forked from OSchip/llvm-project
44 lines
1.2 KiB
C
44 lines
1.2 KiB
C
//===-- fixdfti.c - Implement __fixdfti -----------------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements __fixdfti for the compiler_rt library.
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//
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//===----------------------------------------------------------------------===//
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#if __x86_64
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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: double is a IEEE 64 bit floating point type
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// su_int is a 32 bit integral type
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// value in double is representable in ti_int (no range checking performed)
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// seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm
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ti_int
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__fixdfti(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.high & 0x7FF00000) >> 20) - 1023;
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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 & 0x80000000) >> 31;
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ti_int r = 0x0010000000000000uLL | (0x000FFFFFFFFFFFFFuLL & fb.u.all);
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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 ^ s) - s;
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}
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#endif
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