48 lines
1.4 KiB
C
48 lines
1.4 KiB
C
/* ===-- fixxfti.c - Implement __fixxfti -----------------------------------===
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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 __fixxfti 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 signed long long, rounding toward zero. */
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/* Assumption: long double is an intel 80 bit floating point type padded with 6 bytes
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* su_int is a 32 bit integral type
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* value in long double is representable in ti_int (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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ti_int
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__fixxfti(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)
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return 0;
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ti_int s = -(si_int)((fb.u.high.s.low & 0x00008000) >> 15);
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ti_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 ^ s) - s;
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}
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#endif /* __x86_64 */
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