PGO: Use the main file name to help distinguish functions with local linkage.

In addition, for all functions, use the name from the llvm::Function to
identify the function in the profile data. Compute that "function name",
including the file name for local functions, once when assigning the PGO
counters and store it in the CodeGenPGO class.

Move the code to add InlineHint and Cold attributes out of StartFunction(),
because the "function name" string isn't available at that point.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@203075 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index d0f1cb6b25889a71326af76dee440910cf81c35d..975ae6cb46b3436f2cd13064639fdb45c8c9ab1a 100644 (file)
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -589,15 +589,6 @@ void CodeGenFunction::StartFunction(GlobalDecl GD,
   if (CGM.getCodeGenOpts().InstrumentForProfiling)
     EmitMCountInstrumentation();
 
-  if (CGM.getPGOData() && D) {
-    // Turn on InlineHint attribute for hot functions.
-    if (CGM.getPGOData()->isHotFunction(CGM.getMangledName(GD)))
-      Fn->addFnAttr(llvm::Attribute::InlineHint);
-    // Turn on Cold attribute for cold functions.
-    else if (CGM.getPGOData()->isColdFunction(CGM.getMangledName(GD)))
-      Fn->addFnAttr(llvm::Attribute::Cold);
-  }
-
   if (RetTy->isVoidType()) {
     // Void type; nothing to return.
     ReturnValue = 0;
@@ -770,7 +761,7 @@ void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn,
   StartFunction(GD, ResTy, Fn, FnInfo, Args, BodyRange.getBegin());
 
   // Generate the body of the function.
-  PGO.assignRegionCounters(GD.getDecl(), CGM.getMangledName(GD));
+  PGO.assignRegionCounters(GD.getDecl(), CurFn);
   if (isa<CXXDestructorDecl>(FD))
     EmitDestructorBody(Args);
   else if (isa<CXXConstructorDecl>(FD))
@@ -831,7 +822,7 @@ void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn,
   if (!CurFn->doesNotThrow())
     TryMarkNoThrow(CurFn);
 
-  PGO.emitWriteoutFunction(CGM.getMangledName(CurGD));
+  PGO.emitWriteoutFunction();
   PGO.destroyRegionCounters();
 }
 

diff --git a/lib/CodeGen/CodeGenPGO.cpp b/lib/CodeGen/CodeGenPGO.cpp
index 658fb2c9986c0b569019f368c91a89e71ccc2e7e..6678c37929b238e3adfae5cff724d5fc84ab4352 100644 (file)
--- a/lib/CodeGen/CodeGenPGO.cpp
+++ b/lib/CodeGen/CodeGenPGO.cpp
@@ -161,7 +161,32 @@ bool PGOProfileData::getFunctionCounts(StringRef FuncName,
   return false;
 }
 
-void CodeGenPGO::emitWriteoutFunction(StringRef Name) {
+void CodeGenPGO::setFuncName(llvm::Function *Fn) {
+  StringRef Func = Fn->getName();
+
+  // Function names may be prefixed with a binary '1' to indicate
+  // that the backend should not modify the symbols due to any platform
+  // naming convention. Do not include that '1' in the PGO profile name.
+  if (Func[0] == '\1')
+    Func = Func.substr(1);
+
+  if (!Fn->hasLocalLinkage()) {
+    FuncName = new std::string(Func);
+    return;
+  }
+
+  // For local symbols, prepend the main file name to distinguish them.
+  // Do not include the full path in the file name since there's no guarantee
+  // that it will stay the same, e.g., if the files are checked out from
+  // version control in different locations.
+  FuncName = new std::string(CGM.getCodeGenOpts().MainFileName);
+  if (FuncName->empty())
+    FuncName->assign("<unknown>");
+  FuncName->append(":");
+  FuncName->append(Func);
+}
+
+void CodeGenPGO::emitWriteoutFunction() {
   if (!CGM.getCodeGenOpts().ProfileInstrGenerate)
     return;
 
@@ -206,7 +231,7 @@ void CodeGenPGO::emitWriteoutFunction(StringRef Name) {
     CGM.getModule().getOrInsertFunction("llvm_pgo_emit", FTy);
 
   llvm::Constant *NameString =
-    CGM.GetAddrOfConstantCString(Name, "__llvm_pgo_name");
+    CGM.GetAddrOfConstantCString(getFuncName(), "__llvm_pgo_name");
   NameString = llvm::ConstantExpr::getBitCast(NameString, Int8PtrTy);
   PGOBuilder.CreateCall3(EmitFunc, NameString,
                          PGOBuilder.getInt32(NumRegionCounters),
@@ -727,19 +752,27 @@ namespace {
   };
 }
 
