/* mpfr_tlgamma -- test file for lgamma function

Copyright 2005, 2006, 2007 Free Software Foundation, Inc.
Contributed by the Arenaire and Cacao projects, INRIA.

This file is part of the MPFR Library.

The 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 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 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 int
mpfr_lgamma_nosign (mpfr_ptr y, mpfr_srcptr x, mp_rnd_t rnd)
{
  int inex, sign;

  inex = mpfr_lgamma (y, &sign, x, rnd);
  if (!MPFR_IS_SINGULAR (y))
    {
      MPFR_ASSERTN (sign == 1 || sign == -1);
      if (sign == -1 && (rnd == GMP_RNDN || rnd == GMP_RNDZ))
        mpfr_neg (y, y, GMP_RNDN);
      /* This is a way to check that the sign is consistent. */
    }

  return inex;
}

#define TEST_FUNCTION mpfr_lgamma_nosign
#include "tgeneric.c"

static void
special (void)
{
  mpfr_t x, y;
  int inex;
  int sign;

  mpfr_init (x);
  mpfr_init (y);

  mpfr_set_nan (x);
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  if (!mpfr_nan_p (y))
    {
      printf ("Error for lgamma(NaN)\n");
      exit (1);
    }

  mpfr_set_inf (x, -1);
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  if (!mpfr_inf_p (y) || mpfr_sgn (y) < 0)
    {
      printf ("Error for lgamma(-Inf)\n");
      exit (1);
    }

  mpfr_set_inf (x, 1);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  if (!mpfr_inf_p (y) || mpfr_sgn (y) < 0 || sign != 1)
    {
      printf ("Error for lgamma(+Inf)\n");
      exit (1);
    }

  mpfr_set_ui (x, 0, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  if (!mpfr_inf_p (y) || mpfr_sgn (y) < 0 || sign != 1)
    {
      printf ("Error for lgamma(+0)\n");
      exit (1);
    }

  mpfr_set_ui (x, 0, GMP_RNDN);
  mpfr_neg (x, x, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  if (!mpfr_inf_p (y) || mpfr_sgn (y) < 0 || sign != -1)
    {
      printf ("Error for lgamma(-0)\n");
      exit (1);
    }

  mpfr_set_ui (x, 1, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  if (MPFR_IS_NAN (y) || mpfr_cmp_ui (y, 0) || MPFR_IS_NEG (y) || sign != 1)
    {
      printf ("Error for lgamma(1)\n");
      exit (1);
    }

  mpfr_set_si (x, -1, GMP_RNDN);
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  if (!mpfr_inf_p (y) || mpfr_sgn (y) < 0)
    {
      printf ("Error for lgamma(-1)\n");
      exit (1);
    }

  mpfr_set_ui (x, 2, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  if (MPFR_IS_NAN (y) || mpfr_cmp_ui (y, 0) || MPFR_IS_NEG (y) || sign != 1)
    {
      printf ("Error for lgamma(2)\n");
      exit (1);
    }

  mpfr_set_prec (x, 53);
  mpfr_set_prec (y, 53);

#define CHECK_X1 "1.0762904832837976166"
#define CHECK_Y1 "-0.039418362817587634939"

  mpfr_set_str (x, CHECK_X1, 10, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_str (x, CHECK_Y1, 10, GMP_RNDN);
  if (MPFR_IS_NAN (y) || mpfr_cmp (y, x) || sign != 1)
    {
      printf ("mpfr_lgamma("CHECK_X1") is wrong:\n"
              "expected ");
      mpfr_print_binary (x); putchar ('\n');
      printf ("got      ");
      mpfr_print_binary (y); putchar ('\n');
      exit (1);
    }

