[PGO] Exposing PGO's Counter Reset and File Dumping APIs #76471

qiongsiwu · 2023-12-27T21:14:29Z

This PR exposes four PGO functions

__llvm_profile_set_filename
__llvm_profile_reset_counters,
__llvm_profile_dump
__llvm_orderfile_dump

to user programs through the new header instr_prof_interface.h under compiler-rt/include/profile. This way, the user can include the header profile/instr_prof_interface.h to introduce these four names to their programs.

Additionally, this PR defines macro __LLVM_INSTR_PROFILE_GENERATE when the program is compiled with profile generation, and defines macro __LLVM_INSTR_PROFILE_USE when the program is compiled with profile use. __LLVM_INSTR_PROFILE_GENERATE together with instr_prof_interface.h define the PGO functions only when the program is compiled with profile generation. When profile generation is off, these PGO functions are defined away and leave no trace in the user's program.

Background: https://discourse.llvm.org/t/pgo-are-the-llvm-profile-functions-stable-c-apis-across-llvm-releases/75832

llvmbot · 2023-12-27T21:14:56Z

@llvm/pr-subscribers-pgo
@llvm/pr-subscribers-clang-tidy

@llvm/pr-subscribers-clang

Author: Qiongsi Wu (qiongsiwu)

Changes

This PR exposes three PGO functions __llvm_profile_reset_counters, __llvm_profile_dump and __llvm_orderfile_dump to user programs through the new header instr_prof_interface.h under compiler-rt/include/profile. This way, the user can include the header profile/instr_prof_interface.h to introduce these three names to their programs.

Additionally, this PR defines macro __LLVM_INSTR_PROFILE_GENERATE when the program is compiled with profile generation, and defines macro __LLVM_INSTR_PROFILE_USE when the program is compiled with profile use. __LLVM_INSTR_PROFILE_GENERATE together with instr_prof_interface.h define the three PGO functions only when the program is compiled with profile generation. When profile generation is off, these PGO functions are defined away and leave no trace in the user's program.

Full diff: https://github.com/llvm/llvm-project/pull/76471.diff

10 Files Affected:

(modified) clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.cpp (+1-1)
(modified) clang/include/clang/Basic/CodeGenOptions.h (+6)
(modified) clang/include/clang/Frontend/Utils.h (+3-1)
(modified) clang/lib/Frontend/CompilerInstance.cpp (+1-1)
(modified) clang/lib/Frontend/InitPreprocessor.cpp (+19-4)
(modified) clang/test/Profile/c-general.c (+9)
(modified) compiler-rt/include/CMakeLists.txt (+1)
(added) compiler-rt/include/profile/instr_prof_interface.h (+66)
(modified) compiler-rt/lib/profile/InstrProfiling.h (+3-29)
(added) compiler-rt/test/profile/instrprof-api.c (+26)

diff --git a/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.cpp b/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.cpp
index e414ac8c770508..5ecd4fb19131e4 100644
--- a/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.cpp
+++ b/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.cpp
@@ -100,7 +100,7 @@ ExpandModularHeadersPPCallbacks::ExpandModularHeadersPPCallbacks(
                                               /*OwnsHeaderSearch=*/false);
   PP->Initialize(Compiler.getTarget(), Compiler.getAuxTarget());
   InitializePreprocessor(*PP, *PO, Compiler.getPCHContainerReader(),
-                         Compiler.getFrontendOpts());
+                         Compiler.getFrontendOpts(), Compiler.getCodeGenOpts());
   ApplyHeaderSearchOptions(*HeaderInfo, *HSO, LangOpts,
                            Compiler.getTarget().getTriple());
 }
diff --git a/clang/include/clang/Basic/CodeGenOptions.h b/clang/include/clang/Basic/CodeGenOptions.h
index 6952b48e898a81..e06f1094784caf 100644
--- a/clang/include/clang/Basic/CodeGenOptions.h
+++ b/clang/include/clang/Basic/CodeGenOptions.h
@@ -494,6 +494,12 @@ class CodeGenOptions : public CodeGenOptionsBase {
     return getProfileInstr() == ProfileCSIRInstr;
   }
 
