diff options
| author | Eric Andersen <andersen@codepoet.org> | 2001-10-02 10:45:16 +0000 |
|---|---|---|
| committer | Eric Andersen <andersen@codepoet.org> | 2001-10-02 10:45:16 +0000 |
| commit | f108799afa9b1d207e7139608c261f5546eb56bf (patch) | |
| tree | b84ad7a12eb961ca185c83b45098d5fc23ecd1ae /test/math/etodec.c | |
| parent | 04dafe547980c50bef57b3ea7a4f9e3d81400a87 (diff) | |
Add in some math lib tests
Diffstat (limited to 'test/math/etodec.c')
| -rw-r--r-- | test/math/etodec.c | 181 |
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
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