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https://github.com/jerryscript-project/jerryscript.git
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3ba286f3e1
* Rename modified fdlibm to jerry-libm
* Move third-party/fdlibm to jerry-libm
* Rename original fdlibm.h to jerry-libm-internal.h
* And remove it from the public headers.
* Rename jerry-libm's public header to math.h
* This also makes jerry-core sources include `<math.h>`. Therefore,
should anyone want to use a different libm implementation with
jerry, it becomes possible. (The same way as we provide a minimal
libc with standard headers, but should it be insufficient or
conflicting for someone, it can be replaced.)
* Drop `s_` prefix from jerry-libm sources
* The original fdlibm implementation had various prefixes (e.g., `k_`
for sources of kernel routines, and `w_` for wrapper routines), but
after the specialization of fdlibm to jerry, only `s_` remained.
Since it does not encode anything anymore, it can be dropped.
* Stylistic edits to jerry-libm's CMakeLists
* Align project name with other CMakeLists in the code base
* Move Jerry-LibM under Apache License
* Using the same approach as was used by linux-wireless when ath5k
driver license needed clarification. Solution was proposed by SFLC.
External mail for future reference: http://lwn.net/Articles/247806/
* Tests & checks
* Remove FD from the name of libm unit test-related files
* Make vera++ and cppcheck check jerry-libm
* Targets
* Speculative update of targets to use jerry-libm
JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu
92 lines
2.4 KiB
C
92 lines
2.4 KiB
C
/* Copyright 2016 Samsung Electronics Co., Ltd.
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* Copyright 2016 University of Szeged
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* This file is based on work under the following copyright and permission
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* notice:
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*
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunSoft, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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*
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* @(#)s_scalbn.c 1.3 95/01/18
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*/
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#include "jerry-libm-internal.h"
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/* scalbn(x,n) returns x* 2**n computed by exponent
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* manipulation rather than by actually performing an
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* exponentiation or a multiplication.
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*/
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#define two54 1.80143985094819840000e+16 /* 0x43500000, 0x00000000 */
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#define twom54 5.55111512312578270212e-17 /* 0x3C900000, 0x00000000 */
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#define huge 1.0e+300
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#define tiny 1.0e-300
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double
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scalbn (double x, int n)
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{
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int k, hx, lx;
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hx = __HI (x);
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lx = __LO (x);
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k = (hx & 0x7ff00000) >> 20; /* extract exponent */
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if (k == 0) /* 0 or subnormal x */
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{
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if ((lx | (hx & 0x7fffffff)) == 0) /* +-0 */
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{
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return x;
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}
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x *= two54;
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hx = __HI (x);
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k = ((hx & 0x7ff00000) >> 20) - 54;
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if (n < -50000) /*underflow */
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{
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return tiny * x;
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}
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}
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if (k == 0x7ff) /* NaN or Inf */
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{
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return x + x;
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}
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k = k + n;
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if (k > 0x7fe) /* overflow */
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{
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return huge * copysign (huge, x);
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}
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if (k > 0) /* normal result */
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{
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__HI (x) = (hx & 0x800fffff) | (k << 20);
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return x;
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}
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if (k <= -54)
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{
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if (n > 50000) /* in case integer overflow in n + k */
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{
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return huge * copysign (huge, x); /*overflow */
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}
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else
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{
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return tiny * copysign (tiny, x); /*underflow */
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}
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}
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k += 54; /* subnormal result */
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__HI (x) = (hx & 0x800fffff) | (k << 20);
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return x * twom54;
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} /* scalbn */
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