1 /* Test mpf_sqrt_ui. 2 3 Copyright 2004 Free Software Foundation, Inc. 4 5 This file is part of the GNU MP Library. 6 7 The GNU MP Library is free software; you can redistribute it and/or modify 8 it under the terms of the GNU Lesser General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or (at your 10 option) any later version. 11 12 The GNU MP Library is distributed in the hope that it will be useful, but 13 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 15 License for more details. 16 17 You should have received a copy of the GNU Lesser General Public License 18 along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */ 19 20 #include <stdio.h> 21 #include <stdlib.h> 22 23 #include "gmp.h" 24 #include "gmp-impl.h" 25 #include "tests.h" 26 27 28 void 29 check_rand (void) 30 { 31 unsigned long max_prec = 15; 32 unsigned long min_prec = __GMPF_BITS_TO_PREC (1); 33 gmp_randstate_ptr rands = RANDS; 34 unsigned long x, prec; 35 mpf_t r, s; 36 int i; 37 38 mpf_init (r); 39 mpf_init (s); 40 refmpf_set_prec_limbs (s, 2*max_prec+10); 41 42 for (i = 0; i < 50; i++) 43 { 44 /* input, a random non-zero ulong, exponentially distributed */ 45 do { 46 x = gmp_urandomb_ui (rands, 47 gmp_urandomm_ui (rands, BITS_PER_ULONG) + 1); 48 } while (x == 0); 49 50 /* result precision */ 51 prec = gmp_urandomm_ui (rands, max_prec-min_prec) + min_prec; 52 refmpf_set_prec_limbs (r, prec); 53 54 mpf_sqrt_ui (r, x); 55 MPF_CHECK_FORMAT (r); 56 57 /* Expect to prec limbs of result. 58 In the current implementation there's no stripping of low zero 59 limbs in mpf_sqrt_ui, not even on perfect squares, so size should 60 be exactly prec. */ 61 if (SIZ(r) != prec) 62 { 63 printf ("mpf_sqrt_ui result not enough result limbs\n"); 64 printf (" x=%lu\n", x); 65 printf (" want prec=%lu\n", prec); 66 mpf_trace (" r", r); 67 printf (" r size %ld\n", (long) SIZ(r)); 68 printf (" r prec %ld\n", (long) PREC(r)); 69 abort (); 70 } 71 72 /* Must have r^2 <= x, since r has been truncated. */ 73 mpf_mul (s, r, r); 74 if (! (mpf_cmp_ui (s, x) <= 0)) 75 { 76 printf ("mpf_sqrt_ui result too big\n"); 77 printf (" x=%lu\n", x); 78 printf (" want prec=%lu\n", prec); 79 mpf_trace (" r", r); 80 mpf_trace (" s", s); 81 abort (); 82 } 83 84 /* Must have (r+ulp)^2 > x. 85 No overflow from refmpf_add_ulp since r is only prec limbs. */ 86 refmpf_add_ulp (r); 87 mpf_mul (s, r, r); 88 if (! (mpf_cmp_ui (s, x) > 0)) 89 { 90 printf ("mpf_sqrt_ui result too small\n"); 91 printf (" x=%lu\n", x); 92 printf (" want prec=%lu\n", prec); 93 mpf_trace (" r+ulp", r); 94 mpf_trace (" s", s); 95 abort (); 96 } 97 } 98 99 mpf_clear (r); 100 mpf_clear (s); 101 } 102 103 int 104 main (int argc, char **argv) 105 { 106 tests_start (); 107 mp_trace_base = -16; 108 109 check_rand (); 110 111 tests_end (); 112 exit (0); 113 } 114