Add -fprofile-sample-use

CHANGELOG.md

@@ -3,6 +3,7 @@
 #### Big news
 - Frontend, druntime and Phobos are at version [2.106.0](https://dlang.org/changelog/2.106.0.html). (#4522)
 - New command-line options `-fno-{exceptions,moduleinfo,rtti}` to selectively enable some `-betterC` effects. (#4522)
+- New command-line option `-fprofile-sample-use` for using sample-based profile data for optimization. Functionality and usage is identical to Clang's option with same name. (#4531).
 
 #### Platform support
 

driver/cl_options_instrumentation.cpp

@@ -31,7 +31,7 @@ cl::opt<std::string> IRPGOInstrGenFile(
              "'=<filename>' or LLVM_PROFILE_FILE env var)"),
     cl::ZeroOrMore, cl::ValueOptional);
 
-/// Option for generating IR-based PGO instrumentation (LLVM pass)
+/// Option for using IR-based PGO instrumentation (LLVM pass)
 cl::opt<std::string> IRPGOInstrUseFile(
     "fprofile-use", cl::ZeroOrMore, cl::value_desc("filename"),
     cl::desc("Use instrumentation data for profile-guided optimization"),
@@ -45,12 +45,20 @@ cl::opt<std::string> ASTPGOInstrGenFile(
              "'=<filename>' or LLVM_PROFILE_FILE env var)"),
     cl::ZeroOrMore, cl::ValueOptional);
 
-/// Option for generating frontend-based PGO instrumentation
+/// Option for using frontend-based PGO instrumentation
 cl::opt<std::string> ASTPGOInstrUseFile(
     "fprofile-instr-use", cl::ZeroOrMore, cl::value_desc("filename"),
     cl::desc("Use instrumentation data for profile-guided optimization"),
     cl::ValueRequired);
 
+/// Option for using sample-based PGO instrumentation
+cl::opt<std::string>
+    SamplePGOInstrUseFile("fprofile-sample-use", cl::Optional,
+                          cl::value_desc("filename"),
+                          cl::desc("Use instrumentation data for sample-based "
+                                   "profile guided optimizations"),
+                          cl::ValueRequired);
+
 cl::opt<int> fXRayInstructionThreshold(
     "fxray-instruction-threshold", cl::value_desc("value"),
     cl::desc("Sets the minimum function size to instrument with XRay"),
@@ -119,6 +127,9 @@ void initializeInstrumentationOptionsFromCmdline(const llvm::Triple &triple) {
   } else if (!IRPGOInstrUseFile.empty()) {
     pgoMode = PGO_IRBasedUse;
     global.params.datafileInstrProf = fromPathString(IRPGOInstrUseFile).ptr;
+  } else if (!SamplePGOInstrUseFile.empty()) {
+    pgoMode = PGO_SampleBasedUse;
+    global.params.datafileInstrProf = fromPathString(SamplePGOInstrUseFile).ptr;
   }
 
   if (dmdFunctionTrace)

driver/cl_options_instrumentation.h

@@ -43,6 +43,7 @@ enum PGOKind {
   PGO_ASTBasedUse,
   PGO_IRBasedInstr,
   PGO_IRBasedUse,
+  PGO_SampleBasedUse,
 };
 extern PGOKind pgoMode;
 inline bool isInstrumentingForPGO() {
@@ -59,5 +60,8 @@ inline bool isInstrumentingForIRBasedPGO() {
   return pgoMode == PGO_IRBasedInstr;
 }
 inline bool isUsingIRBasedPGOProfile() { return pgoMode == PGO_IRBasedUse; }
+inline bool isUsingSampleBasedPGOProfile() {
+  return pgoMode == PGO_SampleBasedUse;
+}
 
 } // namespace opts

gen/functions.cpp

@@ -1233,6 +1233,9 @@ void DtoDefineFunction(FuncDeclaration *fd, bool linkageAvailableExternally) {
   if (opts::fSplitStack && !hasNoSplitStackUDA(fd)) {
     func->addFnAttr("split-stack");
   }
+  if (opts::isUsingSampleBasedPGOProfile()) {
+    func->addFnAttr("use-sample-profile");
+  }
 
   llvm::BasicBlock *beginbb =
       llvm::BasicBlock::Create(gIR->context(), "", func);

gen/optimizer.cpp

@@ -557,6 +557,11 @@ static llvm::Optional<PGOOptions> getPGOOptions() {
                      PGOOptions::PGOAction::IRUse,
                      PGOOptions::CSPGOAction::NoCSAction,
                      debugInfoForProfiling, pseudoProbeForProfiling);
+  } else if (opts::isUsingSampleBasedPGOProfile()) {
+    return PGOOptions(global.params.datafileInstrProf, "", "",
+                     PGOOptions::PGOAction::SampleUse,
+                     PGOOptions::CSPGOAction::NoCSAction,
+                     debugInfoForProfiling, pseudoProbeForProfiling);
   }
 #if LDC_LLVM_VER < 1600
   return None;

tests/PGO/sample_based.d

@@ -0,0 +1,21 @@
+// Test basic use of sample-based PGO profile
+
+// REQUIRES: atleast_llvm1500
+
+// RUN: split-file %s %t
+// RUN: %ldc -O2 -c -gline-tables-only -output-ll -of=%t.ll -fprofile-sample-use=%t/pgo-sample.prof %t/testcase.d && FileCheck %s < %t.ll
+
+//--- pgo-sample.prof
+foo:100:100
+ 1: 100
+
+//--- testcase.d
+// CHECK: define{{.*}} @foo{{.*}} #[[ATTRID:[0-9]+]]{{.*}} !prof ![[PROFID:[0-9]+]]
+// CHECK: attributes #[[ATTRID]] = {{.*}} "use-sample-profile"
+// CHECK-DAG: "ProfileFormat", !"SampleProfile"
+// CHECK-DAG: "TotalCount", i64 100
+// CHECK-DAG: ![[PROFID]] = !{!"function_entry_count", i64 101}
+
+extern (C) int foo () {
+    return 1;
+}