1 //===-- floatdidf.c - Implement __floatdidf -------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements __floatdidf for the compiler_rt library. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "int_lib.h" 14 15 // Returns: convert a to a double, rounding toward even. 16 17 // Assumption: double is a IEEE 64 bit floating point type 18 // di_int is a 64 bit integral type 19 20 // seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm 21 // mmmm 22 23 #ifndef __SOFTFP__ 24 // Support for systems that have hardware floating-point; we'll set the inexact 25 // flag as a side-effect of this computation. 26 27 COMPILER_RT_ABI double __floatdidf(di_int a) { 28 static const double twop52 = 4503599627370496.0; // 0x1.0p52 29 static const double twop32 = 4294967296.0; // 0x1.0p32 30 31 union { 32 int64_t x; 33 double d; 34 } low = {.d = twop52}; 35 36 const double high = (int32_t)(a >> 32) * twop32; 37 low.x |= a & INT64_C(0x00000000ffffffff); 38 39 const double result = (high - twop52) + low.d; 40 return result; 41 } 42 43 #else 44 // Support for systems that don't have hardware floating-point; there are no 45 // flags to set, and we don't want to code-gen to an unknown soft-float 46 // implementation. 47 48 #define SRC_I64 49 #define DST_DOUBLE 50 #include "int_to_fp_impl.inc" 51 52 COMPILER_RT_ABI double __floatdidf(di_int a) { return __floatXiYf__(a); } 53 #endif 54 55 #if defined(__ARM_EABI__) 56 #if defined(COMPILER_RT_ARMHF_TARGET) 57 AEABI_RTABI double __aeabi_l2d(di_int a) { return __floatdidf(a); } 58 #else 59 COMPILER_RT_ALIAS(__floatdidf, __aeabi_l2d) 60 #endif 61 #endif 62 63 #if defined(__MINGW32__) && defined(__arm__) 64 COMPILER_RT_ALIAS(__floatdidf, __i64tod) 65 #endif 66