diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/s_truncl.c')
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/s_truncl.c | 56 |
1 files changed, 16 insertions, 40 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_truncl.c b/sysdeps/ieee754/ldbl-128ibm/s_truncl.c index df58b64b53..a915a01ac6 100644 --- a/sysdeps/ieee754/ldbl-128ibm/s_truncl.c +++ b/sysdeps/ieee754/ldbl-128ibm/s_truncl.c @@ -1,6 +1,6 @@ /* Truncate (toward zero) long double floating-point values. IBM extended format long double version. - Copyright (C) 2006-2016 Free Software Foundation, Inc. + Copyright (C) 2006-2018 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -18,6 +18,7 @@ <http://www.gnu.org/licenses/>. */ #include <math.h> +#include <math_private.h> #include <math_ldbl_opt.h> #include <float.h> #include <ieee754.h> @@ -35,51 +36,26 @@ __truncl (long double x) && __builtin_isless (__builtin_fabs (xh), __builtin_inf ()), 1)) { - double orig_xh; - - /* Long double arithmetic, including the canonicalisation below, - only works in round-to-nearest mode. */ - - /* Convert the high double to integer. */ - orig_xh = xh; - hi = ldbl_nearbyint (xh); - - /* Subtract integral high part from the value. */ - xh -= hi; - ldbl_canonicalize (&xh, &xl); - - /* Now convert the low double, adjusted for any remainder from the - high double. */ - lo = ldbl_nearbyint (xh); - - /* Adjust the result when the remainder is non-zero. nearbyint - rounds values to the nearest integer, and values halfway - between integers to the nearest even integer. floorl must - round towards -Inf. */ - xh -= lo; - ldbl_canonicalize (&xh, &xl); - - if (orig_xh < 0.0) + hi = __trunc (xh); + if (hi != xh) { - if (xh > 0.0 || (xh == 0.0 && xl > 0.0)) - lo += 1.0; + /* The high part is not an integer; the low part does not + affect the result. */ + xh = hi; + xl = 0; } else { - if (xh < 0.0 || (xh == 0.0 && xl < 0.0)) - lo -= 1.0; + /* The high part is a nonzero integer. */ + lo = xh > 0 ? __floor (xl) : __ceil (xl); + xh = hi; + xl = lo; + ldbl_canonicalize_int (&xh, &xl); } - - /* Ensure the final value is canonical. In certain cases, - rounding causes hi,lo calculated so far to be non-canonical. */ - xh = hi; - xl = lo; - ldbl_canonicalize (&xh, &xl); - - /* Ensure we return -0 rather than +0 when appropriate. */ - if (orig_xh < 0.0) - xh = -__builtin_fabs (xh); } + else + /* Quiet signaling NaN arguments. */ + xh += xh; return ldbl_pack (xh, xl); } |