| 1 | //===-- fixxfdi.c - Implement __fixxfdi -----------------------------------===// |
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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 __fixxfdi for the compiler_rt library. |
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| 10 | // |
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| 11 | //===----------------------------------------------------------------------===// |
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| 12 | |
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| 13 | #if !_ARCH_PPC |
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| 14 | |
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| 15 | #include "int_lib.h" |
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| 16 | |
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| 17 | // Returns: convert a to a signed long long, rounding toward zero. |
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| 18 | |
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| 19 | // Assumption: long double is an intel 80 bit floating point type padded with 6 |
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| 20 | // bytes di_int is a 64 bit integral type value in long double is representable |
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| 21 | // in di_int (no range checking performed) |
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| 22 | |
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| 23 | // gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee |
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| 24 | // eeee | 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm |
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| 25 | // mmmm mmmm mmmm |
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| 26 | |
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| 27 | #if defined(_MSC_VER) && !defined(__clang__) |
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| 28 | // MSVC throws a warning about 'uninitialized variable use' here, |
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| 29 | // disable it for builds that warn-as-error |
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| 30 | #pragma warning(push) |
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| 31 | #pragma warning(disable : 4700) |
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| 32 | #endif |
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| 33 | |
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| 34 | COMPILER_RT_ABI di_int __fixxfdi(xf_float a) { |
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| 35 | const di_int di_max = (di_int)((~(du_int)0) / 2); |
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| 36 | const di_int di_min = -di_max - 1; |
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| 37 | xf_bits fb; |
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| 38 | fb.f = a; |
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| 39 | int e = (fb.u.high.s.low & 0x00007FFF) - 16383; |
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| 40 | if (e < 0) |
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| 41 | return 0; |
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| 42 | if ((unsigned)e >= sizeof(di_int) * CHAR_BIT) |
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| 43 | return a > 0 ? di_max : di_min; |
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| 44 | di_int s = -(si_int)((fb.u.high.s.low & 0x00008000) >> 15); |
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| 45 | di_int r = fb.u.low.all; |
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| 46 | r = (du_int)r >> (63 - e); |
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| 47 | return (r ^ s) - s; |
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| 48 | } |
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| 49 | |
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| 50 | #if defined(_MSC_VER) && !defined(__clang__) |
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| 51 | #pragma warning(pop) |
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| 52 | #endif |
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| 53 | |
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| 54 | #endif // !_ARCH_PPC |
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| 55 | |
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