1 //===-- Basic operations on floating point numbers --------------*- 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_UTILS_FPUTIL_BASIC_OPERATIONS_H
10 #define LLVM_LIBC_UTILS_FPUTIL_BASIC_OPERATIONS_H
11
12 #include "FPBits.h"
13
14 #include "utils/CPP/TypeTraits.h"
15
16 namespace __llvm_libc {
17 namespace fputil {
18
19 template <typename T,
20 cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
abs(T x)21 static inline T abs(T x) {
22 FPBits<T> bits(x);
23 bits.sign = 0;
24 return T(bits);
25 }
26
27 template <typename T,
28 cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
fmin(T x,T y)29 static inline T fmin(T x, T y) {
30 FPBits<T> bitx(x), bity(y);
31
32 if (bitx.isNaN()) {
33 return y;
34 } else if (bity.isNaN()) {
35 return x;
36 } else if (bitx.sign != bity.sign) {
37 // To make sure that fmin(+0, -0) == -0 == fmin(-0, +0), whenever x and
38 // y has different signs and both are not NaNs, we return the number
39 // with negative sign.
40 return (bitx.sign ? x : y);
41 } else {
42 return (x < y ? x : y);
43 }
44 }
45
46 template <typename T,
47 cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
fmax(T x,T y)48 static inline T fmax(T x, T y) {
49 FPBits<T> bitx(x), bity(y);
50
51 if (bitx.isNaN()) {
52 return y;
53 } else if (bity.isNaN()) {
54 return x;
55 } else if (bitx.sign != bity.sign) {
56 // To make sure that fmax(+0, -0) == +0 == fmax(-0, +0), whenever x and
57 // y has different signs and both are not NaNs, we return the number
58 // with positive sign.
59 return (bitx.sign ? y : x);
60 } else {
61 return (x > y ? x : y);
62 }
63 }
64
65 template <typename T,
66 cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
fdim(T x,T y)67 static inline T fdim(T x, T y) {
68 FPBits<T> bitx(x), bity(y);
69
70 if (bitx.isNaN()) {
71 return x;
72 }
73
74 if (bity.isNaN()) {
75 return y;
76 }
77
78 return (x > y ? x - y : 0);
79 }
80
81 } // namespace fputil
82 } // namespace __llvm_libc
83
84 #endif // LLVM_LIBC_UTILS_FPUTIL_BASIC_OPERATIONS_H
85