commit 51dc04cff25c5f9ab97dfa88fdd81566302fd349
author Xinliang David Li <davidxl@google.com> Fri Jan 08 03:49:59 2016 +0000
committer Xinliang David Li <davidxl@google.com> Fri Jan 08 03:49:59 2016 +0000
tree 9df0beb2024c9f6ea7d69ea44a152797045d7869
parent 652b97bcf7eb2c7d0ac118401581ff131051b65d

[PGO] Fix a bug in InstProfWriter addRecord

For a new record with weight != 1, only edge profiling
counters are scaled, VP data is not properly scaled.

This patch refactors the code and fixes the problem.
Also added sort by count interface (for follow up patch).

llvm-svn: 257143

llvm/lib/ProfileData/InstrProf.cpp

diff --git a/llvm/lib/ProfileData/InstrProf.cpp b/llvm/lib/ProfileData/InstrProf.cpp
index 027f0f7..94c701d 100644
--- a/llvm/lib/ProfileData/InstrProf.cpp
+++ b/llvm/lib/ProfileData/InstrProf.cpp
@@ -257,9 +257,8 @@
   return 0;
 }
 
-instrprof_error
-InstrProfValueSiteRecord::mergeValueData(InstrProfValueSiteRecord &Input,
-                                         uint64_t Weight) {
+instrprof_error InstrProfValueSiteRecord::merge(InstrProfValueSiteRecord &Input,
+                                                uint64_t Weight) {
   this->sortByTargetValues();
   Input.sortByTargetValues();
   auto I = ValueData.begin();
@@ -288,6 +287,17 @@
   return Result;
 }
 
+instrprof_error InstrProfValueSiteRecord::scale(uint64_t Weight) {
+  instrprof_error Result = instrprof_error::success;
+  for (auto I = ValueData.begin(), IE = ValueData.end(); I != IE; ++I) {
+    bool Overflowed;
+    I->Count = SaturatingMultiply(I->Count, Weight, &Overflowed);
+    if (Overflowed)
+      Result = instrprof_error::counter_overflow;
+  }
+  return Result;
+}
+
 // Merge Value Profile data from Src record to this record for ValueKind.
 // Scale merged value counts by \p Weight.
 instrprof_error InstrProfRecord::mergeValueProfData(uint32_t ValueKind,
@@ -303,8 +313,7 @@
       Src.getValueSitesForKind(ValueKind);
   instrprof_error Result = instrprof_error::success;
   for (uint32_t I = 0; I < ThisNumValueSites; I++)
-    MergeResult(Result,
-                ThisSiteRecords[I].mergeValueData(OtherSiteRecords[I], Weight));
+    MergeResult(Result, ThisSiteRecords[I].merge(OtherSiteRecords[I], Weight));
   return Result;
 }
 
@@ -336,6 +345,32 @@
   return Result;
 }
 
+instrprof_error InstrProfRecord::scaleValueProfData(uint32_t ValueKind,
+                                                    uint64_t Weight) {
+  uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
+  std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
+      getValueSitesForKind(ValueKind);
+  instrprof_error Result = instrprof_error::success;
+  for (uint32_t I = 0; I < ThisNumValueSites; I++)
+    MergeResult(Result, ThisSiteRecords[I].scale(Weight));
+  return Result;
+}
+
+instrprof_error InstrProfRecord::scale(uint64_t Weight) {
+  instrprof_error Result = instrprof_error::success;
+  for (auto &Count : this->Counts) {
+    bool Overflowed;
+    Count = SaturatingMultiply(Count, Weight, &Overflowed);
+    if (Overflowed && Result == instrprof_error::success) {
+      Result = instrprof_error::counter_overflow;
+    }
+  }
+  for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
+    MergeResult(Result, scaleValueProfData(Kind, Weight));
+
+  return Result;
+}
+
 // Map indirect call target name hash to name string.
 uint64_t InstrProfRecord::remapValue(uint64_t Value, uint32_t ValueKind,
                                      ValueMapType *ValueMap) {