1249259Sdim/* ===-- floatdixf.c - Implement __floatdixf -------------------------------=== 2249259Sdim * 3249259Sdim * The LLVM Compiler Infrastructure 4249259Sdim * 5249259Sdim * This file is dual licensed under the MIT and the University of Illinois Open 6249259Sdim * Source Licenses. See LICENSE.TXT for details. 7249259Sdim * 8249259Sdim * ===----------------------------------------------------------------------=== 9249259Sdim * 10249259Sdim * This file implements __floatdixf for the compiler_rt library. 11249259Sdim * 12249259Sdim * ===----------------------------------------------------------------------=== 13249259Sdim */ 14280031Sdim 15249259Sdim#if !_ARCH_PPC 16249259Sdim 17249259Sdim#include "int_lib.h" 18249259Sdim 19251662Sdim/* Returns: convert a to a long double, rounding toward even. */ 20249259Sdim 21261991Sdim/* Assumption: long double is a IEEE 80 bit floating point type padded to 128 bits 22261991Sdim * di_int is a 64 bit integral type 23249259Sdim */ 24249259Sdim 25249259Sdim/* gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee | 26249259Sdim * 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm 27276479Sdim */ 28276479Sdim 29249259SdimCOMPILER_RT_ABI long double 30249259Sdim__floatdixf(di_int a) 31249259Sdim{ 32249259Sdim if (a == 0) 33261991Sdim return 0.0; 34261991Sdim const unsigned N = sizeof(di_int) * CHAR_BIT; 35261991Sdim const di_int s = a >> (N-1); 36261991Sdim a = (a ^ s) - s; 37261991Sdim int clz = __builtin_clzll(a); 38280031Sdim int e = (N - 1) - clz ; /* exponent */ 39276479Sdim long_double_bits fb; 40276479Sdim fb.u.high.s.low = ((su_int)s & 0x00008000) | /* sign */ 41249259Sdim (e + 16383); /* exponent */ 42261991Sdim fb.u.low.all = a << clz; /* mantissa */ 43251662Sdim return fb.f; 44276479Sdim} 45261991Sdim 46251662Sdim#endif /* !_ARCH_PPC */ 47276479Sdim