diff options
Diffstat (limited to 'libquadmath/math/lrintq.c')
| -rw-r--r-- | libquadmath/math/lrintq.c | 84 |
1 files changed, 65 insertions, 19 deletions
diff --git a/libquadmath/math/lrintq.c b/libquadmath/math/lrintq.c index d1497ae..50a3005 100644 --- a/libquadmath/math/lrintq.c +++ b/libquadmath/math/lrintq.c @@ -1,9 +1,9 @@ /* Round argument to nearest integral value according to current rounding direction. - Copyright (C) 1997, 1999, 2004, 2006 Free Software Foundation, Inc. + Copyright (C) 1997-2017 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and - Jakub Jelinek <jj@ultra.linux.cz>, 1999. + Jakub Jelinek <jj@ultra.linux.cz>, 1999. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public @@ -33,7 +33,7 @@ lrintq (__float128 x) { int32_t j0; uint64_t i0,i1; - volatile __float128 w; + __float128 w; __float128 t; long int result; int sx; @@ -44,25 +44,57 @@ lrintq (__float128 x) i0 &= 0x0000ffffffffffffLL; i0 |= 0x0001000000000000LL; - if (j0 < 48) + if (j0 < (int32_t) (8 * sizeof (long int)) - 1) { - w = two112[sx] + x; - t = w - two112[sx]; - GET_FLT128_WORDS64 (i0, i1, t); - j0 = ((i0 >> 48) & 0x7fff) - 0x3fff; - i0 &= 0x0000ffffffffffffLL; - i0 |= 0x0001000000000000LL; + if (j0 < 48) + { +#if defined FE_INVALID || defined FE_INEXACT + /* X < LONG_MAX + 1 implied by J0 < 31. */ + if (sizeof (long int) == 4 + && x > (__float128) LONG_MAX) + { + /* In the event of overflow we must raise the "invalid" + exception, but not "inexact". */ + t = nearbyintq (x); +#ifdef USE_FENV_H + feraiseexcept (t == LONG_MAX ? FE_INEXACT : FE_INVALID); +#endif + } + else +#endif + { + w = two112[sx] + x; + t = w - two112[sx]; + } + GET_FLT128_WORDS64 (i0, i1, t); + j0 = ((i0 >> 48) & 0x7fff) - 0x3fff; + i0 &= 0x0000ffffffffffffLL; + i0 |= 0x0001000000000000LL; - result = (j0 < 0 ? 0 : i0 >> (48 - j0)); - } - else if (j0 < (int32_t) (8 * sizeof (long int)) - 1) - { - if (j0 >= 112) + result = (j0 < 0 ? 0 : i0 >> (48 - j0)); + } + else if (j0 >= 112) result = ((long int) i0 << (j0 - 48)) | (i1 << (j0 - 112)); else { - w = two112[sx] + x; - t = w - two112[sx]; +#if defined FE_INVALID || defined FE_INEXACT + /* X < LONG_MAX + 1 implied by J0 < 63. */ + if (sizeof (long int) == 8 + && x > (__float128) LONG_MAX) + { + /* In the event of overflow we must raise the "invalid" + exception, but not "inexact". */ + t = nearbyintq (x); +#ifdef USE_FENV_H + feraiseexcept (t == LONG_MAX ? FE_INEXACT : FE_INVALID); +#endif + } + else +#endif + { + w = two112[sx] + x; + t = w - two112[sx]; + } GET_FLT128_WORDS64 (i0, i1, t); j0 = ((i0 >> 48) & 0x7fff) - 0x3fff; i0 &= 0x0000ffffffffffffLL; @@ -76,8 +108,22 @@ lrintq (__float128 x) } else { - /* The number is too large. It is left implementation defined - what happens. */ + /* The number is too large. Unless it rounds to LONG_MIN, + FE_INVALID must be raised and the return value is + unspecified. */ +#if defined FE_INVALID || defined FE_INEXACT + if (x < (__float128) LONG_MIN + && x > (__float128) LONG_MIN - 1.0Q) + { + /* If truncation produces LONG_MIN, the cast will not raise + the exception, but may raise "inexact". */ + t = nearbyintq (x); +#ifdef USE_FENV_H + feraiseexcept (t == LONG_MIN ? FE_INEXACT : FE_INVALID); +#endif + return LONG_MIN; + } +#endif return (long int) x; } |