[flang-commits] [clang] [flang] [flang] Support flag -finstrument-functions (PR #137996)
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Wed Apr 30 10:10:22 PDT 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-flang-driver
@llvm/pr-subscribers-clang-driver
Author: Anchu Rajendran S (anchuraj)
<details>
<summary>Changes</summary>
`f-instrument-functions` helps in profiling functions. This PR adds support for the option by defining values for function attributes `instrument_function_entry` and `instrument_function_exit`. LLVM Backend adds calls to the functions `__cyg_profile_func_enter` and `__cyg_profile_func_exit` which can be intercepted by user to profile every function.
LLVM Dialect support is added in https://github.com/llvm/llvm-project/pull/137856. These changes are to support https://github.com/llvm/llvm-project/issues/112330.
---
Full diff: https://github.com/llvm/llvm-project/pull/137996.diff
9 Files Affected:
- (modified) clang/include/clang/Driver/Options.td (+6-4)
- (modified) clang/lib/Driver/ToolChains/Flang.cpp (+2-1)
- (modified) flang/include/flang/Frontend/CodeGenOptions.h (+2)
- (modified) flang/include/flang/Optimizer/Transforms/Passes.td (+8)
- (modified) flang/include/flang/Tools/CrossToolHelpers.h (+7-1)
- (modified) flang/lib/Frontend/CompilerInvocation.cpp (+4)
- (modified) flang/lib/Optimizer/Passes/Pipelines.cpp (+2-1)
- (modified) flang/lib/Optimizer/Transforms/FunctionAttr.cpp (+10)
- (added) flang/test/Driver/func-attr-instrument-functions.f90 (+9)
``````````diff
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index c0f469e04375c..8a3b74c397b95 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -2824,10 +2824,12 @@ def finput_charset_EQ : Joined<["-"], "finput-charset=">,
Visibility<[ClangOption, FlangOption, FC1Option]>, Group<f_Group>,
HelpText<"Specify the default character set for source files">;
def fexec_charset_EQ : Joined<["-"], "fexec-charset=">, Group<f_Group>;
-def finstrument_functions : Flag<["-"], "finstrument-functions">, Group<f_Group>,
- Visibility<[ClangOption, CC1Option]>,
- HelpText<"Generate calls to instrument function entry and exit">,
- MarshallingInfoFlag<CodeGenOpts<"InstrumentFunctions">>;
+def finstrument_functions
+ : Flag<["-"], "finstrument-functions">,
+ Group<f_Group>,
+ Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>,
+ HelpText<"Generate calls to instrument function entry and exit">,
+ MarshallingInfoFlag<CodeGenOpts<"InstrumentFunctions">>;
def finstrument_functions_after_inlining : Flag<["-"], "finstrument-functions-after-inlining">, Group<f_Group>,
Visibility<[ClangOption, CC1Option]>,
HelpText<"Like -finstrument-functions, but insert the calls after inlining">,
diff --git a/clang/lib/Driver/ToolChains/Flang.cpp b/clang/lib/Driver/ToolChains/Flang.cpp
index e9d5a844ab073..a407e295c09bd 100644
--- a/clang/lib/Driver/ToolChains/Flang.cpp
+++ b/clang/lib/Driver/ToolChains/Flang.cpp
@@ -128,7 +128,8 @@ void Flang::addOtherOptions(const ArgList &Args, ArgStringList &CmdArgs) const {
options::OPT_std_EQ, options::OPT_W_Joined,
options::OPT_fconvert_EQ, options::OPT_fpass_plugin_EQ,
options::OPT_funderscoring, options::OPT_fno_underscoring,
- options::OPT_funsigned, options::OPT_fno_unsigned});
+ options::OPT_funsigned, options::OPT_fno_unsigned,
