| 1 | //===--- lib/builtins/ppc/fixtfti.c - Convert long double->int128 *-C -*---===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | // This file implements converting the 128bit IBM/PowerPC long double (double- |
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| 10 | // double) data type to a signed 128 bit integer. |
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| 11 | // |
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| 12 | //===----------------------------------------------------------------------===// |
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| 13 | |
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| 14 | #include "../int_math.h" |
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| 15 | |
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| 16 | // Convert long double into a signed 128-bit integer. |
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| 17 | __int128_t __fixtfti(long double input) { |
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| 18 | |
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| 19 | // If we are trying to convert a NaN, return the NaN bit pattern. |
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| 20 | if (crt_isnan(input)) { |
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| 21 | return ((__uint128_t)0x7FF8000000000000ll) << 64 | |
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| 22 | (__uint128_t)0x0000000000000000ll; |
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| 23 | } |
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| 24 | |
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| 25 | // Note: overflow is an undefined behavior for this conversion. |
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| 26 | // For this reason, overflow is not checked here. |
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| 27 | |
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| 28 | // If the long double is negative, use unsigned conversion from its absolute |
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| 29 | // value. |
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| 30 | if (input < 0.0) { |
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| 31 | __uint128_t result = (__uint128_t)(-input); |
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| 32 | return -((__int128_t)result); |
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| 33 | } |
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| 34 | |
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| 35 | // Otherwise, use unsigned conversion from the input value. |
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| 36 | __uint128_t result = (__uint128_t)input; |
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| 37 | return result; |
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| 38 | } |
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| 39 | |
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