41 lines
1.2 KiB
C
41 lines
1.2 KiB
C
//===-- floatundixf.c - Implement __floatundixf ---------------------------===//
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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 __floatundixf for the compiler_rt library.
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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 long double, rounding toward even.
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// Assumption: long double is a IEEE 80 bit floating point type padded to 128 bits
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// du_int is a 64 bit integral type
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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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long double
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__floatundixf(du_int a)
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{
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if (a == 0)
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return 0.0;
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const unsigned N = sizeof(du_int) * CHAR_BIT;
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int clz = __builtin_clzll(a);
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int e = (N - 1) - clz ; // exponent
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long_double_bits fb;
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fb.u.high.low = (e + 16383); // exponent
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fb.u.low.all = a << clz; // mantissa
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return fb.f;
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}
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#endif
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