[ba11ebb] | 1 | /*
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[b69786e] | 2 | * Copyright (c) 2015 Jiri Svoboda
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[ba11ebb] | 3 | * All rights reserved.
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| 4 | *
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| 5 | * Redistribution and use in source and binary forms, with or without
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| 6 | * modification, are permitted provided that the following conditions
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| 7 | * are met:
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| 8 | *
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| 9 | * - Redistributions of source code must retain the above copyright
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| 10 | * notice, this list of conditions and the following disclaimer.
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| 11 | * - Redistributions in binary form must reproduce the above copyright
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| 12 | * notice, this list of conditions and the following disclaimer in the
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| 13 | * documentation and/or other materials provided with the distribution.
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| 14 | * - The name of the author may not be used to endorse or promote products
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| 15 | * derived from this software without specific prior written permission.
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| 16 | *
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 27 | */
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| 28 |
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| 29 | /** @addtogroup libmath
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| 30 | * @{
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| 31 | */
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| 32 | /** @file
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| 33 | */
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| 34 |
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[b69786e] | 35 | #include <errno.h>
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| 36 | #include <ldexp.h>
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| 37 | #include <math.h>
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[ba11ebb] | 38 |
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[b69786e] | 39 | /** Single precision multiply by power of two
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| 40 | *
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| 41 | * Compute x * 2^exp.
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| 42 | *
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| 43 | * @param x Number
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| 44 | * @param exp Exponent
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| 45 | *
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| 46 | * @return x * 2^exp
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| 47 | *
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| 48 | */
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| 49 | float32_t float32_ldexp(float32_t x, int exp)
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| 50 | {
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| 51 | float32_u u;
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| 52 | int e;
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| 53 |
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| 54 | u.val = x;
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| 55 | e = u.data.parts.exp + exp;
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| 56 |
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| 57 | if (e < 0) {
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| 58 | /* XXX Can we return denormalized numbers? */
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| 59 | return 0.0;
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| 60 | } else if (e > FLOAT32_MAX_EXPONENT) {
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| 61 | errno = ERANGE;
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| 62 | if (e < 0)
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| 63 | return -FLOAT32_INF;
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| 64 | else
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| 65 | return FLOAT32_INF;
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| 66 | } else {
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| 67 | /* Adjust exponent */
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| 68 | u.data.parts.exp = e;
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| 69 | return u.val;
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| 70 | }
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| 71 | }
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| 72 |
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| 73 | /** Double precision multiply by power of two
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| 74 | *
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| 75 | * Compute x * 2^exp.
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| 76 | *
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| 77 | * @param x Number
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| 78 | * @param y Exponent
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| 79 | *
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| 80 | * @return x * 2^exp
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| 81 | *
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| 82 | */
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| 83 | float64_t float64_ldexp(float64_t x, int exp)
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| 84 | {
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| 85 | float64_u u;
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| 86 | int e;
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| 87 |
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| 88 | u.val = x;
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| 89 | e = u.data.parts.exp + exp;
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[ba11ebb] | 90 |
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[b69786e] | 91 | if (e < 0) {
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| 92 | /* XXX Can we return denormalized numbers? */
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| 93 | return 0.0;
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| 94 | } else if (e > FLOAT64_MAX_EXPONENT) {
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| 95 | errno = ERANGE;
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| 96 | if (e < 0)
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| 97 | return -FLOAT64_INF;
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| 98 | else
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| 99 | return FLOAT64_INF;
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| 100 | } else {
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| 101 | /* Adjust exponent */
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| 102 | u.data.parts.exp = e;
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| 103 | return u.val;
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| 104 | }
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| 105 | }
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[ba11ebb] | 106 |
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| 107 | /** @}
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| 108 | */
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