[PATCH] D18569: [PGO] Move the instrumentation point closer to the value site.

[Betul Buyukkurt via llvm-commits]

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For terminator instructions, the value profiling instrumentation happens in a basic block other than where the value site resides. This CR moves the instrumentation point prior to the value site. Mostly NFC.

Repository:
  rL LLVM

http://reviews.llvm.org/D18569

Files:
  lib/CodeGen/CodeGenPGO.cpp
  test/Profile/c-indirect-call.c
  test/Profile/cxx-indirect-call.cpp

Index: test/Profile/cxx-indirect-call.cpp
===================================================================
--- /dev/null
+++ test/Profile/cxx-indirect-call.cpp
@@ -0,0 +1,21 @@
+// Check the value profiling instrinsics emitted by instrumentation.
+
+// RUN: %clangxx %s -o - -emit-llvm -S -fprofile-instr-generate -mllvm -enable-value-profiling -fexceptions -target %itanium_abi_triple | FileCheck %s
+
+void (*foo) (void);
+
+int main(int argc, const char *argv[]) {
+// CHECK:  [[REG1:%[0-9]+]] = load void ()*, void ()** @foo, align 4
+// CHECK-NEXT:  [[REG2:%[0-9]+]] = ptrtoint void ()* [[REG1]] to i64
+// CHECK-NEXT:  call void @__llvm_profile_instrument_target(i64 [[REG2]], i8* bitcast ({{.*}}* @__profd_main to i8*), i32 0)
+// CHECK-NEXT:  invoke void [[REG1]]()
+  try {
+    foo();
+  } catch (int) {}
+  return 0;
+}
+
+// CHECK: declare void @__llvm_profile_instrument_target(i64, i8*, i32)
+
+
+
Index: test/Profile/c-indirect-call.c
===================================================================
--- test/Profile/c-indirect-call.c
+++ test/Profile/c-indirect-call.c
@@ -1,13 +1,14 @@
-// Check the data structures emitted by instrumentation.
+// Check the value profiling instrinsics emitted by instrumentation.
+
 // RUN: %clang_cc1 -triple x86_64-apple-macosx10.9 -main-file-name c-indirect-call.c %s -o - -emit-llvm -fprofile-instrument=clang -mllvm -enable-value-profiling | FileCheck %s
 
 void (*foo)(void);
 
 int main(void) {
 // CHECK:  [[REG1:%[0-9]+]] = load void ()*, void ()** @foo, align 8
-// CHECK-NEXT:  call void [[REG1]]()
 // CHECK-NEXT:  [[REG2:%[0-9]+]] = ptrtoint void ()* [[REG1]] to i64
 // CHECK-NEXT:  call void @__llvm_profile_instrument_target(i64 [[REG2]], i8* bitcast ({{.*}}* @__profd_main to i8*), i32 0)
+// CHECK-NEXT:  call void [[REG1]]()
   foo();
   return 0;
 }
Index: lib/CodeGen/CodeGenPGO.cpp
===================================================================
--- lib/CodeGen/CodeGenPGO.cpp
+++ lib/CodeGen/CodeGenPGO.cpp
@@ -757,17 +757,18 @@
 
   bool InstrumentValueSites = CGM.getCodeGenOpts().hasProfileClangInstr();
   if (InstrumentValueSites && RegionCounterMap) {
-    llvm::LLVMContext &Ctx = CGM.getLLVMContext();
-    auto *I8PtrTy = llvm::Type::getInt8PtrTy(Ctx);
+    auto BuilderInsertPoint = Builder.saveIP();
+    Builder.SetInsertPoint(ValueSite);
     llvm::Value *Args[5] = {
-        llvm::ConstantExpr::getBitCast(FuncNameVar, I8PtrTy),
+        llvm::ConstantExpr::getBitCast(FuncNameVar, Builder.getInt8PtrTy()),
         Builder.getInt64(FunctionHash),
         Builder.CreatePtrToInt(ValuePtr, Builder.getInt64Ty()),
         Builder.getInt32(ValueKind),
         Builder.getInt32(NumValueSites[ValueKind]++)
     };
     Builder.CreateCall(
         CGM.getIntrinsic(llvm::Intrinsic::instrprof_value_profile), Args);
+    Builder.restoreIP(BuilderInsertPoint);
     return;
   }
 


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