forked from OSchip/llvm-project
55 lines
1.8 KiB
C
55 lines
1.8 KiB
C
//===-- fixxfdi.c - Implement __fixxfdi -----------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements __fixxfdi for the compiler_rt library.
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//
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//===----------------------------------------------------------------------===//
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#if !_ARCH_PPC
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#include "int_lib.h"
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// Returns: convert a to a signed long long, rounding toward zero.
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// Assumption: long double is an intel 80 bit floating point type padded with 6
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// bytes di_int is a 64 bit integral type value in long double is representable
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// in di_int (no range checking performed)
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// gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee
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// eeee | 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm
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// mmmm mmmm mmmm
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#if defined(_MSC_VER) && !defined(__clang__)
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// MSVC throws a warning about 'unitialized variable use' here,
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// disable it for builds that warn-as-error
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#pragma warning(push)
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#pragma warning(disable : 4700)
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#endif
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COMPILER_RT_ABI di_int __fixxfdi(long double a) {
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const di_int di_max = (di_int)((~(du_int)0) / 2);
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const di_int di_min = -di_max - 1;
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long_double_bits fb;
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fb.f = a;
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int e = (fb.u.high.s.low & 0x00007FFF) - 16383;
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if (e < 0)
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return 0;
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if ((unsigned)e >= sizeof(di_int) * CHAR_BIT)
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return a > 0 ? di_max : di_min;
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di_int s = -(si_int)((fb.u.high.s.low & 0x00008000) >> 15);
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di_int r = fb.u.low.all;
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r = (du_int)r >> (63 - e);
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return (r ^ s) - s;
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}
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#if defined(_MSC_VER) && !defined(__clang__)
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#pragma warning(pop)
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#endif
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#endif // !_ARCH_PPC
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