1*0b57cec5SDimitry Andric //===-- floatdixf.c - Implement __floatdixf -------------------------------===// 2*0b57cec5SDimitry Andric // 3*0b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*0b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 5*0b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*0b57cec5SDimitry Andric // 7*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 8*0b57cec5SDimitry Andric // 9*0b57cec5SDimitry Andric // This file implements __floatdixf for the compiler_rt library. 10*0b57cec5SDimitry Andric // 11*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 12*0b57cec5SDimitry Andric 13*0b57cec5SDimitry Andric #if !_ARCH_PPC 14*0b57cec5SDimitry Andric 15*0b57cec5SDimitry Andric #include "int_lib.h" 16*0b57cec5SDimitry Andric 17*0b57cec5SDimitry Andric // Returns: convert a to a long double, rounding toward even. 18*0b57cec5SDimitry Andric 19*0b57cec5SDimitry Andric // Assumption: long double is a IEEE 80 bit floating point type padded to 128 20*0b57cec5SDimitry Andric // bits di_int is a 64 bit integral type 21*0b57cec5SDimitry Andric 22*0b57cec5SDimitry Andric // gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee 23*0b57cec5SDimitry Andric // eeee | 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm 24*0b57cec5SDimitry Andric // mmmm mmmm mmmm 25*0b57cec5SDimitry Andric 26*0b57cec5SDimitry Andric COMPILER_RT_ABI long double __floatdixf(di_int a) { 27*0b57cec5SDimitry Andric if (a == 0) 28*0b57cec5SDimitry Andric return 0.0; 29*0b57cec5SDimitry Andric const unsigned N = sizeof(di_int) * CHAR_BIT; 30*0b57cec5SDimitry Andric const di_int s = a >> (N - 1); 31*0b57cec5SDimitry Andric a = (a ^ s) - s; 32*0b57cec5SDimitry Andric int clz = __builtin_clzll(a); 33*0b57cec5SDimitry Andric int e = (N - 1) - clz; // exponent 34*0b57cec5SDimitry Andric long_double_bits fb; 35*0b57cec5SDimitry Andric fb.u.high.s.low = ((su_int)s & 0x00008000) | // sign 36*0b57cec5SDimitry Andric (e + 16383); // exponent 37*0b57cec5SDimitry Andric fb.u.low.all = a << clz; // mantissa 38*0b57cec5SDimitry Andric return fb.f; 39*0b57cec5SDimitry Andric } 40*0b57cec5SDimitry Andric 41*0b57cec5SDimitry Andric #endif // !_ARCH_PPC 42