+  /// Check if any form of instrumentation is on.
+  bool hasProfileInstr() const {
+    return hasProfileClangInstr() || hasProfileIRInstr() ||
+           hasProfileCSIRInstr();
+  }
+
   /// Check if Clang profile use is on.
   bool hasProfileClangUse() const {
     return getProfileUse() == ProfileClangInstr;
diff --git a/clang/include/clang/Frontend/Utils.h b/clang/include/clang/Frontend/Utils.h
index 143cf4359f00b5..604e42067a3f1e 100644
--- a/clang/include/clang/Frontend/Utils.h
+++ b/clang/include/clang/Frontend/Utils.h
@@ -43,12 +43,14 @@ class PCHContainerReader;
 class Preprocessor;
 class PreprocessorOptions;
 class PreprocessorOutputOptions;
+class CodeGenOptions;
 
 /// InitializePreprocessor - Initialize the preprocessor getting it and the
 /// environment ready to process a single file.
 void InitializePreprocessor(Preprocessor &PP, const PreprocessorOptions &PPOpts,
                             const PCHContainerReader &PCHContainerRdr,
-                            const FrontendOptions &FEOpts);
+                            const FrontendOptions &FEOpts,
+                            const CodeGenOptions &CodeGenOpts);
 
 /// DoPrintPreprocessedInput - Implement -E mode.
 void DoPrintPreprocessedInput(Preprocessor &PP, raw_ostream *OS,
diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 56bbef9697b650..ea44a26b6db7da 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -470,7 +470,7 @@ void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
 
   // Predefine macros and configure the preprocessor.
   InitializePreprocessor(*PP, PPOpts, getPCHContainerReader(),
-                         getFrontendOpts());
+                         getFrontendOpts(), getCodeGenOpts());
 
   // Initialize the header search object.  In CUDA compilations, we use the aux
   // triple (the host triple) to initialize our header search, since we need to
diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
index d83128adb511ef..fe0fd3614113c4 100644
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -1364,12 +1364,22 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
   TI.getTargetDefines(LangOpts, Builder);
 }
 
+static void InitializePGOProfileMacros(const CodeGenOptions &CodeGenOpts,
+                                       MacroBuilder &Builder) {
+  if (CodeGenOpts.hasProfileInstr())
+    Builder.defineMacro("__LLVM_INSTR_PROFILE_GENERATE");
+
+  if (CodeGenOpts.hasProfileIRUse() || CodeGenOpts.hasProfileClangUse())
+    Builder.defineMacro("__LLVM_INSTR_PROFILE_USE");
+}
+
 /// InitializePreprocessor - Initialize the preprocessor getting it and the
 /// environment ready to process a single file.
-void clang::InitializePreprocessor(
-    Preprocessor &PP, const PreprocessorOptions &InitOpts,
-    const PCHContainerReader &PCHContainerRdr,
-    const FrontendOptions &FEOpts) {
+void clang::InitializePreprocessor(Preprocessor &PP,
+                                   const PreprocessorOptions &InitOpts,
+                                   const PCHContainerReader &PCHContainerRdr,
+                                   const FrontendOptions &FEOpts,
+                                   const CodeGenOptions &CodeGenOpts) {
   const LangOptions &LangOpts = PP.getLangOpts();
   std::string PredefineBuffer;
   PredefineBuffer.reserve(4080);
@@ -1416,6 +1426,11 @@ void clang::InitializePreprocessor(
   InitializeStandardPredefinedMacros(PP.getTargetInfo(), PP.getLangOpts(),
                                      FEOpts, Builder);
 
+  // The PGO instrumentation profile macros are driven by options
+  // -fprofile[-instr]-generate/-fcs-profile-generate/-fprofile[-instr]-use,
+  // hence they are not guarded by InitOpts.UsePredefines.
+  InitializePGOProfileMacros(CodeGenOpts, Builder);
+
   // Add on the predefines from the driver.  Wrap in a #line directive to report
   // that they come from the command line.
   Builder.append("# 1 \"<command line>\" 1");
diff --git a/clang/test/Profile/c-general.c b/clang/test/Profile/c-general.c
index b841f9c3d2a1d1..fa9eb7ebc78274 100644
--- a/clang/test/Profile/c-general.c
+++ b/clang/test/Profile/c-general.c
@@ -9,6 +9,15 @@
 // Also check compatibility with older profiles.
 // RUN: %clang_cc1 -triple x86_64-apple-macosx10.9 -main-file-name c-general.c %s -o - -emit-llvm -fprofile-instrument-use-path=%S/Inputs/c-general.profdata.v1 | FileCheck -allow-deprecated-dag-overlap  -check-prefix=PGOUSE %s
 
