mirror of git://gcc.gnu.org/git/gcc.git
131 lines
3.6 KiB
C
131 lines
3.6 KiB
C
/* Round argument to nearest integral value according to current rounding
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direction.
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Copyright (C) 1997-2018 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and
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Jakub Jelinek <jj@ultra.linux.cz>, 1999.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include "quadmath-imp.h"
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static const __float128 two112[2] =
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{
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5.19229685853482762853049632922009600E+33Q, /* 0x406F000000000000, 0 */
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-5.19229685853482762853049632922009600E+33Q /* 0xC06F000000000000, 0 */
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};
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long int
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lrintq (__float128 x)
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{
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int32_t j0;
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uint64_t i0,i1;
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__float128 w;
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__float128 t;
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long int result;
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int sx;
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GET_FLT128_WORDS64 (i0, i1, x);
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j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
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sx = i0 >> 63;
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i0 &= 0x0000ffffffffffffLL;
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i0 |= 0x0001000000000000LL;
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if (j0 < (int32_t) (8 * sizeof (long int)) - 1)
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{
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if (j0 < 48)
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{
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#if defined FE_INVALID || defined FE_INEXACT
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/* X < LONG_MAX + 1 implied by J0 < 31. */
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if (sizeof (long int) == 4
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&& x > (__float128) LONG_MAX)
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{
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/* In the event of overflow we must raise the "invalid"
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exception, but not "inexact". */
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t = nearbyintq (x);
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feraiseexcept (t == LONG_MAX ? FE_INEXACT : FE_INVALID);
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}
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else
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#endif
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{
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w = two112[sx] + x;
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t = w - two112[sx];
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}
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GET_FLT128_WORDS64 (i0, i1, t);
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j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
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i0 &= 0x0000ffffffffffffLL;
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i0 |= 0x0001000000000000LL;
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result = (j0 < 0 ? 0 : i0 >> (48 - j0));
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}
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else if (j0 >= 112)
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result = ((long int) i0 << (j0 - 48)) | (i1 << (j0 - 112));
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else
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{
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#if defined FE_INVALID || defined FE_INEXACT
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/* X < LONG_MAX + 1 implied by J0 < 63. */
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if (sizeof (long int) == 8
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&& x > (__float128) LONG_MAX)
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{
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/* In the event of overflow we must raise the "invalid"
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exception, but not "inexact". */
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t = nearbyintq (x);
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feraiseexcept (t == LONG_MAX ? FE_INEXACT : FE_INVALID);
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}
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else
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#endif
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{
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w = two112[sx] + x;
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t = w - two112[sx];
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}
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GET_FLT128_WORDS64 (i0, i1, t);
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j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
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i0 &= 0x0000ffffffffffffLL;
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i0 |= 0x0001000000000000LL;
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if (j0 == 48)
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result = (long int) i0;
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else
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result = ((long int) i0 << (j0 - 48)) | (i1 >> (112 - j0));
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}
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}
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else
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{
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/* The number is too large. Unless it rounds to LONG_MIN,
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FE_INVALID must be raised and the return value is
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unspecified. */
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#if defined FE_INVALID || defined FE_INEXACT
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if (x < (__float128) LONG_MIN
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&& x > (__float128) LONG_MIN - 1)
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{
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/* If truncation produces LONG_MIN, the cast will not raise
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the exception, but may raise "inexact". */
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t = nearbyintq (x);
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feraiseexcept (t == LONG_MIN ? FE_INEXACT : FE_INVALID);
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return LONG_MIN;
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}
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else if (FIX_FLT128_LONG_CONVERT_OVERFLOW && x != (__float128) LONG_MIN)
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{
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feraiseexcept (FE_INVALID);
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return sx == 0 ? LONG_MAX : LONG_MIN;
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}
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#endif
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return (long int) x;
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}
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return sx ? -result : result;
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}
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