+				}
+			}
+		goto nornd;
+		}
+yesrnd:
+	eaddm( decbit, xi );
+	r -= enormlz(xi);
+	}
+
+nornd:
+
+r -= EXONE;
+r += 0201;
+if( r < 0 )
+	{
+zout:
+	*d++ = 0;
+	*d++ = 0;
+	*d++ = 0;
+	*d++ = 0;
+	return;
+	}
+if( r >= 0377 )
+	{
+	*d++ = 077777;
+	*d++ = -1;
+	*d++ = -1;
+	*d++ = -1;
+	return;
+	}
+r &= 0377;
+r <<= 7;
+eshup8( xi );
+xi[M] &= 0177;
+r |= xi[M];
+*d++ |= r;
+*d++ = xi[M+1];
+*d++ = xi[M+2];
+*d++ = xi[M+3];
+}
+#else
+
+extern int rndprc;
+
+void etodec( x, d )
+unsigned short *x, *d;
+{
+unsigned short xi[NI];
+long exp;
+int rndsav;
+
+emovi( x, xi );
+exp = (long )xi[E] - (EXONE - 0201); /* adjust exponent for offsets */
+/* round off to nearest or even */
+rndsav = rndprc;
+rndprc = 56;
+emdnorm( xi, 0, 0, exp, 64 );
+rndprc = rndsav;
+todec( xi, d );
+}
+
+void todec( x, y )
+unsigned short *x, *y;
+{
+unsigned short i;
+unsigned short *p;
+
+p = x;
+*y = 0;
+if( *p++ )
+	*y = 0100000;
+i = *p++;
+if( i == 0 )
+	{
+	*y++ = 0;
+	*y++ = 0;
+	*y++ = 0;
+	*y++ = 0;
+	return;
+	}
+if( i > 0377 )
+	{
+	*y++ |= 077777;
+	*y++ = 0xffff;
+	*y++ = 0xffff;
+	*y++ = 0xffff;
+	return;
+	}
+i &= 0377;
+i <<= 7;
+eshup8( x );
+x[M] &= 0177;
+i |= x[M];
+*y++ |= i;
+*y++ = x[M+1];
+*y++ = x[M+2];
+*y++ = x[M+3];
+}
+#endif