48 lines
1.3 KiB
C
48 lines
1.3 KiB
C
/* ===-- fixunsdfti.c - Implement __fixunsdfti -----------------------------===
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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 __fixunsdfti 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: double is a IEEE 64 bit floating point type
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* tu_int is a 64 bit integral type
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* value in 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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/* seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm */
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tu_int
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__fixunsdfti(double a)
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{
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double_bits fb;
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fb.f = a;
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int e = ((fb.u.s.high & 0x7FF00000) >> 20) - 1023;
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if (e < 0 || (fb.u.s.high & 0x80000000))
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return 0;
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tu_int r = 0x0010000000000000uLL | (fb.u.all & 0x000FFFFFFFFFFFFFuLL);
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if (e > 52)
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r <<= (e - 52);
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else
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r >>= (52 - e);
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return r;
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}
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#endif
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