forked from OSchip/llvm-project
49 lines
1.5 KiB
C
49 lines
1.5 KiB
C
/* ===-- fixxfdi.c - Implement __fixxfdi -----------------------------------===
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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 __fixxfdi for the compiler_rt library.
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*
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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 bytes
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* di_int is a 64 bit integral type
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* value in long double is representable in di_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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COMPILER_RT_ABI di_int
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__fixxfdi(long double a)
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{
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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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#endif /* !_ARCH_PPC */
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