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author | Jeff Johnston <jjohnstn@redhat.com> | 2014-12-15 20:50:23 +0000 |
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committer | Jeff Johnston <jjohnstn@redhat.com> | 2014-12-15 20:50:23 +0000 |
commit | 705cda717ee7ae28c490c51ba80b55fcd38fb210 (patch) | |
tree | 316cd5736d21e59425eef58eeee7928fdd4c29c6 /newlib/libm/common/nexttowardf.c | |
parent | f97bf8a679600a097ef0aa963e8d7295f95e6937 (diff) | |
download | cygnal-705cda717ee7ae28c490c51ba80b55fcd38fb210.tar.gz cygnal-705cda717ee7ae28c490c51ba80b55fcd38fb210.tar.bz2 cygnal-705cda717ee7ae28c490c51ba80b55fcd38fb210.zip |
2014-12-15 Jonathan Roelofs <jonathan@codesourcery.com>
* libc/include/math.h: Add log2l,logbl,nexttowardf,
* nexttoward,nexttowardl
* libm/common/Makefile.am: Reference new files
* libm/common/Makefile.in: Reference new files
* libm/common/log2l.c: New File
* libm/common/logbl.c: Likewise
* libm/common/nexttowardf.c: Likewise
* libm/common/nexttoward.c: Likewise
* libm/common/nexttowardl.c: Likewise
Diffstat (limited to 'newlib/libm/common/nexttowardf.c')
-rw-r--r-- | newlib/libm/common/nexttowardf.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/newlib/libm/common/nexttowardf.c b/newlib/libm/common/nexttowardf.c new file mode 100644 index 000000000..6f473190f --- /dev/null +++ b/newlib/libm/common/nexttowardf.c @@ -0,0 +1,78 @@ +/* + * Copyright © 2005-2014 Rich Felker, et al. + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY + * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, + * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE + * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ + +#include <math.h> +#include <inttypes.h> +#include "local.h" + +union fshape { + float value; + uint32_t bits; +}; + +// This is only necessary because the implementation of isnan only works +// properly when long double == double. +// See: https://sourceware.org/ml/newlib/2014/msg00684.html +#ifdef _LDBL_EQ_DOUBLE + +float +nexttowardf (float x, long double y) +{ + union fshape ux; + uint32_t e; + + if (isnan(x) || isnan(y)) + return x + y; + if (x == y) + return y; + ux.value = x; + if (x == 0) { + ux.bits = 1; + if (signbit(y)) + ux.bits |= 0x80000000; + } else if (x < y) { + if (signbit(x)) + ux.bits--; + else + ux.bits++; + } else { + if (signbit(x)) + ux.bits++; + else + ux.bits--; + } + e = ux.bits & 0x7f800000; + /* raise overflow if ux.value is infinite and x is finite */ + if (e == 0x7f800000) { + volatile float force_eval; + force_eval = x + x; + } + /* raise underflow if ux.value is subnormal or zero */ + if (e == 0) { + volatile float force_eval; + force_eval = x*x + ux.value*ux.value; + } + return ux.value; +} + +#endif // _LDBL_EQ_DOUBLE |