1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
|
# This file is licensed 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
"""LLVM libc starlark rules for building individual functions."""
load(":platforms.bzl", "PLATFORM_CPU_ARM64", "PLATFORM_CPU_X86_64")
load("@bazel_skylib//lib:selects.bzl", "selects")
LIBC_ROOT_TARGET = ":libc_root"
INTERNAL_SUFFIX = ".__internal__"
def _libc_library(name, copts = None, **kwargs):
"""Internal macro to serve as a base for all other libc library rules.
Args:
name: Target name.
copts: The special compiler options for the target.
**kwargs: All other attributes relevant for the cc_library rule.
"""
copts = copts or []
# We want all libc sources to be compiled with "hidden" visibility.
# The public symbols will be given "default" visibility explicitly.
# See src/__support/common.h for more information.
copts = copts + ["-fvisibility=hidden"]
native.cc_library(
name = name,
copts = copts,
linkstatic = 1,
**kwargs
)
# A convenience var which should be used to list all libc support libraries.
# Any library which does not define a public function should be listed with
# libc_support_library.
libc_support_library = _libc_library
def libc_function(
name,
srcs,
weak = False,
deps = None,
copts = None,
local_defines = None,
**kwargs):
"""Add target for a libc function.
The libc function is eventually available as a cc_library target by name
"name". LLVM libc implementations of libc functions are in C++. So, this
rule internally generates a C wrapper for the C++ implementation and adds
it to the source list of the cc_library. This way, the C++ implementation
and the C wrapper are both available in the cc_library.
Args:
name: Target name. It is normally the name of the function this target is
for.
srcs: The .cpp files which contain the function implementation.
weak: Make the symbol corresponding to the libc function "weak".
deps: The list of target dependencies if any.
copts: The list of options to add to the C++ compilation command.
local_defines: The preprocessor defines which will be prepended with -D
and passed to the compile command of this target but not
its deps.
**kwargs: Other attributes relevant for a cc_library. For example, deps.
"""
deps = deps or []
# We use the explicit equals pattern here because append and += mutate the
# original list, where this creates a new list and stores it in deps.
deps = deps + [LIBC_ROOT_TARGET]
copts = copts or []
copts = copts + ["-O3", "-fno-builtin", "-fno-lax-vector-conversions"]
# We compile the code twice, the first target is suffixed with ".__internal__" and contains the
# C++ functions in the "__llvm_libc" namespace. This allows us to test the function in the
# presence of another libc.
native.cc_library(
name = name + INTERNAL_SUFFIX,
srcs = srcs,
deps = deps,
copts = copts,
linkstatic = 1,
**kwargs
)
# This second target is the llvm libc C function.
func_attrs = ["__attribute__((visibility(\"default\")))"]
if weak:
func_attrs = func_attrs + ["__attribute__((weak))"]
local_defines = local_defines or ["LIBC_COPT_PUBLIC_PACKAGING"]
local_defines = local_defines + ["LLVM_LIBC_FUNCTION_ATTR='%s'" % " ".join(func_attrs)]
_libc_library(
name = name,
srcs = srcs,
deps = deps,
copts = copts,
local_defines = local_defines,
**kwargs
)
def libc_math_function(
name,
specializations = None,
additional_deps = None):
"""Add a target for a math function.
Args:
name: The name of the function.
specializations: List of machine specializations available for this
function. Possible specializations are "generic",
"aarch64" and "x86_64".
additional_deps: Other deps like helper cc_library targes used by the
math function.
"""
additional_deps = additional_deps or []
specializations = specializations or ["generic"]
select_map = {}
if "generic" in specializations:
select_map["//conditions:default"] = ["src/math/generic/" + name + ".cpp"]
if "aarch64" in specializations:
select_map[PLATFORM_CPU_ARM64] = ["src/math/aarch64/" + name + ".cpp"]
if "x86_64" in specializations:
select_map[PLATFORM_CPU_X86_64] = ["src/math/x86_64/" + name + ".cpp"]
#TODO(michaelrj): Fix the floating point dependencies
OLD_FPUTIL_DEPS = [
":__support_fputil_basic_operations",
":__support_fputil_division_and_remainder_operations",
":__support_fputil_fenv_impl",
":__support_fputil_fp_bits",
":__support_fputil_float_properties",
":__support_fputil_hypot",
":__support_fputil_manipulation_functions",
":__support_fputil_nearest_integer_operations",
":__support_fputil_normal_float",
":__support_fputil_platform_defs",
":__support_builtin_wrappers",
":__support_fputil_except_value_utils",
]
libc_function(
name = name,
srcs = selects.with_or(select_map),
hdrs = ["src/math/" + name + ".h"],
deps = [":__support_common"] + OLD_FPUTIL_DEPS + additional_deps,
)
|