+ options::OPT_finstrument_functions});
llvm::codegenoptions::DebugInfoKind DebugInfoKind;
if (Args.hasArg(options::OPT_gN_Group)) {
diff --git a/flang/include/flang/Frontend/CodeGenOptions.h b/flang/include/flang/Frontend/CodeGenOptions.h
index 2b4e823b3fef4..93711ae382f17 100644
--- a/flang/include/flang/Frontend/CodeGenOptions.h
+++ b/flang/include/flang/Frontend/CodeGenOptions.h
@@ -81,6 +81,8 @@ class CodeGenOptions : public CodeGenOptionsBase {
/// Options to add to the linker for the object file
std::vector<std::string> DependentLibs;
+ bool InstrumentFunctions{false};
+
// The RemarkKind enum class and OptRemark struct are identical to what Clang
// has
// TODO: Share with clang instead of re-implementing here
diff --git a/flang/include/flang/Optimizer/Transforms/Passes.td b/flang/include/flang/Optimizer/Transforms/Passes.td
index c59416fa2c024..9b6919eec3f73 100644
--- a/flang/include/flang/Optimizer/Transforms/Passes.td
+++ b/flang/include/flang/Optimizer/Transforms/Passes.td
@@ -393,6 +393,14 @@ def FunctionAttr : Pass<"function-attr", "mlir::func::FuncOp"> {
clEnumValN(mlir::LLVM::framePointerKind::FramePointerKind::All, "All", ""),
clEnumValN(mlir::LLVM::framePointerKind::FramePointerKind::Reserved, "Reserved", "")
)}]>,
+ Option<"instrumentFunctionEntry", "instrument-function-entry",
+ "std::string", /*default=*/"",
+ "Sets the name of the profiling function called during function "
+ "entry">,
+ Option<"instrumentFunctionExit", "instrument-function-exit",
+ "std::string", /*default=*/"",
+ "Sets the name of the profiling function called during function "
+ "exit">,
Option<"noInfsFPMath", "no-infs-fp-math", "bool", /*default=*/"false",
"Set the no-infs-fp-math attribute on functions in the module.">,
Option<"noNaNsFPMath", "no-nans-fp-math", "bool", /*default=*/"false",
diff --git a/flang/include/flang/Tools/CrossToolHelpers.h b/flang/include/flang/Tools/CrossToolHelpers.h
index 1dbc18e2b348b..36828028d3239 100644
--- a/flang/include/flang/Tools/CrossToolHelpers.h
+++ b/flang/include/flang/Tools/CrossToolHelpers.h
@@ -102,13 +102,17 @@ struct MLIRToLLVMPassPipelineConfig : public FlangEPCallBacks {
UnsafeFPMath = mathOpts.getAssociativeMath() &&
mathOpts.getReciprocalMath() && NoSignedZerosFPMath &&
ApproxFuncFPMath && mathOpts.getFPContractEnabled();
+ if (opts.InstrumentFunctions) {
+ InstrumentFunctionsEntry = "__cyg_profile_func_enter";
+ InstrumentFunctionsExit = "__cyg_profile_func_exit";
+ }
}
llvm::OptimizationLevel OptLevel; ///< optimisation level
bool StackArrays = false; ///< convert memory allocations to alloca.
bool Underscoring = true; ///< add underscores to function names.
bool LoopVersioning = false; ///< Run the version loop pass.
- bool AliasAnalysis = false; ///< Add TBAA tags to generated LLVMIR
+ bool AliasAnalysis = false; ///< Add TBAA tags to generated LLVMIR.
llvm::codegenoptions::DebugInfoKind DebugInfo =
llvm::codegenoptions::NoDebugInfo; ///< Debug info generation.
llvm::FramePointerKind FramePointerKind =
@@ -124,6 +128,8 @@ struct MLIRToLLVMPassPipelineConfig : public FlangEPCallBacks {
bool UnsafeFPMath = false; ///< Set unsafe-fp-math attribute for functions.
bool NSWOnLoopVarInc = true; ///< Add nsw flag to loop variable increments.
bool EnableOpenMP = false; ///< Enable OpenMP lowering.
