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/* ===-- 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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#ifdef CRT_HAS_128BIT |
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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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* ti_int is a 128 bit integral type |
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* value in long double is representable in ti_int |
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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 ti_int |
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__fixxfti(long double a) |
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{ |
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const ti_int ti_max = (ti_int)((~(tu_int)0) / 2); |
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const ti_int ti_min = -ti_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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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 ((unsigned)e >= sizeof(ti_int) * CHAR_BIT) |
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return a > 0 ? ti_max : ti_min; |
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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 /* CRT_HAS_128BIT */ |