-void CodeGenPGO::assignRegionCounters(const Decl *D, StringRef Name) {
+void CodeGenPGO::assignRegionCounters(const Decl *D, llvm::Function *Fn) {
   bool InstrumentRegions = CGM.getCodeGenOpts().ProfileInstrGenerate;
   PGOProfileData *PGOData = CGM.getPGOData();
   if (!InstrumentRegions && !PGOData)
     return;
   if (!D)
     return;
+  setFuncName(Fn);
   mapRegionCounters(D);
   if (InstrumentRegions)
     emitCounterVariables();
   if (PGOData) {
-    loadRegionCounts(Name, PGOData);
+    loadRegionCounts(PGOData);
     computeRegionCounts(D);
+
+    // Turn on InlineHint attribute for hot functions.
+    if (PGOData->isHotFunction(getFuncName()))
+      Fn->addFnAttr(llvm::Attribute::InlineHint);
+    // Turn on Cold attribute for cold functions.
+    else if (PGOData->isColdFunction(getFuncName()))
+      Fn->addFnAttr(llvm::Attribute::Cold);
   }
 }
 
@@ -779,13 +812,13 @@ void CodeGenPGO::emitCounterIncrement(CGBuilderTy &Builder, unsigned Counter) {
   Builder.CreateStore(Count, Addr);
 }
 
-void CodeGenPGO::loadRegionCounts(StringRef Name, PGOProfileData *PGOData) {
+void CodeGenPGO::loadRegionCounts(PGOProfileData *PGOData) {
   // For now, ignore the counts from the PGO data file only if the number of
   // counters does not match. This could be tightened down in the future to
   // ignore counts when the input changes in various ways, e.g., by comparing a
   // hash value based on some characteristics of the input.
   RegionCounts = new std::vector<uint64_t>();
-  if (PGOData->getFunctionCounts(Name, *RegionCounts) ||
+  if (PGOData->getFunctionCounts(getFuncName(), *RegionCounts) ||
       RegionCounts->size() != NumRegionCounters) {
     delete RegionCounts;
     RegionCounts = 0;

diff --git a/lib/CodeGen/CodeGenPGO.h b/lib/CodeGen/CodeGenPGO.h
index c9c0e8b004c1ac3a49c487cb9886ef781a171ad0..0fc570ad9cda4e9d8873126b16d10c18cb7780dc 100644 (file)
--- a/lib/CodeGen/CodeGenPGO.h
+++ b/lib/CodeGen/CodeGenPGO.h
@@ -56,6 +56,7 @@ public:
 class CodeGenPGO {
 private:
   CodeGenModule &CGM;
+  std::string *FuncName;
 
   unsigned NumRegionCounters;
   llvm::GlobalVariable *RegionCounters;
@@ -66,15 +67,22 @@ private:
 
 public:
   CodeGenPGO(CodeGenModule &CGM)
-    : CGM(CGM), NumRegionCounters(0), RegionCounters(0), RegionCounterMap(0),
-      StmtCountMap(0), RegionCounts(0), CurrentRegionCount(0) {}
-  ~CodeGenPGO() {}
+    : CGM(CGM), FuncName(0), NumRegionCounters(0), RegionCounters(0),
+      RegionCounterMap(0), StmtCountMap(0), RegionCounts(0),
+      CurrentRegionCount(0) {}
+  ~CodeGenPGO() {
+    if (FuncName) delete FuncName;
+  }
 
   /// Whether or not we have PGO region data for the current function. This is
   /// false both when we have no data at all and when our data has been
   /// discarded.
   bool haveRegionCounts() const { return RegionCounts != 0; }
 
+  /// Get the string used to identify this function in the profile data.
+  /// For functions with local linkage, this includes the main file name.
+  const StringRef getFuncName() const { return StringRef(*FuncName); }
+
   /// Return the counter value of the current region.
   uint64_t getCurrentRegionCount() const { return CurrentRegionCount; }
 
