1*7c3d14c8STreehugger Robot /* ===-- floatdixf.c - Implement __floatdixf -------------------------------=== 2*7c3d14c8STreehugger Robot * 3*7c3d14c8STreehugger Robot * The LLVM Compiler Infrastructure 4*7c3d14c8STreehugger Robot * 5*7c3d14c8STreehugger Robot * This file is dual licensed under the MIT and the University of Illinois Open 6*7c3d14c8STreehugger Robot * Source Licenses. See LICENSE.TXT for details. 7*7c3d14c8STreehugger Robot * 8*7c3d14c8STreehugger Robot * ===----------------------------------------------------------------------=== 9*7c3d14c8STreehugger Robot * 10*7c3d14c8STreehugger Robot * This file implements __floatdixf for the compiler_rt library. 11*7c3d14c8STreehugger Robot * 12*7c3d14c8STreehugger Robot * ===----------------------------------------------------------------------=== 13*7c3d14c8STreehugger Robot */ 14*7c3d14c8STreehugger Robot 15*7c3d14c8STreehugger Robot #if !_ARCH_PPC 16*7c3d14c8STreehugger Robot 17*7c3d14c8STreehugger Robot #include "int_lib.h" 18*7c3d14c8STreehugger Robot 19*7c3d14c8STreehugger Robot /* Returns: convert a to a long double, rounding toward even. */ 20*7c3d14c8STreehugger Robot 21*7c3d14c8STreehugger Robot /* Assumption: long double is a IEEE 80 bit floating point type padded to 128 bits 22*7c3d14c8STreehugger Robot * di_int is a 64 bit integral type 23*7c3d14c8STreehugger Robot */ 24*7c3d14c8STreehugger Robot 25*7c3d14c8STreehugger Robot /* gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee | 26*7c3d14c8STreehugger Robot * 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm 27*7c3d14c8STreehugger Robot */ 28*7c3d14c8STreehugger Robot 29*7c3d14c8STreehugger Robot COMPILER_RT_ABI long double __floatdixf(di_int a)30*7c3d14c8STreehugger Robot__floatdixf(di_int a) 31*7c3d14c8STreehugger Robot { 32*7c3d14c8STreehugger Robot if (a == 0) 33*7c3d14c8STreehugger Robot return 0.0; 34*7c3d14c8STreehugger Robot const unsigned N = sizeof(di_int) * CHAR_BIT; 35*7c3d14c8STreehugger Robot const di_int s = a >> (N-1); 36*7c3d14c8STreehugger Robot a = (a ^ s) - s; 37*7c3d14c8STreehugger Robot int clz = __builtin_clzll(a); 38*7c3d14c8STreehugger Robot int e = (N - 1) - clz ; /* exponent */ 39*7c3d14c8STreehugger Robot long_double_bits fb; 40*7c3d14c8STreehugger Robot fb.u.high.s.low = ((su_int)s & 0x00008000) | /* sign */ 41*7c3d14c8STreehugger Robot (e + 16383); /* exponent */ 42*7c3d14c8STreehugger Robot fb.u.low.all = a << clz; /* mantissa */ 43*7c3d14c8STreehugger Robot return fb.f; 44*7c3d14c8STreehugger Robot } 45*7c3d14c8STreehugger Robot 46*7c3d14c8STreehugger Robot #endif /* !_ARCH_PPC */ 47