50 lines
1.4 KiB
C
50 lines
1.4 KiB
C
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/* ===-- fixunsxfti.c - Implement __fixunsxfti -----------------------------===
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*
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* The LLVM Compiler Infrastructure
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*
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* This file is dual licensed under the MIT and the University of Illinois Open
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* Source Licenses. See LICENSE.TXT for details.
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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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*/
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#include "int_lib.h"
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#if __x86_64
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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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*/
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/* Assumption: long double is an intel 80 bit floating point type padded with 6 bytes
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* tu_int is a 64 bit integral type
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* value in long double is representable in tu_int or is negative
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* (no range checking performed)
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*/
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/* gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee |
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* 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm
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*/
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tu_int
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__fixunsxfti(long double a)
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{
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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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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
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