@@ -118,9 +126,9 @@ public:
   /// function. Does nothing if instrumentation is not enabled and either
   /// generates global variables or associates PGO data with each of the
   /// counters depending on whether we are generating or using instrumentation.
-  void assignRegionCounters(const Decl *D, StringRef Name);
+  void assignRegionCounters(const Decl *D, llvm::Function *Fn);
   /// Emit code to write counts for a given function to disk, if necessary.
-  void emitWriteoutFunction(StringRef Name);
+  void emitWriteoutFunction();
   /// Clean up region counter state. Must be called if assignRegionCounters is
   /// used.
   void destroyRegionCounters();
@@ -129,9 +137,10 @@ public:
   static llvm::Function *emitInitialization(CodeGenModule &CGM);
 
 private:
+  void setFuncName(llvm::Function *Fn);
   void mapRegionCounters(const Decl *D);
   void computeRegionCounts(const Decl *D);
-  void loadRegionCounts(StringRef Name, PGOProfileData *PGOData);
+  void loadRegionCounts(PGOProfileData *PGOData);
   void emitCounterVariables();
 
   /// Emit code to increment the counter at the given index

diff --git a/test/CodeGen/Inputs/instr-profile.pgodata b/test/CodeGen/Inputs/instr-profile.pgodata
index 07e763ed1decec38a96c1b67d7a9596f9dec0834..f6337d233298c0b242646eca315081942441a455 100644 (file)
--- a/test/CodeGen/Inputs/instr-profile.pgodata
+++ b/test/CodeGen/Inputs/instr-profile.pgodata
@@ -132,3 +132,7 @@ no_usable_data 5
 main 1
 1
 
+instr-profile.c:static_func 2
+1
+10
+

diff --git a/test/CodeGen/instr-profile.c b/test/CodeGen/instr-profile.c
index c982dcb7582e448b7aada6071c701eb8f31bc46b..f753f8306d44cab70673853e78fa456632b58b0d 100644 (file)
--- a/test/CodeGen/instr-profile.c
+++ b/test/CodeGen/instr-profile.c
@@ -18,6 +18,7 @@
 // PGOGEN: @[[BLC:__llvm_pgo_ctr[0-9]*]] = private global [9 x i64]  zeroinitializer
 // PGOGEN: @[[NOC:__llvm_pgo_ctr[0-9]*]] = private global [2 x i64]  zeroinitializer
 // PGOGEN: @[[MAC:__llvm_pgo_ctr[0-9]*]] = private global [1 x i64]  zeroinitializer
+// PGOGEN: @[[STF:__llvm_pgo_ctr[0-9]*]] = private global [2 x i64]  zeroinitializer
 
 // PGOGEN-LABEL: @simple_loops()
 // PGOUSE-LABEL: @simple_loops()
@@ -445,6 +446,16 @@ void no_usable_data() {
   // PGOUSE-NOT: br {{.*}} !prof ![0-9]+
 }
 
+// PGOGEN-LABEL: @static_func()
+// PGOUSE-LABEL: @static_func()
+// PGOGEN: store {{.*}} @[[STF]], i64 0, i64 0
+static void static_func() {
+  // PGOGEN: store {{.*}} @[[STF]], i64 0, i64 1
+  // PGOUSE: br {{.*}} !prof ![[ST1:[0-9]+]]
+  for (int i = 0; i < 10; ++i) {
+  }
+}
+
 // PGOUSE-DAG: ![[SL1]] = metadata !{metadata !"branch_weights", i32 101, i32 2}
 // PGOUSE-DAG: ![[SL2]] = metadata !{metadata !"branch_weights", i32 101, i32 2}
 // PGOUSE-DAG: ![[SL3]] = metadata !{metadata !"branch_weights", i32 76, i32 2}
@@ -513,6 +524,7 @@ void no_usable_data() {
 // PGOUSE-DAG: ![[BL6]] = metadata !{metadata !"branch_weights", i32 51, i32 2}
 // PGOUSE-DAG: ![[BL7]] = metadata !{metadata !"branch_weights", i32 26, i32 27}
 // PGOUSE-DAG: ![[BL8]] = metadata !{metadata !"branch_weights", i32 51, i32 2}
+// PGOUSE-DAG: ![[ST1]] = metadata !{metadata !"branch_weights", i32 11, i32 2}
 
 int main(int argc, const char *argv[]) {
   simple_loops();
@@ -525,5 +537,6 @@ int main(int argc, const char *argv[]) {
   boolop_loops();
   do_fallthrough();
   no_usable_data();
+  static_func();
   return 0;
 }