177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao/* ===-- floatdixf.c - Implement __floatdixf -------------------------------=== 277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * 377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * The LLVM Compiler Infrastructure 477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * 577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * This file is distributed under the University of Illinois Open Source 677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * License. See LICENSE.TXT for details. 777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * 877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * ===----------------------------------------------------------------------=== 977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * 1077ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * This file implements __floatdixf for the compiler_rt library. 1177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * 1277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * ===----------------------------------------------------------------------=== 1377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao */ 1477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 1577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao#if !_ARCH_PPC 1677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 1777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao#include "int_lib.h" 1877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 1977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao/* Returns: convert a to a long double, rounding toward even. */ 2077ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 2177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao/* Assumption: long double is a IEEE 80 bit floating point type padded to 128 bits 2277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * di_int is a 64 bit integral type 2377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao */ 2477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 2577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao/* gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee | 2677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm 2777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao */ 2877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 2977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liaolong double 3077ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao__floatdixf(di_int a) 3177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao{ 3277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao if (a == 0) 3377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao return 0.0; 3477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao const unsigned N = sizeof(di_int) * CHAR_BIT; 3577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao const di_int s = a >> (N-1); 3677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao a = (a ^ s) - s; 3777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao int clz = __builtin_clzll(a); 3877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao int e = (N - 1) - clz ; /* exponent */ 3977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao long_double_bits fb; 4077ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao fb.u.high.s.low = ((su_int)s & 0x00008000) | /* sign */ 4177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao (e + 16383); /* exponent */ 4277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao fb.u.low.all = a << clz; /* mantissa */ 4377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao return fb.f; 4477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao} 4577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 4677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao#endif /* !_ARCH_PPC */ 47