+// RUN: %clang -fprofile-generate -E -dM %s | FileCheck -match-full-lines -check-prefix=PROFGENMACRO %s
+// RUN: %clang -fprofile-instr-generate -E -dM %s | FileCheck -match-full-lines -check-prefix=PROFGENMACRO %s
+// RUN: %clang -fcs-profile-generate -E -dM %s | FileCheck -match-full-lines -check-prefix=PROFGENMACRO %s
+//
+// RUN: %clang -fprofile-use=%t.profdata -E -dM %s | FileCheck -match-full-lines -check-prefix=PROFUSEMACRO %s
+
+// PROFGENMACRO:#define __LLVM_INSTR_PROFILE_GENERATE 1
+// PROFUSEMACRO:#define __LLVM_INSTR_PROFILE_USE 1
+
 // PGOGEN: @[[SLC:__profc_simple_loops]] = private global [4 x i64] zeroinitializer
 // PGOGEN: @[[IFC:__profc_conditionals]] = private global [13 x i64] zeroinitializer
 // PGOGEN: @[[EEC:__profc_early_exits]] = private global [9 x i64] zeroinitializer
diff --git a/compiler-rt/include/CMakeLists.txt b/compiler-rt/include/CMakeLists.txt
index 78427beedb3cc4..7a100c66bbcfda 100644
--- a/compiler-rt/include/CMakeLists.txt
+++ b/compiler-rt/include/CMakeLists.txt
@@ -44,6 +44,7 @@ endif(COMPILER_RT_BUILD_ORC)
 if (COMPILER_RT_BUILD_PROFILE)
   set(PROFILE_HEADERS
     profile/InstrProfData.inc
+    profile/instr_prof_interface.h
     )
 endif(COMPILER_RT_BUILD_PROFILE)
 
diff --git a/compiler-rt/include/profile/instr_prof_interface.h b/compiler-rt/include/profile/instr_prof_interface.h
new file mode 100644
index 00000000000000..7d0516e5f6eaec
--- /dev/null
+++ b/compiler-rt/include/profile/instr_prof_interface.h
@@ -0,0 +1,66 @@
+/*===---- instr_prof_interface.h - Instrumentation PGO User Program API ----===
+ *
+ * Part of the LLVM Project, 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
+ *
+ *===-----------------------------------------------------------------------===
+ *
+ * This header provides a public interface for user programs to provide
+ * fine-grained control of counter reset and profile dumping.
+ *
+\*===---------------------------------------------------------------------===*/
+
+#ifndef COMPILER_RT_INSTR_PROFILING
+#define COMPILER_RT_INSTR_PROFILING
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef __LLVM_INSTR_PROFILE_GENERATE
+// Profile file reset and dump interfaces.
+// Only defined when `-fprofile-generate` is in effect.
+
+/*!
+ * \brief Interface to set all PGO counters to zero for the current process.
+ *
+ */
+void __llvm_profile_reset_counters(void);
+
+/*!
+ * \brief this is a wrapper interface to \c __llvm_profile_write_file.
+ * After this interface is invoked, an already dumped flag will be set
+ * so that profile won't be dumped again during program exit.
+ * Invocation of interface __llvm_profile_reset_counters will clear
+ * the flag. This interface is designed to be used to collect profile
+ * data from user selected hot regions. The use model is
+ *      __llvm_profile_reset_counters();
+ *      ... hot region 1
+ *      __llvm_profile_dump();
+ *      .. some other code
+ *      __llvm_profile_reset_counters();
+ *       ... hot region 2
+ *      __llvm_profile_dump();
+ *
+ *  It is expected that on-line profile merging is on with \c %m specifier
+ *  used in profile filename . If merging is  not turned on, user is expected
+ *  to invoke __llvm_profile_set_filename  to specify different profile names
+ *  for different regions before dumping to avoid profile write clobbering.
+ */
+int __llvm_profile_dump(void);
+
+// Interface to dump the current process' order file to disk.
+int __llvm_orderfile_dump(void);
+
+#else
+#define __llvm_profile_reset_counters()
+#define __llvm_profile_dump()
+#define __llvm_orderfile_dump()
+#endif
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif
diff --git a/compiler-rt/lib/profile/InstrProfiling.h b/compiler-rt/lib/profile/InstrProfiling.h
index 137115996748ce..3f2c75b5df9064 100644
--- a/compiler-rt/lib/profile/InstrProfiling.h
+++ b/compiler-rt/lib/profile/InstrProfiling.h
@@ -12,6 +12,9 @@
 #include "InstrProfilingPort.h"
 #include <stdio.h>
 
