1 /* Round a float value to a long long in the current rounding mode.
2    Copyright (C) 1997-2021 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
__llrintf(float x)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)
55