1  /* Return classification value corresponding to argument.
       2     Copyright (C) 1997-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <math.h>
      20  
      21  #include <math_private.h>
      22  #include <math_ldbl_opt.h>
      23  
      24    /*
      25     *		hx                  lx
      26     * +NaN	7ffn nnnn nnnn nnnn xxxx xxxx xxxx xxxx
      27     * -NaN	fffn nnnn nnnn nnnn xxxx xxxx xxxx xxxx
      28     * +Inf	7ff0 0000 0000 0000 xxxx xxxx xxxx xxxx
      29     * -Inf	fff0 0000 0000 0000 xxxx xxxx xxxx xxxx
      30     * +0		0000 0000 0000 0000 xxxx xxxx xxxx xxxx
      31     * -0		8000 0000 0000 0000 xxxx xxxx xxxx xxxx
      32     * +normal	0360 0000 0000 0000 0000 0000 0000 0000 (smallest)
      33     * -normal	8360 0000 0000 0000 0000 0000 0000 0000 (smallest)
      34     * +normal	7fef ffff ffff ffff 7c8f ffff ffff fffe (largest)
      35     * +normal	ffef ffff ffff ffff fc8f ffff ffff fffe (largest)
      36     * +denorm	0360 0000 0000 0000 8000 0000 0000 0001 (largest)
      37     * -denorm	8360 0000 0000 0000 0000 0000 0000 0001 (largest)
      38     * +denorm	000n nnnn nnnn nnnn xxxx xxxx xxxx xxxx
      39     * -denorm	800n nnnn nnnn nnnn xxxx xxxx xxxx xxxx
      40     */
      41  
      42  int
      43  ___fpclassifyl (long double x)
      44  {
      45    uint64_t hx, lx;
      46    int retval = FP_NORMAL;
      47    double xhi, xlo;
      48  
      49    ldbl_unpack (x, &xhi, &xlo);
      50    EXTRACT_WORDS64 (hx, xhi);
      51    if ((hx & 0x7ff0000000000000ULL) == 0x7ff0000000000000ULL) {
      52        /* +/-NaN or +/-Inf */
      53        if (hx & 0x000fffffffffffffULL) {
      54  	  /* +/-NaN */
      55  	  retval = FP_NAN;
      56        } else {
      57  	  retval = FP_INFINITE;
      58        }
      59    } else {
      60        /* +/-zero or +/- normal or +/- denormal */
      61        if (hx & 0x7fffffffffffffffULL) {
      62  	  /* +/- normal or +/- denormal */
      63  	  if ((hx & 0x7ff0000000000000ULL) > 0x0360000000000000ULL) {
      64  	      /* +/- normal */
      65  	      retval = FP_NORMAL;
      66  	  } else {
      67  	      if ((hx & 0x7ff0000000000000ULL) == 0x0360000000000000ULL) {
      68  		  EXTRACT_WORDS64 (lx, xlo);
      69  		  if ((lx & 0x7fffffffffffffff)	/* lower is non-zero */
      70  		  && ((lx^hx) & 0x8000000000000000ULL)) { /* and sign differs */
      71  		      /* +/- denormal */
      72  		      retval = FP_SUBNORMAL;
      73  		  } else {
      74  		      /* +/- normal */
      75  		      retval = FP_NORMAL;
      76  		  }
      77  	      } else {
      78  		  /* +/- denormal */
      79  		  retval = FP_SUBNORMAL;
      80  	      }
      81  	  }
      82        } else {
      83  	  /* +/- zero */
      84  	  retval = FP_ZERO;
      85        }
      86    }
      87  
      88    return retval;
      89  }
      90  long_double_symbol (libm, ___fpclassifyl, __fpclassifyl);
      91  #ifdef __LONG_DOUBLE_MATH_OPTIONAL
      92  libm_hidden_ver (___fpclassifyl, __fpclassifyl)
      93  #else
      94  libm_hidden_def (__fpclassifyl)
      95  #endif