| 1 | /* Single-precision math error handling. |
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| 2 | Copyright (c) 2017 ARM Ltd. All rights reserved. |
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| 3 | |
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| 4 | Redistribution and use in source and binary forms, with or without |
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| 5 | modification, are permitted provided that the following conditions |
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| 6 | are met: |
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| 7 | 1. Redistributions of source code must retain the above copyright |
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| 8 | notice, this list of conditions and the following disclaimer. |
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| 9 | 2. Redistributions in binary form must reproduce the above copyright |
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| 10 | notice, this list of conditions and the following disclaimer in the |
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| 11 | documentation and/or other materials provided with the distribution. |
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| 12 | 3. The name of the company may not be used to endorse or promote |
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| 13 | products derived from this software without specific prior written |
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| 14 | permission. |
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| 15 | |
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| 16 | THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS AND ANY EXPRESS OR IMPLIED |
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| 17 | WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
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| 18 | MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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| 19 | IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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| 20 | SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED |
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| 21 | TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
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| 22 | PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
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| 23 | LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
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| 24 | NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
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| 25 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ |
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| 26 | |
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| 27 | #include "fdlibm.h" |
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| 28 | #if !__OBSOLETE_MATH |
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| 29 | |
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| 30 | #include "math_config.h" |
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| 31 | |
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| 32 | #if WANT_ERRNO |
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| 33 | #include <errno.h> |
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| 34 | /* NOINLINE reduces code size and avoids making math functions non-leaf |
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| 35 | when the error handling is inlined. */ |
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| 36 | NOINLINE static float |
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| 37 | with_errnof (float y, int e) |
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| 38 | { |
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| 39 | errno = e; |
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| 40 | return y; |
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| 41 | } |
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| 42 | #else |
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| 43 | #define with_errnof(x, e) (x) |
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| 44 | #endif |
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| 45 | |
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| 46 | /* NOINLINE prevents fenv semantics breaking optimizations. */ |
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| 47 | NOINLINE static float |
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| 48 | xflowf (unsigned long sign, float y) |
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| 49 | { |
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| 50 | y = (sign ? -y : y) * y; |
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| 51 | return with_errnof (y, ERANGE); |
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| 52 | } |
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| 53 | |
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| 54 | HIDDEN float |
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| 55 | __math_uflowf (unsigned long sign) |
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| 56 | { |
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| 57 | return xflowf (sign, 0x1p-95f); |
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| 58 | } |
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| 59 | |
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| 60 | #if WANT_ERRNO_UFLOW |
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| 61 | /* Underflows to zero in some non-nearest rounding mode, setting errno |
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| 62 | is valid even if the result is non-zero, but in the subnormal range. */ |
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| 63 | HIDDEN float |
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| 64 | __math_may_uflowf (unsigned long sign) |
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| 65 | { |
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| 66 | return xflowf (sign, 0x1.4p-75f); |
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| 67 | } |
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| 68 | #endif |
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| 69 | |
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| 70 | HIDDEN float |
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| 71 | __math_oflowf (unsigned long sign) |
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| 72 | { |
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| 73 | return xflowf (sign, 0x1p97f); |
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| 74 | } |
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| 75 | |
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| 76 | HIDDEN float |
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| 77 | __math_divzerof (unsigned long sign) |
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| 78 | { |
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| 79 | float y = 0; |
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| 80 | return with_errnof ((sign ? -1 : 1) / y, ERANGE); |
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| 81 | } |
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| 82 | |
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| 83 | HIDDEN float |
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| 84 | __math_invalidf (float x) |
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| 85 | { |
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| 86 | float y = (x - x) / (x - x); |
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| 87 | return isnan (x) ? y : with_errnof (y, EDOM); |
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| 88 | } |
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| 89 | #endif /* !__OBSOLETE_MATH */ |
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