llvm-profdata: Indirect infrequently used fields to reduce memory usage

Examining a large profile example, it seems relatively few records have
non-empty IndirectCall and MemOP data, so indirecting these through a
unique_ptr (non-null only when they are non-empty) Reduces memory usage
on this particular example from 14GB to 10GB according to valgrind's
massif.

I suspect it'd still be worth moving InstrProfWriter to its own data
structure that had Counts and the indirected IndirectCall+MemOP, and did
not include the Name, Hash, or Error fields. This would reduce the size
of this dominant data structure by half of this new, lower amount.
(Name(2), Hash(1), Error(1) ~= Counts(vector, 3), ValueProfData
(unique_ptr, 1))
-> From code review feedback, might actually refactor InstrProfRecord
itself to have a sub-struct with all the counts, and use that from
InstrProfWriter, rather than InstrProfWriter owning its own data
structure for this.

Reviewers: davidxl

Differential Revision: https://reviews.llvm.org/D34694

llvm-svn: 306631

1 files changed, 7 insertions, 8 deletions

diff --git a/llvm/lib/ProfileData/InstrProf.cpp b/llvm/lib/ProfileData/InstrProf.cpp
index 1dc596fa7ed..a1d18724fcd 100644
--- a/llvm/lib/ProfileData/InstrProf.cpp
+++ b/llvm/lib/ProfileData/InstrProf.cpp
@@ -504,9 +504,11 @@ void InstrProfRecord::mergeValueProfData(uint32_t ValueKind,
     SIPE.addError(instrprof_error::value_site_count_mismatch);
     return;
   }
+  if (!ThisNumValueSites)
+    return;
   std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
-      getValueSitesForKind(ValueKind);
-  std::vector<InstrProfValueSiteRecord> &OtherSiteRecords =
+      getOrCreateValueSitesForKind(ValueKind);
+  MutableArrayRef<InstrProfValueSiteRecord> OtherSiteRecords =
       Src.getValueSitesForKind(ValueKind);
   for (uint32_t I = 0; I < ThisNumValueSites; I++)
     ThisSiteRecords[I].merge(SIPE, OtherSiteRecords[I], Weight);
@@ -533,11 +535,8 @@ void InstrProfRecord::merge(InstrProfRecord &Other, uint64_t Weight) {
 }
 
 void InstrProfRecord::scaleValueProfData(uint32_t ValueKind, uint64_t Weight) {
-  uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
-  std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
-      getValueSitesForKind(ValueKind);
-  for (uint32_t I = 0; I < ThisNumValueSites; I++)
-    ThisSiteRecords[I].scale(SIPE, Weight);
+  for (auto &R : getValueSitesForKind(ValueKind))
+    R.scale(SIPE, Weight);
 }
 
 void InstrProfRecord::scale(uint64_t Weight) {
@@ -583,7 +582,7 @@ void InstrProfRecord::addValueData(uint32_t ValueKind, uint32_t Site,
     VData[I].Value = remapValue(VData[I].Value, ValueKind, ValueMap);
   }
   std::vector<InstrProfValueSiteRecord> &ValueSites =
-      getValueSitesForKind(ValueKind);
+      getOrCreateValueSitesForKind(ValueKind);
   if (N == 0)
     ValueSites.emplace_back();
   else