91bd698eaf
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
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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