[PGO] Allow value profile writer interface to allocated target buffer

Raw profile writer needs to write all data of one kind in one continuous block,
so the buffer needs to be pre-allocated and passed to the writer method in
pieces for function profile data. The change adds the support for raw value data
writing.

llvm-svn: 254219

3 files changed, 18 insertions, 13 deletions

diff --git a/llvm/include/llvm/ProfileData/InstrProf.h b/llvm/include/llvm/ProfileData/InstrProf.h
index 3a122666200..8fd3d7f8ffd 100644
--- a/llvm/include/llvm/ProfileData/InstrProf.h
+++ b/llvm/include/llvm/ProfileData/InstrProf.h
@@ -513,7 +513,8 @@ typedef struct ValueProfData {
   /// All data in the instance are properly byte swapped. The input
   /// data is assumed to be in little endian order.
   static ErrorOr<std::unique_ptr<ValueProfData>>
-  getValueProfData(const unsigned char *D, const unsigned char *const BufferEnd,
+  getValueProfData(const unsigned char *SrcBuffer,
+                   const unsigned char *const SrcBufferEnd,
                    support::endianness SrcDataEndianness);
   /// Swap byte order from \c Endianness order to host byte order.
   void swapBytesToHost(support::endianness Endianness);
@@ -596,8 +597,8 @@ uint32_t getValueProfDataSizeRT(const ValueProfRuntimeRecord *Record);
 
 /* Return a ValueProfData instance that stores the data collected at runtime. */
 ValueProfData *
-serializeValueProfDataFromRT(const ValueProfRuntimeRecord *Record);
-
+serializeValueProfDataFromRT(const ValueProfRuntimeRecord *Record,
+                             ValueProfData *Dst);
 
 /*! \brief Return the \c ValueProfRecord header size including the
  * padding bytes.
diff --git a/llvm/lib/ProfileData/InstrProf.cpp b/llvm/lib/ProfileData/InstrProf.cpp
index 54c37e30dba..3bbc8249c3d 100644
--- a/llvm/lib/ProfileData/InstrProf.cpp
+++ b/llvm/lib/ProfileData/InstrProf.cpp
@@ -170,10 +170,12 @@ void serializeValueProfRecordFrom(ValueProfRecord *This,
   }
 }
 
-ValueProfData *serializeValueProfDataFrom(ValueProfRecordClosure *Closure) {
+ValueProfData *serializeValueProfDataFrom(ValueProfRecordClosure *Closure,
+                                          ValueProfData *DstData) {
   uint32_t TotalSize = getValueProfDataSize(Closure);
 
-  ValueProfData *VPD = Closure->AllocValueProfData(TotalSize);
+  ValueProfData *VPD =
+      DstData ? DstData : Closure->AllocValueProfData(TotalSize);
 
   VPD->TotalSize = TotalSize;
   VPD->NumValueKinds = Closure->GetNumValueKinds(Closure->Record);
@@ -259,7 +261,7 @@ ValueProfData::serializeFrom(const InstrProfRecord &Record) {
   InstrProfRecordClosure.Record = &Record;
 
   std::unique_ptr<ValueProfData> VPD(
-      serializeValueProfDataFrom(&InstrProfRecordClosure));
+      serializeValueProfDataFrom(&InstrProfRecordClosure, 0));
   return VPD;
 }
 
@@ -367,16 +369,18 @@ uint32_t getValueProfDataSizeRT(const ValueProfRuntimeRecord *Record) {
 }
 
 /* Return a ValueProfData instance that stores the data collected
-   from runtime. */
+ * from runtime. If \c DstData is provided by the caller, the value
+ * profile data will be store in *DstData and DstData is returned,
+ * otherwise the method will allocate space for the value data and
+ * return pointer to the newly allocated space.
+ */
 ValueProfData *
-serializeValueProfDataFromRT(const ValueProfRuntimeRecord *Record) {
+serializeValueProfDataFromRT(const ValueProfRuntimeRecord *Record,
+                             ValueProfData *DstData) {
   RTRecordClosure.Record = Record;
-  return serializeValueProfDataFrom(&RTRecordClosure);
+  return serializeValueProfDataFrom(&RTRecordClosure, DstData);
 }
 
-
-
-
 void ValueProfRecord::deserializeTo(InstrProfRecord &Record,
                                     InstrProfRecord::ValueMapType *VMap) {
   Record.reserveSites(Kind, NumValueSites);
diff --git a/llvm/unittests/ProfileData/InstrProfTest.cpp b/llvm/unittests/ProfileData/InstrProfTest.cpp
index 051bf391b95..d50944ff77f 100644
--- a/llvm/unittests/ProfileData/InstrProfTest.cpp
+++ b/llvm/unittests/ProfileData/InstrProfTest.cpp
@@ -409,7 +409,7 @@ TEST_F(InstrProfTest, runtime_value_prof_data_read_write) {
   initializeValueProfRuntimeRecord(&RTRecord, &NumValueSites[0],
                                    &ValueProfNodes[0]);
 
-  ValueProfData *VPData = serializeValueProfDataFromRT(&RTRecord);
+  ValueProfData *VPData = serializeValueProfDataFromRT(&RTRecord, 0);
 
   InstrProfRecord Record("caller", 0x1234, {1ULL << 31, 2});