1*3cab2bb3Spatrick //===-- floatdixf.c - Implement __floatdixf -------------------------------===// 2*3cab2bb3Spatrick // 3*3cab2bb3Spatrick // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*3cab2bb3Spatrick // See https://llvm.org/LICENSE.txt for license information. 5*3cab2bb3Spatrick // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*3cab2bb3Spatrick // 7*3cab2bb3Spatrick //===----------------------------------------------------------------------===// 8*3cab2bb3Spatrick // 9*3cab2bb3Spatrick // This file implements __floatdixf for the compiler_rt library. 10*3cab2bb3Spatrick // 11*3cab2bb3Spatrick //===----------------------------------------------------------------------===// 12*3cab2bb3Spatrick 13*3cab2bb3Spatrick #if !_ARCH_PPC 14*3cab2bb3Spatrick 15*3cab2bb3Spatrick #include "int_lib.h" 16*3cab2bb3Spatrick 17*3cab2bb3Spatrick // Returns: convert a to a long double, rounding toward even. 18*3cab2bb3Spatrick 19*3cab2bb3Spatrick // Assumption: long double is a IEEE 80 bit floating point type padded to 128 20*3cab2bb3Spatrick // bits di_int is a 64 bit integral type 21*3cab2bb3Spatrick 22*3cab2bb3Spatrick // gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee 23*3cab2bb3Spatrick // eeee | 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm 24*3cab2bb3Spatrick // mmmm mmmm mmmm 25*3cab2bb3Spatrick __floatdixf(di_int a)26*3cab2bb3SpatrickCOMPILER_RT_ABI long double __floatdixf(di_int a) { 27*3cab2bb3Spatrick if (a == 0) 28*3cab2bb3Spatrick return 0.0; 29*3cab2bb3Spatrick const unsigned N = sizeof(di_int) * CHAR_BIT; 30*3cab2bb3Spatrick const di_int s = a >> (N - 1); 31*3cab2bb3Spatrick a = (a ^ s) - s; 32*3cab2bb3Spatrick int clz = __builtin_clzll(a); 33*3cab2bb3Spatrick int e = (N - 1) - clz; // exponent 34*3cab2bb3Spatrick long_double_bits fb; 35*3cab2bb3Spatrick fb.u.high.s.low = ((su_int)s & 0x00008000) | // sign 36*3cab2bb3Spatrick (e + 16383); // exponent 37*3cab2bb3Spatrick fb.u.low.all = a << clz; // mantissa 38*3cab2bb3Spatrick return fb.f; 39*3cab2bb3Spatrick } 40*3cab2bb3Spatrick 41*3cab2bb3Spatrick #endif // !_ARCH_PPC 42