diff options
Diffstat (limited to 'lib/builtins/ppc/floattitf.c')
| -rw-r--r-- | lib/builtins/ppc/floattitf.c | 46 |
1 files changed, 22 insertions, 24 deletions
diff --git a/lib/builtins/ppc/floattitf.c b/lib/builtins/ppc/floattitf.c index b8e297b6b..6deac6498 100644 --- a/lib/builtins/ppc/floattitf.c +++ b/lib/builtins/ppc/floattitf.c @@ -1,9 +1,8 @@ //===-- lib/builtins/ppc/floattitf.c - Convert int128->long double -*-C -*-===// // -// The LLVM Compiler Infrastructure -// -// This file is dual licensed under the MIT and the University of Illinois Open -// Source Licenses. See LICENSE.TXT for details. +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // @@ -14,35 +13,34 @@ #include <stdint.h> -/* Conversions from signed and unsigned 64-bit int to long double. */ +// Conversions from signed and unsigned 64-bit int to long double. long double __floatditf(int64_t); long double __floatunditf(uint64_t); -/* Convert a signed 128-bit integer to long double. - * This uses the following property: Let hi and lo be 64-bits each, - * and let signed_val_k() and unsigned_val_k() be the value of the - * argument interpreted as a signed or unsigned k-bit integer. Then, - * - * signed_val_128(hi,lo) = signed_val_64(hi) * 2^64 + unsigned_val_64(lo) - * = (long double)hi * 2^64 + (long double)lo, - * - * where (long double)hi and (long double)lo are signed and - * unsigned 64-bit integer to long double conversions, respectively. - */ +// Convert a signed 128-bit integer to long double. +// This uses the following property: Let hi and lo be 64-bits each, +// and let signed_val_k() and unsigned_val_k() be the value of the +// argument interpreted as a signed or unsigned k-bit integer. Then, +// +// signed_val_128(hi,lo) = signed_val_64(hi) * 2^64 + unsigned_val_64(lo) +// = (long double)hi * 2^64 + (long double)lo, +// +// where (long double)hi and (long double)lo are signed and +// unsigned 64-bit integer to long double conversions, respectively. long double __floattitf(__int128_t arg) { - /* Split the int128 argument into 64-bit high and low int64 parts. */ + // Split the int128 argument into 64-bit high and low int64 parts. int64_t ArgHiPart = (int64_t)(arg >> 64); uint64_t ArgLoPart = (uint64_t)arg; - /* Convert each 64-bit part into long double. The high part - * must be a signed conversion and the low part an unsigned conversion - * to ensure the correct result. */ + // Convert each 64-bit part into long double. The high part + // must be a signed conversion and the low part an unsigned conversion + // to ensure the correct result. long double ConvertedHiPart = __floatditf(ArgHiPart); long double ConvertedLoPart = __floatunditf(ArgLoPart); - /* The low bit of ArgHiPart corresponds to the 2^64 bit in arg. - * Multiply the high part by 2^64 to undo the right shift by 64-bits - * done in the splitting. Then, add to the low part to obtain the - * final result. */ + // The low bit of ArgHiPart corresponds to the 2^64 bit in arg. + // Multiply the high part by 2^64 to undo the right shift by 64-bits + // done in the splitting. Then, add to the low part to obtain the + // final result. return ((ConvertedHiPart * 0x1.0p64) + ConvertedLoPart); } |