+#define __LLVM_INSTR_PROFILE_GENERATE
+#include "profile/instr_prof_interface.h"
+
 #define INSTR_PROF_VISIBILITY COMPILER_RT_VISIBILITY
 #include "profile/InstrProfData.inc"
 
@@ -100,12 +103,6 @@ ValueProfNode *__llvm_profile_begin_vnodes();
 ValueProfNode *__llvm_profile_end_vnodes();
 uint32_t *__llvm_profile_begin_orderfile();
 
-/*!
- * \brief Clear profile counters to zero.
- *
- */
-void __llvm_profile_reset_counters(void);
-
 /*!
  * \brief Merge profile data from buffer.
  *
@@ -156,29 +153,6 @@ void __llvm_profile_instrument_target_value(uint64_t TargetValue, void *Data,
 int __llvm_profile_write_file(void);
 
 int __llvm_orderfile_write_file(void);
-/*!
- * \brief this is a wrapper interface to \c __llvm_profile_write_file.
- * After this interface is invoked, an already dumped flag will be set
- * so that profile won't be dumped again during program exit.
- * Invocation of interface __llvm_profile_reset_counters will clear
- * the flag. This interface is designed to be used to collect profile
- * data from user selected hot regions. The use model is
- *      __llvm_profile_reset_counters();
- *      ... hot region 1
- *      __llvm_profile_dump();
- *      .. some other code
- *      __llvm_profile_reset_counters();
- *       ... hot region 2
- *      __llvm_profile_dump();
- *
- *  It is expected that on-line profile merging is on with \c %m specifier
- *  used in profile filename . If merging is  not turned on, user is expected
- *  to invoke __llvm_profile_set_filename  to specify different profile names
- *  for different regions before dumping to avoid profile write clobbering.
- */
-int __llvm_profile_dump(void);
-
-int __llvm_orderfile_dump(void);
 
 /*!
  * \brief Set the filename for writing instrumentation data.
diff --git a/compiler-rt/test/profile/instrprof-api.c b/compiler-rt/test/profile/instrprof-api.c
new file mode 100644
index 00000000000000..600fbb575feea3
--- /dev/null
+++ b/compiler-rt/test/profile/instrprof-api.c
@@ -0,0 +1,26 @@
+// RUN: %clang_profgen %s -S -emit-llvm -o - | FileCheck %s --check-prefix=PROFGEN
+// RUN: %clang_profgen -o %t %s
+// RUN: env LLVM_PROFILE_FILE=%t.profraw %run %t
+// RUN: llvm-profdata merge -o %t.profdata %t.profraw
+// RUN: %clang_profuse=%t.profdata %s -S -emit-llvm -o - | FileCheck %s --check-prefix=PROFUSE
+#include "profile/instr_profiling.h"
+
+__attribute__((noinline)) int bar() { return 4; }
+
+int foo() {
+  __llvm_profile_reset_counters();
+  // PROFGEN: call void @__llvm_profile_reset_counters()
+  // PROFUSE-NOT: call void @__llvm_profile_reset_counters()
+  return bar();
+}
+
+int main() {
+  int z = foo() + 3;
+  __llvm_profile_dump();
+  // PROFGEN: %call1 = call signext i32 @__llvm_profile_dump()
+  // PROFUSE-NOT: %call1 = call signext i32 @__llvm_profile_dump()
+  __llvm_orderfile_dump();
+  // PROFGEN: %call2 = call signext i32 @__llvm_orderfile_dump()
+  // PROFUSE-NOT: %call2 = call signext i32 @__llvm_orderfile_dump()
+  return z + bar() - 11;
+}

qiongsiwu · 2023-12-27T21:15:18Z

Note to reviewers: I am only adding these four PGO functions because I am not sure if more should be added. Please let me know, and I will revise the PR.

