PGO: Add explicit static initialization
Instead of relying on explicit static initialization from translation
units, create a new file, InstrProfilingRuntime.cc, with an
__llvm_pgo_runtime variable. After this commit (and its pair in clang),
the driver will create a use of this variable. Unless the user defines
their own version, the new object file will get pulled in, including
that C++ static initialization that calls
__llvm_pgo_register_write_atexit.
The result is that, at least on Darwin, static initialization typically
consists of a single function call, which registers a writeout functino
atexit. Furthermore, users can skip even this behaviour by defining
their own __llvm_pgo_runtime.
<rdar://problem/15943240>
llvm-svn: 204380
2014-03-21 03:23:53 +08:00
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//===- InstrProfilingRuntime.cpp - PGO runtime initialization -------------===//
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//
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2019-01-19 16:50:56 +08:00
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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PGO: Add explicit static initialization
Instead of relying on explicit static initialization from translation
units, create a new file, InstrProfilingRuntime.cc, with an
__llvm_pgo_runtime variable. After this commit (and its pair in clang),
the driver will create a use of this variable. Unless the user defines
their own version, the new object file will get pulled in, including
that C++ static initialization that calls
__llvm_pgo_register_write_atexit.
The result is that, at least on Darwin, static initialization typically
consists of a single function call, which registers a writeout functino
atexit. Furthermore, users can skip even this behaviour by defining
their own __llvm_pgo_runtime.
<rdar://problem/15943240>
llvm-svn: 204380
2014-03-21 03:23:53 +08:00
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//
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//===----------------------------------------------------------------------===//
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extern "C" {
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2014-03-22 02:29:15 +08:00
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#include "InstrProfiling.h"
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PGO: Add explicit static initialization
Instead of relying on explicit static initialization from translation
units, create a new file, InstrProfilingRuntime.cc, with an
__llvm_pgo_runtime variable. After this commit (and its pair in clang),
the driver will create a use of this variable. Unless the user defines
their own version, the new object file will get pulled in, including
that C++ static initialization that calls
__llvm_pgo_register_write_atexit.
The result is that, at least on Darwin, static initialization typically
consists of a single function call, which registers a writeout functino
atexit. Furthermore, users can skip even this behaviour by defining
their own __llvm_pgo_runtime.
<rdar://problem/15943240>
llvm-svn: 204380
2014-03-21 03:23:53 +08:00
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2016-07-22 12:08:16 +08:00
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/* int __llvm_profile_runtime */
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COMPILER_RT_VISIBILITY int INSTR_PROF_PROFILE_RUNTIME_VAR;
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PGO: Add explicit static initialization
Instead of relying on explicit static initialization from translation
units, create a new file, InstrProfilingRuntime.cc, with an
__llvm_pgo_runtime variable. After this commit (and its pair in clang),
the driver will create a use of this variable. Unless the user defines
their own version, the new object file will get pulled in, including
that C++ static initialization that calls
__llvm_pgo_register_write_atexit.
The result is that, at least on Darwin, static initialization typically
consists of a single function call, which registers a writeout functino
atexit. Furthermore, users can skip even this behaviour by defining
their own __llvm_pgo_runtime.
<rdar://problem/15943240>
llvm-svn: 204380
2014-03-21 03:23:53 +08:00
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}
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namespace {
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2014-05-16 09:30:24 +08:00
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class RegisterRuntime {
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PGO: Add explicit static initialization
Instead of relying on explicit static initialization from translation
units, create a new file, InstrProfilingRuntime.cc, with an
__llvm_pgo_runtime variable. After this commit (and its pair in clang),
the driver will create a use of this variable. Unless the user defines
their own version, the new object file will get pulled in, including
that C++ static initialization that calls
__llvm_pgo_register_write_atexit.
The result is that, at least on Darwin, static initialization typically
consists of a single function call, which registers a writeout functino
atexit. Furthermore, users can skip even this behaviour by defining
their own __llvm_pgo_runtime.
<rdar://problem/15943240>
llvm-svn: 204380
2014-03-21 03:23:53 +08:00
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public:
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2014-05-16 09:30:24 +08:00
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RegisterRuntime() {
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2020-03-22 07:41:00 +08:00
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__llvm_profile_initialize();
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2014-05-16 09:30:24 +08:00
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}
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PGO: Add explicit static initialization
Instead of relying on explicit static initialization from translation
units, create a new file, InstrProfilingRuntime.cc, with an
__llvm_pgo_runtime variable. After this commit (and its pair in clang),
the driver will create a use of this variable. Unless the user defines
their own version, the new object file will get pulled in, including
that C++ static initialization that calls
__llvm_pgo_register_write_atexit.
The result is that, at least on Darwin, static initialization typically
consists of a single function call, which registers a writeout functino
atexit. Furthermore, users can skip even this behaviour by defining
their own __llvm_pgo_runtime.
<rdar://problem/15943240>
llvm-svn: 204380
2014-03-21 03:23:53 +08:00
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};
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2014-05-16 09:30:24 +08:00
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RegisterRuntime Registration;
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PGO: Add explicit static initialization
Instead of relying on explicit static initialization from translation
units, create a new file, InstrProfilingRuntime.cc, with an
__llvm_pgo_runtime variable. After this commit (and its pair in clang),
the driver will create a use of this variable. Unless the user defines
their own version, the new object file will get pulled in, including
that C++ static initialization that calls
__llvm_pgo_register_write_atexit.
The result is that, at least on Darwin, static initialization typically
consists of a single function call, which registers a writeout functino
atexit. Furthermore, users can skip even this behaviour by defining
their own __llvm_pgo_runtime.
<rdar://problem/15943240>
llvm-svn: 204380
2014-03-21 03:23:53 +08:00
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}
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