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/* ===-- floatdixf.c - Implement __floatdixf -------------------------------=== |
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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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* This file implements __floatdixf 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 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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* di_int is a 64 bit integral type |
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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 long double |
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__floatdixf(di_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(di_int) * CHAR_BIT; |
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const di_int s = a >> (N-1); |
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a = (a ^ s) - s; |
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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.s.low = ((su_int)s & 0x00008000) | /* sign */ |
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(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 /* !_ARCH_PPC */ |