--- /dev/null
+/* Test file for mpfr_{mul,div}_2{ui,si}.
+
+Copyright 1999, 2001, 2002, 2003, 2004, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+Contributed by the Arenaire and Cacao projects, INRIA.
+
+This file is part of the GNU MPFR Library.
+
+The GNU MPFR Library is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or (at your
+option) any later version.
+
+The GNU MPFR Library is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with the GNU MPFR Library; see the file COPYING.LIB. If not, write to
+the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+MA 02110-1301, USA. */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "mpfr-test.h"
+
+static const char * const val[] = {
+ "1.0001@100","4.0004000000000@102", "4.0004000000000@97",
+ "1.ABF012345@-100","6.afc048d140000@-98","6.afc048d140000@-103",
+ "F.FFFFFFFFF@10000","3.fffffffffc000@10003","3.fffffffffc000@9998",
+ "1.23456789ABCDEF@42","4.8d159e26af37c@44","4.8d159e26af37c@39",
+ "17@42","5.c000000000000@45","5.c000000000000@40",
+ "42@-17","1.0800000000000@-13","1.0800000000000@-18"
+};
+
+static int
+test_mul (int i, int div, mpfr_ptr y, mpfr_srcptr x,
+ unsigned long int n, mp_rnd_t r)
+{
+ return
+ i == 0 ? (div ? mpfr_div_2ui : mpfr_mul_2ui) (y, x, n, r) :
+ i == 1 ? (div ? mpfr_div_2si : mpfr_mul_2si) (y, x, n, r) :
+ i == 2 ? (div ? mpfr_mul_2si : mpfr_div_2si) (y, x, -n, r) :
+ (exit (1), 0);
+}
+
+static void
+underflow (mp_exp_t e)
+{
+ mpfr_t x, y, z1, z2;
+ mp_exp_t emin;
+ int i, k;
+ int prec;
+ int rnd;
+ int div;
+ int inex1, inex2;
+ unsigned int flags1, flags2;
+
+ /* Test mul_2si(x, e - k), div_2si(x, k - e) and div_2ui(x, k - e)
+ * with emin = e, x = 1 + i/16, i in { -1, 0, 1 }, and k = 1 to 4,
+ * by comparing the result with the one of a simple division.
+ */
+ emin = mpfr_get_emin ();
+ set_emin (e);
+ mpfr_inits2 (8, x, y, (mpfr_ptr) 0);
+ for (i = 15; i <= 17; i++)
+ {
+ inex1 = mpfr_set_ui_2exp (x, i, -4, GMP_RNDN);
+ MPFR_ASSERTN (inex1 == 0);
+ for (prec = 6; prec >= 3; prec -= 3)
+ {
+ mpfr_inits2 (prec, z1, z2, (mpfr_ptr) 0);
+ RND_LOOP (rnd)
+ for (k = 1; k <= 4; k++)
+ {
+ /* The following one is assumed to be correct. */
+ inex1 = mpfr_mul_2si (y, x, e, GMP_RNDN);
+ MPFR_ASSERTN (inex1 == 0);
+ inex1 = mpfr_set_ui (z1, 1 << k, GMP_RNDN);
+ MPFR_ASSERTN (inex1 == 0);
+ mpfr_clear_flags ();
+ /* Do not use mpfr_div_ui to avoid the optimization
+ by mpfr_div_2si. */
+ inex1 = mpfr_div (z1, y, z1, (mpfr_rnd_t) rnd);
+ flags1 = __gmpfr_flags;
+
+ for (div = 0; div <= 2; div++)
+ {
+ mpfr_clear_flags ();
+ inex2 = div == 0 ?
+ mpfr_mul_2si (z2, x, e - k, (mpfr_rnd_t) rnd) : div == 1 ?