teresajohnson · 2023-12-27T21:29:50Z

The way we have done this in the past is to declare these as weak symbols and check if they exist before calling. E.g.:

extern "C" __attribute__((weak)) int __llvm_profile_dump(void);

if (__llvm_profile_dump)
      if (__llvm_profile_dump() != 0) { ...

Not necessarily opposed to adding the macros etc, but the advantage of the weak symbol approach vs what you have here is that the user code can check the return values.

snehasish · 2023-12-27T21:32:06Z

@teresajohnson I mentioned the same thing on discourse but it seems like linking on AIX does not support this model.

compiler-rt/lib/profile/InstrProfiling.h

compiler-rt/include/CMakeLists.txt

compiler-rt/test/profile/instrprof-api.c

clang/lib/Frontend/InitPreprocessor.cpp

teresajohnson · 2023-12-27T21:58:14Z

@teresajohnson I mentioned the same thing on discourse but it seems like linking on AIX does not support this model.

I see. Perhaps instead of defining these away completely, they should be defined to a dummy function with the same signature that always returns success (0 I think)? Alternatively, not define them at all when __LLVM_INSTR_PROFILE_GENERATE not defined and have the user guard calls by #ifdef __LLVM_INSTR_PROFILE_GENERATE. Otherwise, the user either cannot check the return values, or they have to guard their usage by a check of __LLVM_INSTR_PROFILE_GENERATE anyway.

qiongsiwu

Thanks so much @snehasish for the fast review! I have two questions regarding your comments. I will address the remaining comments soon as well!

compiler-rt/include/CMakeLists.txt

compiler-rt/lib/profile/InstrProfiling.h

qiongsiwu · 2023-12-27T23:28:30Z

@teresajohnson I mentioned the same thing on discourse but it seems like linking on AIX does not support this model.

I see. Perhaps instead of defining these away completely, they should be defined to a dummy function with the same signature that always returns success (0 I think)? Alternatively, not define them at all when __LLVM_INSTR_PROFILE_GENERATE not defined and have the user guard calls by #ifdef __LLVM_INSTR_PROFILE_GENERATE. Otherwise, the user either cannot check the return values, or they have to guard their usage by a check of __LLVM_INSTR_PROFILE_GENERATE anyway.

Ah good catch! Thanks so much! The definitions of __llvm_profile_dump and __llvm_orderfile_dump are revised to (0) so they can be used in if conditions. See cce25f0#diff-c21b547d913313490258f0fdb733251d783c5c5a242429ccc2fa5672914f22a2R58.

…ion to support setting profile file name.

snehasish

Thanks for your patience with my comments!

compiler-rt/test/profile/Linux/instrprof-weak-symbol.c

compiler-rt/lib/profile/InstrProfiling.h

clang/lib/Frontend/InitPreprocessor.cpp

qiongsiwu

@snehasish I appreciate your timely feedback! The latest commit aims at addressing all the comments.

clang/lib/Frontend/InitPreprocessor.cpp

compiler-rt/test/profile/Linux/instrprof-weak-symbol.c

compiler-rt/lib/profile/InstrProfiling.h

teresajohnson · 2024-01-03T15:16:08Z

I realized one problem during testing IRPGO (thanks again for the suggestion @minglotus-6 !).

A function's control flow may change between -fprofile-generate and -fprofile-use when we make use of definitions in the new header. For example, one may have the following code:
#include "profile/instr_prof_interface.h"

void main() {
   ...
  if (__llvm_profile_dump())
    return error;
  
  cleanup();
}
During -fprofile-generate, __llvm_profile_dump is a declared name and main's control flow includes a branch to return error;. During -fprofile-use, __llvm_profile_dump() is replaced by (0) and the frontend eliminates the if statement and the branch to return error. Such control flow change can lead to PGO warnings (hash mismatch).

