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-rw-r--r--libm/double/fltest.c272
1 files changed, 272 insertions, 0 deletions
diff --git a/libm/double/fltest.c b/libm/double/fltest.c
new file mode 100644
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+++ b/libm/double/fltest.c
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+/* fltest.c
+ * Test program for floor(), frexp(), ldexp()
+ */
+
+/*
+Cephes Math Library Release 2.1: December, 1988
+Copyright 1984, 1987, 1988 by Stephen L. Moshier
+Direct inquiries to 30 Frost Street, Cambridge, MA 02140
+*/
+
+
+
+#include <math.h>
+extern double MACHEP;
+#define UTH -1023
+
+main()
+{
+double x, y, y0, z, f, x00, y00;
+int i, j, k, e, e0;
+int errfr, errld, errfl, underexp, err, errth, e00;
+double frexp(), ldexp(), floor();
+
+
+/*
+if( 1 )
+ goto flrtst;
+*/
+
+printf( "Testing frexp() and ldexp().\n" );
+errfr = 0;
+errld = 0;
+underexp = 0;
+f = 1.0;
+x00 = 2.0;
+y00 = 0.5;
+e00 = 2;
+
+for( j=0; j<20; j++ )
+{
+if( j == 10 )
+ {
+ f = 1.0;
+ x00 = 2.0;
+ e00 = 1;
+/* Find 2**(2**10) / 2 */
+#ifdef DEC
+ for( i=0; i<5; i++ )
+#else
+ for( i=0; i<9; i++ )
+#endif
+ {
+ x00 *= x00;
+ e00 += e00;
+ }
+ y00 = x00/2.0;
+ x00 = x00 * y00;
+ e00 += e00;
+ y00 = 0.5;
+ }
+x = x00 * f;
+y0 = y00 * f;
+e0 = e00;
+for( i=0; i<2200; i++ )
+ {
+ x /= 2.0;
+ e0 -= 1;
+ if( x == 0.0 )
+ {
+ if( f == 1.0 )
+ underexp = e0;
+ y0 = 0.0;
+ e0 = 0;
+ }
+ y = frexp( x, &e );
+ if( (e0 < -1023) && (e != e0) )
+ {
+ if( e == (e0 - 1) )
+ {
+ e += 1;
+ y /= 2.0;
+ }
+ if( e == (e0 + 1) )
+ {
+ e -= 1;
+ y *= 2.0;
+ }
+ }
+ err = y - y0;
+ if( y0 != 0.0 )
+ err /= y0;
+ if( err < 0.0 )
+ err = -err;
+ if( e0 > -1023 )
+ errth = 0.0;
+ else
+ {/* Denormal numbers may have rounding errors */
+ if( e0 == -1023 )
+ {
+ errth = 2.0 * MACHEP;
+ }
+ else
+ {
+ errth *= 2.0;
+ }
+ }
+
+ if( (x != 0.0) && ((err > errth) || (e != e0)) )
+ {
+ printf( "Test %d: ", j+1 );
+ printf( " frexp( %.15e) =?= %.15e * 2**%d;", x, y, e );
+ printf( " should be %.15e * 2**%d\n", y0, e0 );
+ errfr += 1;
+ }
+ y = ldexp( x, 1-e0 );
+ err = y - 1.0;
+ if( err < 0.0 )
+ err = -err;
+ if( (err > errth) && ((x == 0.0) && (y != 0.0)) )
+ {
+ printf( "Test %d: ", j+1 );
+ printf( "ldexp( %.15e, %d ) =?= %.15e;", x, 1-e0, y );
+ if( x != 0.0 )
+ printf( " should be %.15e\n", f );
+ else
+ printf( " should be %.15e\n", 0.0 );
+ errld += 1;
+ }
+ if( x == 0.0 )
+ {
+ break;
+ }
+ }
+f = f * 1.08005973889;
+}
+
+
+x = 2.22507385850720138309e-308;
+for (i = 0; i < 52; i++)
+ {
+ y = ldexp (x, -i);
+ z = ldexp (y, i);
+ if (x != z)
+ {
+ printf ("x %.16e, i %d, y %.16e, z %.16e\n", x, i, y, z);
+ errld += 1;
+ }
+ }
+
+
+if( (errld == 0) && (errfr == 0) )
+ {
+ printf( "No errors found.\n" );
+ }
+
+flrtst:
+
+printf( "Testing floor().\n" );
+errfl = 0;
+
+f = 1.0/MACHEP;
+x00 = 1.0;
+for( j=0; j<57; j++ )
+{
+x = x00 - 1.0;
+for( i=0; i<128; i++ )
+ {
+ y = floor(x);
+ if( y != x )
+ {
+ flierr( x, y, j );
+ errfl += 1;
+ }
+/* Warning! the if() statement is compiler dependent,
+ * since x-0.49 may be held in extra precision accumulator
+ * so would never compare equal to x! The subroutine call
+ * y = floor() forces z to be stored as a double and reloaded
+ * for the if() statement.
+ */
+ z = x - 0.49;
+ y = floor(z);
+ if( z == x )
+ break;
+ if( y != (x - 1.0) )
+ {
+ flierr( z, y, j );
+ errfl += 1;
+ }
+
+ z = x + 0.49;
+ y = floor(z);
+ if( z != x )
+ {
+ if( y != x )
+ {
+ flierr( z, y, j );
+ errfl += 1;
+ }
+ }
+ x = -x;
+ y = floor(x);
+ if( z != x )
+ {
+ if( y != x )
+ {
+ flierr( x, y, j );
+ errfl += 1;
+ }
+ }
+ z = x + 0.49;
+ y = floor(z);
+ if( z != x )
+ {
+ if( y != x )
+ {
+ flierr( z, y, j );
+ errfl += 1;
+ }
+ }
+ z = x - 0.49;
+ y = floor(z);
+ if( z != x )
+ {
+ if( y != (x - 1.0) )
+ {
+ flierr( z, y, j );
+ errfl += 1;
+ }
+ }
+ x = -x;
+ x += 1.0;
+ }
+x00 = x00 + x00;
+}
+y = floor(0.0);
+if( y != 0.0 )
+ {
+ flierr( 0.0, y, 57 );
+ errfl += 1;
+ }
+y = floor(-0.0);
+if( y != 0.0 )
+ {
+ flierr( -0.0, y, 58 );
+ errfl += 1;
+ }
+y = floor(-1.0);
+if( y != -1.0 )
+ {
+ flierr( -1.0, y, 59 );
+ errfl += 1;
+ }
+y = floor(-0.1);
+if( y != -1.0 )
+ {
+ flierr( -0.1, y, 60 );
+ errfl += 1;
+ }
+
+if( errfl == 0 )
+ printf( "No errors found in floor().\n" );
+
+}
+
+
+flierr( x, y, k )
+double x, y;
+int k;
+{
+printf( "Test %d: ", k+1 );
+printf( "floor(%.15e) =?= %.15e\n", x, y );
+}