1//===------ Pretty print function for FPBits --------------------*- C++ -*-===//
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#ifndef LLVM_LIBC_SRC___SUPPORT_FPUTIL_FPBITS_STR_H
10#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_FPBITS_STR_H
11
12#include "src/__support/CPP/string.h"
13#include "src/__support/CPP/type_traits.h"
14#include "src/__support/FPUtil/FPBits.h"
15#include "src/__support/integer_to_string.h"
16#include "src/__support/macros/attributes.h"
17
18namespace LIBC_NAMESPACE {
19
20namespace details {
21
22// Format T as uppercase hexadecimal number with leading zeros.
23template <typename T>
24using ZeroPaddedHexFmt = IntegerToString<
25 T, typename radix::Hex::WithWidth<(sizeof(T) * 2)>::WithPrefix::Uppercase>;
26
27} // namespace details
28
29// Converts the bits to a string in the following format:
30// "0x<NNN...N> = S: N, E: 0xNNNN, M:0xNNN...N"
31// 1. N is a hexadecimal digit.
32// 2. The hexadecimal number on the LHS is the raw numerical representation
33// of the bits.
34// 3. The exponent is always 16 bits wide irrespective of the type of the
35// floating encoding.
36template <typename T> LIBC_INLINE cpp::string str(fputil::FPBits<T> x) {
37 using StorageType = typename fputil::FPBits<T>::StorageType;
38
39 if (x.is_nan())
40 return "(NaN)";
41 if (x.is_inf())
42 return x.is_neg() ? "(-Infinity)" : "(+Infinity)";
43
44 const auto sign_char = [](Sign sign) -> char {
45 return sign.is_neg() ? '1' : '0';
46 };
47
48 cpp::string s;
49
50 const details::ZeroPaddedHexFmt<StorageType> bits(x.uintval());
51 s += bits.view();
52
53 s += " = (S: ";
54 s += sign_char(x.sign());
55
56 s += ", E: ";
57 const details::ZeroPaddedHexFmt<uint16_t> exponent(x.get_biased_exponent());
58 s += exponent.view();
59
60 if constexpr (fputil::get_fp_type<T>() == fputil::FPType::X86_Binary80) {
61 s += ", I: ";
62 s += sign_char(x.get_implicit_bit() ? Sign::NEG : Sign::POS);
63 }
64
65 s += ", M: ";
66 const details::ZeroPaddedHexFmt<StorageType> mantissa(x.get_mantissa());
67 s += mantissa.view();
68
69 s += ')';
70 return s;
71}
72
73} // namespace LIBC_NAMESPACE
74
75#endif // LLVM_LIBC_SRC___SUPPORT_FPUTIL_FPBITS_STR_H
76

source code of libc/src/__support/FPUtil/fpbits_str.h