I think it may be OK to keep the PR this way because the new macros can potentially cause control flow changes directly as well. The documentation is updated (https://github.com/llvm/llvm-project/pull/76471/files#diff-7389be311daf0b9b476c876bef04245fa3c0ad9337ce865682174bd77d53b648R2908) to advise against using these APIs in a program's hot regions and warn about possible impact on control flow.

Do you all think this is reasonable?

That's probably ok, as it doesn't make sense to do dumping etc in a hot region of code anyway. An alternate suggestion is to make these functions real functions that simply return 0 instead of #defined to 0. But that may not avoid the issue described above because early inlining will likely inline and simplify the code before IR PGO matching anyway.

qiongsiwu · 2024-01-09T15:37:47Z

Landing this PR. It seems that the format error is not caused by any changes in this PR.

vitalybuka · 2024-01-09T17:45:18Z

Breaks https://lab.llvm.org/buildbot/#/builders/127/builds/60635
Please fix or revert.

qiongsiwu · 2024-01-09T18:10:33Z

Breaks https://lab.llvm.org/buildbot/#/builders/127/builds/60635 Please fix or revert.

Thanks for reporting the problem @vitalybuka !

I don't have a Windows machine to reproduce the issue. It is not clear to me how the IR can contain names like "??_C@_0BA@MIKMMAII@rawprof?4profraw?$AA@". Do we have some special name mangling treatment on Windows?

I will modify the test to check for a more general pattern, but I will not know the result till the fix lands.

mingmingl-llvm · 2024-01-09T18:26:25Z

Breaks https://lab.llvm.org/buildbot/#/builders/127/builds/60635 Please fix or revert.

Thanks for reporting the problem @vitalybuka !

I don't have a Windows machine to reproduce the issue. It is not clear to me how the IR can contain names like "??_C@_0BA@MIKMMAII@rawprof?4profraw?$AA@". Do we have some special name mangling treatment on Windows?

I will modify the test to check for a more general pattern, but I will not know the result till the fix lands.

Sometimes godbolt output (like https://godbolt.org/z/MxbjcnanW) could be faster and more convenient (e.g., there is no need to get windows executable to for debugging, only LLVM IR is needed).

qiongsiwu · 2024-01-09T18:30:28Z

Sometimes godbolt output (like https://godbolt.org/z/MxbjcnanW) could be faster and more convenient (e.g., there is no need to get windows executable to for debugging, only LLVM IR is needed).

Thanks for the pointer! Yup godbolt can indeed reproduce IR quite well. https://godbolt.org/z/b7G1PnxME

Working on a fix.

Update: sorry I missed the link in the quoted comment. Thanks for the example!

#76471 introduced a new test but the check lines have over-restrictive patterns for a string variable name that cause test failures on Windows (e.g. https://lab.llvm.org/buildbot/#/builders/127/builds/60637/steps/4/logs/stdio). This PR fixes the test.

)" Issue #77546 This reverts commit 07c9189.

#76471 caused buildbot failures on Windows. For more details, see #77546. This PR revises the test and relands #76471.

This PR exposes four PGO functions - `__llvm_profile_set_filename` - `__llvm_profile_reset_counters`, - `__llvm_profile_dump` - `__llvm_orderfile_dump` to user programs through the new header `instr_prof_interface.h` under `compiler-rt/include/profile`. This way, the user can include the header `profile/instr_prof_interface.h` to introduce these four names to their programs. Additionally, this PR defines macro `__LLVM_INSTR_PROFILE_GENERATE` when the program is compiled with profile generation, and defines macro `__LLVM_INSTR_PROFILE_USE` when the program is compiled with profile use. `__LLVM_INSTR_PROFILE_GENERATE` together with `instr_prof_interface.h` define the PGO functions only when the program is compiled with profile generation. When profile generation is off, these PGO functions are defined away and leave no trace in the user's program. Background: https://discourse.llvm.org/t/pgo-are-the-llvm-profile-functions-stable-c-apis-across-llvm-releases/75832

llvm#76471 introduced a new test but the check lines have over-restrictive patterns for a string variable name that cause test failures on Windows (e.g. https://lab.llvm.org/buildbot/#/builders/127/builds/60637/steps/4/logs/stdio). This PR fixes the test.

