| 1 | /* |
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| 2 | * Double-precision math error handling. |
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| 3 | * |
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| 4 | * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 5 | * See https://llvm.org/LICENSE.txt for license information. |
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| 6 | * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 7 | */ |
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| 8 | |
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| 9 | #include "math_config.h" |
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| 10 | |
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| 11 | #if WANT_ERRNO |
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| 12 | #include <errno.h> |
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| 13 | /* NOINLINE reduces code size and avoids making math functions non-leaf |
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| 14 | when the error handling is inlined. */ |
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| 15 | NOINLINE static double |
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| 16 | with_errno (double y, int e) |
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| 17 | { |
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| 18 | errno = e; |
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| 19 | return y; |
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| 20 | } |
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| 21 | #else |
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| 22 | #define with_errno(x, e) (x) |
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| 23 | #endif |
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| 24 | |
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| 25 | /* NOINLINE reduces code size. */ |
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| 26 | NOINLINE static double |
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| 27 | xflow (uint32_t sign, double y) |
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| 28 | { |
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| 29 | y = eval_as_double (x: opt_barrier_double (x: sign ? -y : y) * y); |
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| 30 | return with_errno (y, ERANGE); |
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| 31 | } |
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| 32 | |
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| 33 | HIDDEN double |
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| 34 | __math_uflow (uint32_t sign) |
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| 35 | { |
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| 36 | return xflow (sign, y: 0x1p-767); |
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| 37 | } |
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| 38 | |
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| 39 | #if WANT_ERRNO_UFLOW |
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| 40 | /* Underflows to zero in some non-nearest rounding mode, setting errno |
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| 41 | is valid even if the result is non-zero, but in the subnormal range. */ |
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| 42 | HIDDEN double |
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| 43 | __math_may_uflow (uint32_t sign) |
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| 44 | { |
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| 45 | return xflow (sign, 0x1.8p-538); |
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| 46 | } |
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| 47 | #endif |
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| 48 | |
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| 49 | HIDDEN double |
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| 50 | __math_oflow (uint32_t sign) |
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| 51 | { |
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| 52 | return xflow (sign, y: 0x1p769); |
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| 53 | } |
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| 54 | |
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| 55 | HIDDEN double |
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| 56 | __math_divzero (uint32_t sign) |
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| 57 | { |
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| 58 | double y = opt_barrier_double (x: sign ? -1.0 : 1.0) / 0.0; |
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| 59 | return with_errno (y, ERANGE); |
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| 60 | } |
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| 61 | |
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| 62 | HIDDEN double |
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| 63 | __math_invalid (double x) |
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| 64 | { |
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| 65 | double y = (x - x) / (x - x); |
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| 66 | return isnan (x: x) ? y : with_errno (y, EDOM); |
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| 67 | } |
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| 68 | |
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| 69 | /* Check result and set errno if necessary. */ |
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| 70 | |
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| 71 | HIDDEN double |
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| 72 | __math_check_uflow (double y) |
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| 73 | { |
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| 74 | return y == 0.0 ? with_errno (y, ERANGE) : y; |
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| 75 | } |
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| 76 | |
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| 77 | HIDDEN double |
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| 78 | __math_check_oflow (double y) |
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| 79 | { |
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| 80 | return isinf (x: y) ? with_errno (y, ERANGE) : y; |
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| 81 | } |
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| 82 | |
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