1  /* Round a float value to a long long in the current rounding mode.
       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  #include <math_private.h>
      21  #include <stdint.h>
      22  #include <libm-alias-float.h>
      23  
      24  long long int
      25  __llrintf (float x)
      26  {
      27  #ifdef _ARCH_PWR4
      28    /* Assume powerpc64 instructions availability.  */
      29    long long int ret;
      30    __asm__ ("fctid %0, %1" : "=d" (ret) : "d" (x));
      31    return ret;
      32  #else
      33    float rx = rintf (x);
      34    if (HAVE_PPC_FCTIDZ || rx != x)
      35      return (long long int) rx;
      36    else
      37      {
      38        float arx = fabsf (rx);
      39        /* Avoid incorrect exceptions from libgcc conversions (as of GCC
      40  	 5): <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59412>.  */
      41        if (arx < 0x1p31f)
      42  	return (long long int) (long int) rx;
      43        else if (!(arx < 0x1p55f))
      44  	return (long long int) (long int) (rx * 0x1p-32f) << 32;
      45        uint32_t i0;
      46        GET_FLOAT_WORD (i0, rx);
      47        int exponent = ((i0 >> 23) & 0xff) - 0x7f;
      48        unsigned long long int mant = (i0 & 0x7fffff) | 0x800000;
      49        mant <<= exponent - 23;
      50        return (long long int) ((i0 & 0x80000000) != 0 ? -mant : mant);
      51      }
      52  #endif
      53  }
      54  libm_alias_float (__llrint, llrint)