+ mpfr_div_2si (z2, x, k - e, (mpfr_rnd_t) rnd) :
+ mpfr_div_2ui (z2, x, k - e, (mpfr_rnd_t) rnd);
+ flags2 = __gmpfr_flags;
+ if (flags1 == flags2 && SAME_SIGN (inex1, inex2) &&
+ mpfr_equal_p (z1, z2))
+ continue;
+ printf ("Error in underflow(");
+ if (e == MPFR_EMIN_MIN)
+ printf ("MPFR_EMIN_MIN");
+ else if (e == emin)
+ printf ("default emin");
+ else
+ printf ("%ld", e);
+ printf (")\nwith %s, x = %d/16, prec = %d, k = %d, mpfr_%s",
+ div == 0 ? "mul_2si" : div == 1 ? "div_2si" :
+ "div_2ui", i, prec, k, mpfr_print_rnd_mode ((mpfr_rnd_t) rnd));
+ printf ("\nExpected ");
+ mpfr_out_str (stdout, 16, 0, z1, GMP_RNDN);
+ printf (", inex = %d, flags = %u\n", SIGN (inex1), flags1);
+ printf ("Got ");
+ mpfr_out_str (stdout, 16, 0, z2, GMP_RNDN);
+ printf (", inex = %d, flags = %u\n", SIGN (inex2), flags2);
+ exit (1);
+ } /* div */
+ } /* k */
+ mpfr_clears (z1, z2, (mpfr_ptr) 0);
+ } /* prec */
+ } /* i */
+ mpfr_clears (x, y, (mpfr_ptr) 0);
+ set_emin (emin);
+}
+
+static void
+underflow0 (void)
+{
+ underflow (-256);
+ if (mpfr_get_emin () != MPFR_EMIN_MIN)
+ underflow (mpfr_get_emin ());
+ underflow (MPFR_EMIN_MIN);
+}
+
+int
+main (int argc, char *argv[])
+{
+ mpfr_t w,z;
+ unsigned long k;
+ int i;
+
+ tests_start_mpfr ();
+
+ mpfr_inits2 (53, w, z, (mpfr_ptr) 0);
+
+ for (i = 0; i < 3; i++)
+ {
+ mpfr_set_inf (w, 1);
+ test_mul (i, 0, w, w, 10, GMP_RNDZ);
+ if (!MPFR_IS_INF(w))
+ {
+ printf ("Result is not Inf (i = %d)\n", i);
+ exit (1);
+ }
+
+ mpfr_set_nan (w);
+ test_mul (i, 0, w, w, 10, GMP_RNDZ);
+ if (!MPFR_IS_NAN(w))
+ {
+ printf ("Result is not NaN (i = %d)\n", i);
+ exit (1);
+ }
+
+ for (k = 0 ; k < numberof(val) ; k+=3)
+ {
+ mpfr_set_str (w, val[k], 16, GMP_RNDN);
+ test_mul (i, 0, z, w, 10, GMP_RNDZ);
+ if (mpfr_cmp_str (z, val[k+1], 16, GMP_RNDN))
+ {
+ printf ("ERROR for x * 2^n (i = %d) for %s\n", i, val[k]);
+ printf ("Expected: %s\n"
+ "Got : ", val[k+1]);
+ mpfr_out_str (stdout, 16, 0, z, GMP_RNDN);
+ putchar ('\n');
+ exit (1);
+ }
+ test_mul (i, 1, z, w, 10, GMP_RNDZ);
+ if (mpfr_cmp_str (z, val[k+2], 16, GMP_RNDN))
+ {
+ printf ("ERROR for x / 2^n (i = %d) for %s\n", i, val[k]);
+ printf ("Expected: %s\n"
+ "Got : ", val[k+2]);
+ mpfr_out_str (stdout, 16, 0, z, GMP_RNDN);
+ putchar ('\n');
+ exit (1);
+ }
+ }
+
+ mpfr_set_inf (w, 1);
+ mpfr_nextbelow (w);
+ test_mul (i, 0, w, w, 1, GMP_RNDN);
+ if (!mpfr_inf_p (w))
+ {
+ printf ("Overflow error (i = %d)!\n", i);
+ exit (1);
+ }
+ mpfr_set_ui (w, 0, GMP_RNDN);
+ mpfr_nextabove (w);
+ test_mul (i, 1, w, w, 1, GMP_RNDN);
+ if (mpfr_cmp_ui (w, 0))
+ {
+ printf ("Underflow error (i = %d)!\n", i);
+ exit (1);
+ }
+ }
+
+ if (MPFR_EXP_MAX >= LONG_MAX/2 && MPFR_EXP_MIN <= LONG_MAX/2-LONG_MAX-1)
+ {
+ unsigned long lmp1 = (unsigned long) LONG_MAX + 1;
+
+ mpfr_set_ui (w, 1, GMP_RNDN);
+ mpfr_mul_2ui (w, w, LONG_MAX/2, GMP_RNDZ);
+ mpfr_div_2ui (w, w, lmp1, GMP_RNDZ);
+ mpfr_mul_2ui (w, w, lmp1 - LONG_MAX/2, GMP_RNDZ);
+ if (!mpfr_cmp_ui (w, 1))
+ {
+ printf ("Underflow LONG_MAX error!\n");
+ exit (1);
+ }
+ }
+
+ mpfr_clears (w, z, (mpfr_ptr) 0);
+
+ underflow0 ();
+
+ tests_end_mpfr ();
+ return 0;
+}