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109 lines
3.1 KiB
C
109 lines
3.1 KiB
C
/* Test of rounding to nearest, breaking ties away from zero.
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Copyright (C) 2007-2008 Free Software Foundation, Inc.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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/* Written by Ben Pfaff <blp@gnu.org>, 2007.
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Heavily based on code by Bruno Haible. */
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/* Get the two reference implementations of round under the names
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round_reference1 and round_reference2.
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round.c will #include <config.h> for us. */
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#define FLOOR_BASED_ROUND round_reference1
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#define FLOOR_FREE_ROUND round_reference2
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#include "round.c"
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#include <math.h>
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#include <float.h>
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#include <stdbool.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include "verify.h"
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#ifdef USE_LONG_DOUBLE
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# error Long double not supported.
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#elif ! defined USE_FLOAT
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# include "isnand.h"
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# define ISNAN isnand
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# define FUNCTION "round"
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# define DOUBLE_UINT uint64_t
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# define DOUBLE_BITS 64
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# define NUM_HIGHBITS 13
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# define NUM_LOWBITS 4
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#else /* defined USE_FLOAT */
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# include "isnanf.h"
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# define ISNAN isnanf
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# define FUNCTION "roundf"
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# define DOUBLE_UINT uint32_t
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# define DOUBLE_BITS 32
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# define NUM_HIGHBITS 12
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# define NUM_LOWBITS 4
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#endif
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/* Test for equality. */
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static bool
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equal (const char *message, DOUBLE x, DOUBLE y0, DOUBLE y1)
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{
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if (ISNAN (y0) ? ISNAN (y1) : y0 == y1)
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return true;
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else
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{
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fprintf (stderr, "%s: "FUNCTION"(%g(%a)) = %g(%a) or %g(%a)?\n",
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message, x, x, y0, y0, y1, y1);
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return false;
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}
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}
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/* Test the function for a given argument. */
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static bool
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check (DOUBLE x)
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{
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DOUBLE ref1 = round_reference1 (x);
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DOUBLE ref2 = round_reference2 (x);
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DOUBLE result = ROUND (x);
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/* If the reference implementations disagree, bail out immediately. */
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if (!equal ("reference implementations disagree", x, ref1, ref2))
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exit (EXIT_FAILURE);
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/* If the actual implementation is wrong, return an error code. */
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return equal ("bad round implementation", x, ref1, result);
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}
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int
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main (void)
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{
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DOUBLE_UINT highbits, lowbits;
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int error = 0;
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for (highbits = 0; highbits < (1 << NUM_HIGHBITS); highbits++)
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for (lowbits = 0; lowbits < (1 << NUM_LOWBITS); lowbits++)
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{
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/* Combine highbits and lowbits into a floating-point number,
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sign-extending the lowbits to DOUBLE_BITS-NUM_HIGHBITS bits. */
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union { DOUBLE f; DOUBLE_UINT i; } janus;
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verify (sizeof janus.f == sizeof janus.i);
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janus.i = lowbits | (highbits << (DOUBLE_BITS - NUM_HIGHBITS));
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if (lowbits >> (NUM_LOWBITS - 1))
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janus.i |= ((DOUBLE_UINT) -1
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>> (NUM_LOWBITS + NUM_HIGHBITS)
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<< NUM_LOWBITS);
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if (!check (janus.f))
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error = true;
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}
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return (error ? 1 : 0);
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}
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