45 lines
1.4 KiB
C
45 lines
1.4 KiB
C
//===-- fixunsxfti.c - Implement __fixunsxfti -----------------------------===//
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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 __fixunsxfti for the compiler_rt library.
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//
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//===----------------------------------------------------------------------===//
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#include "int_lib.h"
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#ifdef CRT_HAS_128BIT
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// Returns: convert a to a unsigned long long, rounding toward zero.
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// Negative values all become zero.
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// Assumption: long double is an intel 80 bit floating point type padded with 6
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// bytes tu_int is a 128 bit integral type value in long double is representable
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// in tu_int or is negative
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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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COMPILER_RT_ABI tu_int __fixunsxfti(long double a) {
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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 || (fb.u.high.s.low & 0x00008000))
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return 0;
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if ((unsigned)e > sizeof(tu_int) * CHAR_BIT)
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return ~(tu_int)0;
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tu_int r = fb.u.low.all;
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if (e > 63)
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r <<= (e - 63);
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else
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r >>= (63 - e);
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return r;
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}
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#endif // CRT_HAS_128BIT
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