1//===-- Portable optimization macros ----------------------------*- 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// This header file defines portable macros for performance optimization.
9
10#ifndef LLVM_LIBC_SRC___SUPPORT_MACROS_OPTIMIZATION_H
11#define LLVM_LIBC_SRC___SUPPORT_MACROS_OPTIMIZATION_H
12
13#include "src/__support/macros/attributes.h" // LIBC_INLINE
14#include "src/__support/macros/config.h"
15#include "src/__support/macros/properties/compiler.h" // LIBC_COMPILER_IS_CLANG
16
17// We use a template to implement likely/unlikely to make sure that we don't
18// accidentally pass an integer.
19namespace LIBC_NAMESPACE_DECL {
20namespace details {
21template <typename T>
22LIBC_INLINE constexpr bool expects_bool_condition(T value, T expected) {
23 return __builtin_expect(value, expected);
24}
25} // namespace details
26} // namespace LIBC_NAMESPACE_DECL
27#define LIBC_LIKELY(x) LIBC_NAMESPACE::details::expects_bool_condition(x, true)
28#define LIBC_UNLIKELY(x) \
29 LIBC_NAMESPACE::details::expects_bool_condition(x, false)
30
31#if defined(LIBC_COMPILER_IS_CLANG)
32#define LIBC_LOOP_NOUNROLL _Pragma("nounroll")
33#define LIBC_LOOP_UNROLL _Pragma("unroll")
34#elif defined(LIBC_COMPILER_IS_GCC)
35#define LIBC_LOOP_NOUNROLL _Pragma("GCC unroll 0")
36#define LIBC_LOOP_UNROLL _Pragma("GCC unroll 2048")
37#else
38#error "Unhandled compiler"
39#endif
40
41// Defining optimization options for math functions.
42// TODO: Exporting this to public generated headers?
43#define LIBC_MATH_SKIP_ACCURATE_PASS 0x01
44#define LIBC_MATH_SMALL_TABLES 0x02
45#define LIBC_MATH_NO_ERRNO 0x04
46#define LIBC_MATH_NO_EXCEPT 0x08
47#define LIBC_MATH_FAST \
48 (LIBC_MATH_SKIP_ACCURATE_PASS | LIBC_MATH_SMALL_TABLES | \
49 LIBC_MATH_NO_ERRNO | LIBC_MATH_NO_EXCEPT)
50#define LIBC_MATH_INTERMEDIATE_COMP_IN_FLOAT 0x10
51
52#ifndef LIBC_MATH
53#define LIBC_MATH 0
54#endif // LIBC_MATH
55
56#if (LIBC_MATH & LIBC_MATH_SKIP_ACCURATE_PASS)
57#define LIBC_MATH_HAS_SKIP_ACCURATE_PASS
58#endif
59
60#if (LIBC_MATH & LIBC_MATH_SMALL_TABLES)
61#define LIBC_MATH_HAS_SMALL_TABLES
62#endif
63
64#if (LIBC_MATH & LIBC_MATH_INTERMEDIATE_COMP_IN_FLOAT)
65#define LIBC_MATH_HAS_INTERMEDIATE_COMP_IN_FLOAT
66#endif
67
68#if (LIBC_MATH & LIBC_MATH_NO_ERRNO)
69#define LIBC_MATH_HAS_NO_ERRNO
70#endif
71
72#if (LIBC_MATH & LIBC_MATH_NO_EXCEPT)
73#define LIBC_MATH_HAS_NO_EXCEPT
74#endif
75
76#endif // LLVM_LIBC_SRC___SUPPORT_MACROS_OPTIMIZATION_H
77