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Diffstat (limited to 'sysdeps/powerpc/q_dtoq.c')
-rw-r--r-- | sysdeps/powerpc/q_dtoq.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/sysdeps/powerpc/q_dtoq.c b/sysdeps/powerpc/q_dtoq.c new file mode 100644 index 0000000000..8cab9e4689 --- /dev/null +++ b/sysdeps/powerpc/q_dtoq.c @@ -0,0 +1,66 @@ +/* 64-bit floating point to 128-bit floating point. + Copyright (C) 1997 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 + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <quad_float.h> + +/* long double _q_dtoq(double a); + Convert 'a' to long double. Don't raise exceptions. + */ + +void +__q_dtoq(unsigned long long result[2], double a) +{ + unsigned ux, rx; + union { + double d; + unsigned long long u; + } u; + + u.d = a; + result[1] = u.u << 64-4; + result[0] = u.u >> 4; + /* correct exponent bias */ + rx = ((long long)u.u >> 52 & 0x87ff) + 16383-1023; + + ux = u.u >> 52 & 0x7ff; + if (ux == 0) + { + if ((u.u & 0x7fffffffffffffffULL) == 0) + { + /* +0.0 or -0.0. */ + rx &= 0x8000; + } + else + { + /* Denormalised number. Renormalise. */ + unsigned long long um = u.u & 0x000fffffffffffffULL; + int cs = cntlzd(um) - 12 + 1; + rx -= cs; + um <<= cs; + result[0] = um >> 4; + result[1] = um << 64-4; + } + } + else if (ux == 0x7ff) + { + /* Inf or NaN. */ + rx |= 0x7fff; + } + *(unsigned short *)result = rx; +} |