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80bit Intel/PPC long double is excluded due to lacking support for the abstraction. Consistently provide saturation logic. Extend to long double on 128bit IEEE extended platforms. Initial patch with test cases from GuanHong Liu. Reviewed by Steve Canon. Differential Revision: http://reviews.llvm.org/D2804 llvm-svn: 231965
51 lines
1.5 KiB
C
51 lines
1.5 KiB
C
/* ===-- fixunsxfti.c - Implement __fixunsxfti -----------------------------===
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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 __fixunsxfti 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 unsigned long long, rounding toward zero.
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* Negative values all become zero.
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*/
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/* Assumption: long double is an intel 80 bit floating point type padded with 6 bytes
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* tu_int is a 128 bit integral type
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* value in long double is representable in tu_int or is negative
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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 tu_int
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__fixunsxfti(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 || (fb.u.high.s.low & 0x00008000))
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return 0;
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if ((unsigned)e > sizeof(tu_int) * CHAR_BIT)
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return ~(tu_int)0;
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tu_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;
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}
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#endif /* CRT_HAS_128BIT */
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