#define CHECK_X2 "9.23709516716202383435e-01"
#define CHECK_Y2 "0.049010669407893718563"
  mpfr_set_str (x, CHECK_X2, 10, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_str (x, CHECK_Y2, 10, GMP_RNDN);
  if (MPFR_IS_NAN (y) || mpfr_cmp (y, x) || sign != 1)
    {
      printf ("mpfr_lgamma("CHECK_X2") is wrong:\n"
              "expected ");
      mpfr_print_binary (x); putchar ('\n');
      printf ("got      ");
      mpfr_print_binary (y); putchar ('\n');
      exit (1);
    }

  mpfr_set_prec (x, 8);
  mpfr_set_prec (y, 175);
  mpfr_set_ui (x, 33, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDU);
  mpfr_set_prec (x, 175);
  mpfr_set_str_binary (x, "0.1010001100011101101011001101110010100001000001000001110011000001101100001111001001000101011011100100010101011110100111110101010100010011010010000101010111001100011000101111E7");
  if (MPFR_IS_NAN (y) || mpfr_cmp (x, y) || sign != 1)
    {
      printf ("Error in mpfr_lgamma (1)\n");
      exit (1);
    }

  mpfr_set_prec (x, 21);
  mpfr_set_prec (y, 8);
  mpfr_set_ui (y, 120, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (x, &sign, y, GMP_RNDZ);
  mpfr_set_prec (y, 21);
  mpfr_set_str_binary (y, "0.111000101000001100101E9");
  if (MPFR_IS_NAN (x) || mpfr_cmp (x, y) || sign != 1)
    {
      printf ("Error in mpfr_lgamma (120)\n");
      printf ("Expected "); mpfr_print_binary (y); puts ("");
      printf ("Got      "); mpfr_print_binary (x); puts ("");
      exit (1);
    }

  mpfr_set_prec (x, 3);
  mpfr_set_prec (y, 206);
  mpfr_set_str_binary (x, "0.110e10");
  sign = -17;
  inex = mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_prec (x, 206);
  mpfr_set_str_binary (x, "0.10000111011000000011100010101001100110001110000111100011000100100110110010001011011110101001111011110110000001010100111011010000000011100110110101100111000111010011110010000100010111101010001101000110101001E13");
  if (MPFR_IS_NAN (y) || mpfr_cmp (x, y) || sign != 1)
    {
      printf ("Error in mpfr_lgamma (768)\n");
      exit (1);
    }
  if (inex >= 0)
    {
      printf ("Wrong flag for mpfr_lgamma (768)\n");
      exit (1);
    }

  mpfr_set_prec (x, 4);
  mpfr_set_prec (y, 4);
  mpfr_set_str_binary (x, "0.1100E-66");
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_str_binary (x, "0.1100E6");
  if (MPFR_IS_NAN (y) || mpfr_cmp (x, y) || sign != 1)
    {
      printf ("Error for lgamma(0.1100E-66)\n");
      exit (1);
    }

  mpfr_set_prec (x, 256);
  mpfr_set_prec (y, 32);
  mpfr_set_si_2exp (x, -1, 200, GMP_RNDN);
  mpfr_add_ui (x, x, 1, GMP_RNDN);
  mpfr_div_2ui (x, x, 1, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_prec (x, 32);
  mpfr_set_str_binary (x, "-0.10001000111011111011000010100010E207");
  if (MPFR_IS_NAN (y) || mpfr_cmp (x, y) || sign != 1)
    {
      printf ("Error for lgamma(-2^199+0.5)\n");
      printf ("Got        ");
      mpfr_dump (y);
      printf ("instead of ");
      mpfr_dump (x);
      exit (1);
    }

  mpfr_set_prec (x, 256);
  mpfr_set_prec (y, 32);
  mpfr_set_si_2exp (x, -1, 200, GMP_RNDN);
  mpfr_sub_ui (x, x, 1, GMP_RNDN);
  mpfr_div_2ui (x, x, 1, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_prec (x, 32);
  mpfr_set_str_binary (x, "-0.10001000111011111011000010100010E207");
  if (MPFR_IS_NAN (y) || mpfr_cmp (x, y) || sign != -1)
    {
      printf ("Error for lgamma(-2^199-0.5)\n");
      printf ("Got        ");
      mpfr_dump (y);
      printf ("with sign %d instead of ", sign);
      mpfr_dump (x);
      printf ("with sign -1.\n");
      exit (1);
    }

  mpfr_clear (x);
  mpfr_clear (y);
}

int
main (void)
{
  tests_start_mpfr ();

  special ();
  test_generic (2, 100, 2);

  tests_end_mpfr ();
  return 0;
}