diff options
Diffstat (limited to 'sysdeps/ieee754/dbl-64/s_lrint.c')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/s_lrint.c | 51 |
1 files changed, 43 insertions, 8 deletions
diff --git a/sysdeps/ieee754/dbl-64/s_lrint.c b/sysdeps/ieee754/dbl-64/s_lrint.c index 9cce37f3cf..4e7cbef97b 100644 --- a/sysdeps/ieee754/dbl-64/s_lrint.c +++ b/sysdeps/ieee754/dbl-64/s_lrint.c @@ -1,6 +1,6 @@ /* Round argument to nearest integral value according to current rounding direction. - Copyright (C) 1997-2015 Free Software Foundation, Inc. + Copyright (C) 1997-2016 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. @@ -18,9 +18,12 @@ License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ +#include <fenv.h> +#include <limits.h> #include <math.h> #include <math_private.h> +#include <fix-fp-int-convert-overflow.h> static const double two52[2] = { @@ -34,7 +37,7 @@ __lrint (double x) { int32_t j0; u_int32_t i0, i1; - volatile double w; + double w; double t; long int result; int sx; @@ -47,7 +50,7 @@ __lrint (double x) if (j0 < 20) { - w = two52[sx] + x; + w = math_narrow_eval (two52[sx] + x); t = w - two52[sx]; EXTRACT_WORDS (i0, i1, t); j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; @@ -59,11 +62,25 @@ __lrint (double x) else if (j0 < (int32_t) (8 * sizeof (long int)) - 1) { if (j0 >= 52) - result = ((long int) i0 << (j0 - 20)) | (i1 << (j0 - 52)); + result = ((long int) i0 << (j0 - 20)) | ((long int) i1 << (j0 - 52)); else { - w = two52[sx] + x; - t = w - two52[sx]; +#if defined FE_INVALID || defined FE_INEXACT + /* X < LONG_MAX + 1 implied by J0 < 31. */ + if (sizeof (long int) == 4 + && x > (double) LONG_MAX) + { + /* In the event of overflow we must raise the "invalid" + exception, but not "inexact". */ + t = __nearbyint (x); + feraiseexcept (t == LONG_MAX ? FE_INEXACT : FE_INVALID); + } + else +#endif + { + w = math_narrow_eval (two52[sx] + x); + t = w - two52[sx]; + } EXTRACT_WORDS (i0, i1, t); j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; i0 &= 0xfffff; @@ -77,8 +94,26 @@ __lrint (double 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 (sizeof (long int) == 4 + && x < (double) LONG_MIN + && x > (double) LONG_MIN - 1.0) + { + /* If truncation produces LONG_MIN, the cast will not raise + the exception, but may raise "inexact". */ + t = __nearbyint (x); + feraiseexcept (t == LONG_MIN ? FE_INEXACT : FE_INVALID); + return LONG_MIN; + } + else if (FIX_DBL_LONG_CONVERT_OVERFLOW && x != (double) LONG_MIN) + { + feraiseexcept (FE_INVALID); + return sx == 0 ? LONG_MAX : LONG_MIN; + } +#endif return (long int) x; } |