…m#76471)" Issue llvm#77546 This reverts commit 07c9189.

Qiongsi Wu added 4 commits December 27, 2023 13:05

Initial commit

6c9381e

Frontend minor cleanup and adding a test

a6c3b46

Refactoring tests, adding profile-use macro

18ec4ac

Fix header comment

b741a55

llvmbot added clang Clang issues not falling into any other category compiler-rt clang-tidy clang:frontend Language frontend issues, e.g. anything involving "Sema" PGO Profile Guided Optimizations labels Dec 27, 2023

qiongsiwu requested review from mingmingl-llvm, david-xl and w2yehia December 27, 2023 21:16

snehasish reviewed Dec 27, 2023

View reviewed changes

compiler-rt/lib/profile/InstrProfiling.h Show resolved Hide resolved

compiler-rt/include/CMakeLists.txt Show resolved Hide resolved

compiler-rt/test/profile/instrprof-api.c Show resolved Hide resolved

clang/lib/Frontend/InitPreprocessor.cpp Show resolved Hide resolved

Fix test case after header renaming.

13a4bb3

qiongsiwu commented Dec 27, 2023

View reviewed changes

compiler-rt/include/CMakeLists.txt Show resolved Hide resolved

compiler-rt/lib/profile/InstrProfiling.h Show resolved Hide resolved

Address review comments

cce25f0

qiongsiwu self-assigned this Dec 28, 2023

Adding a new test to cover weak symbols. Adding a new interface funct…

ec47868

…ion to support setting profile file name.

qiongsiwu requested a review from snehasish December 28, 2023 14:49

snehasish reviewed Dec 28, 2023

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compiler-rt/test/profile/Linux/instrprof-weak-symbol.c Outdated Show resolved Hide resolved

compiler-rt/lib/profile/InstrProfiling.h Outdated Show resolved Hide resolved

clang/lib/Frontend/InitPreprocessor.cpp Show resolved Hide resolved

Address code review

29086fc

qiongsiwu commented Dec 29, 2023

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Qiongsi Wu added 2 commits December 28, 2023 22:25

Fixing documentation build error.

8e2bf69

Adding missing line break in documentation.

6f9a443

w2yehia approved these changes Jan 9, 2024

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qiongsiwu merged commit 07c9189 into llvm:main Jan 9, 2024

qiongsiwu mentioned this pull request Jan 9, 2024

[PGO] Fix instrprof-api.c on Windows #77508

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vitalybuka mentioned this pull request Jan 10, 2024

Multiple bots are broken after #76471 #77546

Closed

vitalybuka added a commit that referenced this pull request Jan 10, 2024

Revert "[PGO] Exposing PGO's Counter Reset and File Dumping APIs (#76471

a828cda

)" Issue #77546 This reverts commit 07c9189.

qiongsiwu mentioned this pull request Jan 16, 2024

[PGO] Reland PGO's Counter Reset and File Dumping APIs #76471 #78285

Merged

qiongsiwu pushed a commit to qiongsiwu/llvm-project that referenced this pull request Jan 17, 2024

Reland llvm#76471

ebae715

qiongsiwu added a commit that referenced this pull request Jan 22, 2024

[PGO] Reland PGO's Counter Reset and File Dumping APIs #76471 (#78285)

4f21fb8

#76471 caused buildbot failures on Windows. For more details, see #77546. This PR revises the test and relands #76471.

justinfargnoli pushed a commit to justinfargnoli/llvm-project that referenced this pull request Jan 28, 2024

Revert "[PGO] Exposing PGO's Counter Reset and File Dumping APIs (llv…

cd9edf9

…m#76471)" Issue llvm#77546 This reverts commit 07c9189.

[PGO] Exposing PGO's Counter Reset and File Dumping APIs #76471

[PGO] Exposing PGO's Counter Reset and File Dumping APIs #76471

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