+ std::string InstrumentFunctionsEntry = "";
+ std::string InstrumentFunctionsExit = "";
};
struct OffloadModuleOpts {
diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index 6f87a18d69c3d..ffb16b11f6af0 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -310,6 +310,10 @@ static void parseCodeGenArgs(Fortran::frontend::CodeGenOptions &opts,
args.filtered(clang::driver::options::OPT_fembed_offload_object_EQ))
opts.OffloadObjects.push_back(a->getValue());
+ if (args.hasFlag(clang::driver::options::OPT_finstrument_functions,
+ clang::driver::options::OPT_finstrument_functions, false))
+ opts.InstrumentFunctions = true;
+
// -flto=full/thin option.
if (const llvm::opt::Arg *a =
args.getLastArg(clang::driver::options::OPT_flto_EQ)) {
diff --git a/flang/lib/Optimizer/Passes/Pipelines.cpp b/flang/lib/Optimizer/Passes/Pipelines.cpp
index 130cbe72ec273..795ddcbd821da 100644
--- a/flang/lib/Optimizer/Passes/Pipelines.cpp
+++ b/flang/lib/Optimizer/Passes/Pipelines.cpp
@@ -349,7 +349,8 @@ void createDefaultFIRCodeGenPassPipeline(mlir::PassManager &pm,
framePointerKind = mlir::LLVM::framePointerKind::FramePointerKind::None;
pm.addPass(fir::createFunctionAttr(
- {framePointerKind, config.NoInfsFPMath, config.NoNaNsFPMath,
+ {framePointerKind, config.InstrumentFunctionsEntry,
+ config.InstrumentFunctionsExit, config.NoInfsFPMath, config.NoNaNsFPMath,
config.ApproxFuncFPMath, config.NoSignedZerosFPMath, config.UnsafeFPMath,
""}));
diff --git a/flang/lib/Optimizer/Transforms/FunctionAttr.cpp b/flang/lib/Optimizer/Transforms/FunctionAttr.cpp
index c79843fac4ce2..43e4c1a7af3cd 100644
--- a/flang/lib/Optimizer/Transforms/FunctionAttr.cpp
+++ b/flang/lib/Optimizer/Transforms/FunctionAttr.cpp
@@ -28,6 +28,8 @@ namespace {
class FunctionAttrPass : public fir::impl::FunctionAttrBase<FunctionAttrPass> {
public:
FunctionAttrPass(const fir::FunctionAttrOptions &options) {
+ instrumentFunctionEntry = options.instrumentFunctionEntry;
+ instrumentFunctionExit = options.instrumentFunctionExit;
framePointerKind = options.framePointerKind;
noInfsFPMath = options.noInfsFPMath;
noNaNsFPMath = options.noNaNsFPMath;
@@ -72,6 +74,14 @@ void FunctionAttrPass::runOnOperation() {
auto llvmFuncOpName =
mlir::OperationName(mlir::LLVM::LLVMFuncOp::getOperationName(), context);
+ if (!instrumentFunctionEntry.empty())
+ func->setAttr(mlir::LLVM::LLVMFuncOp::getInstrumentFunctionEntryAttrName(
+ llvmFuncOpName),
+ mlir::StringAttr::get(context, instrumentFunctionEntry));
+ if (!instrumentFunctionExit.empty())
+ func->setAttr(mlir::LLVM::LLVMFuncOp::getInstrumentFunctionExitAttrName(
+ llvmFuncOpName),
+ mlir::StringAttr::get(context, instrumentFunctionExit));
if (noInfsFPMath)
func->setAttr(
mlir::LLVM::LLVMFuncOp::getNoInfsFpMathAttrName(llvmFuncOpName),
diff --git a/flang/test/Driver/func-attr-instrument-functions.f90 b/flang/test/Driver/func-attr-instrument-functions.f90
new file mode 100644
index 0000000000000..0ef81806e9fb9
--- /dev/null
+++ b/flang/test/Driver/func-attr-instrument-functions.f90
@@ -0,0 +1,9 @@
+! RUN: %flang -O1 -finstrument-functions -emit-llvm -S -o - %s 2>&1| FileCheck %s
+
+subroutine func
+end subroutine func
+
+! CHECK: define void @func_()
+! CHECK: {{.*}}call void @__cyg_profile_func_enter(ptr {{.*}}@func_, ptr {{.*}})
+! CHECK: {{.*}}call void @__cyg_profile_func_exit(ptr {{.*}}@func_, ptr {{.*}})
+! CHECK-NEXT: ret {{.*}}
``````````
</details>
https://github.com/llvm/llvm-project/pull/137996
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