[llvm] 87aa362 - [Attributor] Use the BumpPtrAllocator in InformationCache as well

[Johannes Doerfert via llvm-commits]

Author: Johannes Doerfert
Date: 2020-04-20T21:12:41-05:00
New Revision: 87aa3629856adfd8529a57889c240567b7f5bf13

URL: https://github.com/llvm/llvm-project/commit/87aa3629856adfd8529a57889c240567b7f5bf13
DIFF: https://github.com/llvm/llvm-project/commit/87aa3629856adfd8529a57889c240567b7f5bf13.diff

LOG: [Attributor] Use the BumpPtrAllocator in InformationCache as well

We now also use the BumpPtrAllocator from the Attributor in the
InformationCache. The lifetime of objects in either is pretty much the
same and it should result in consistently good performance regardless of
the allocator.

Doing so requires to call more constructors manually but so far that
does not seem to be problematic or messy.

---

Single run of the Attributor module and then CGSCC pass (oldPM)
for SPASS/clause.c (~10k LLVM-IR loc):

Before:
```
calls to allocation functions: 615359 (368257/s)
temporary memory allocations: 83315 (49859/s)
peak heap memory consumption: 75.64MB
peak RSS (including heaptrack overhead): 163.43MB
total memory leaked: 269.04KB
```

After:
```
calls to allocation functions: 613042 (359555/s)
temporary memory allocations: 83322 (48869/s)
peak heap memory consumption: 75.64MB
peak RSS (including heaptrack overhead): 162.92MB
total memory leaked: 269.04KB
```

Difference:
```
calls to allocation functions: -2317 (-68147/s)
temporary memory allocations: 7 (205/s)
peak heap memory consumption: 2.23KB
peak RSS (including heaptrack overhead): 0B
total memory leaked: 0B

---

Added: 
    

Modified: 
    llvm/include/llvm/Transforms/IPO/Attributor.h
    llvm/lib/Transforms/IPO/Attributor.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/Transforms/IPO/Attributor.h b/llvm/include/llvm/Transforms/IPO/Attributor.h
index 99989775bde6..f242b9329799 100644
--- a/llvm/include/llvm/Transforms/IPO/Attributor.h
+++ b/llvm/include/llvm/Transforms/IPO/Attributor.h
@@ -549,8 +549,8 @@ struct AnalysisGetter {
 /// instance down in the abstract attributes.
 struct InformationCache {
   InformationCache(const Module &M, AnalysisGetter &AG,
-                   SetVector<Function *> *CGSCC)
-      : DL(M.getDataLayout()),
+                   BumpPtrAllocator &Allocator, SetVector<Function *> *CGSCC)
+      : DL(M.getDataLayout()), Allocator(Allocator),
         Explorer(
             /* ExploreInterBlock */ true, /* ExploreCFGForward */ true,
             /* ExploreCFGBackward */ true,
@@ -567,7 +567,10 @@ struct InformationCache {
         AG(AG), CGSCC(CGSCC) {}
 
   ~InformationCache() {
-    DeleteContainerSeconds(FuncInfoMap);
+    // The FunctionInfo objects are allocated via a BumpPtrAllocator, we call
+    // the destructor manually.
+    for (auto &It : FuncInfoMap)
+      It.getSecond()->~FunctionInfo();
   }
 
   /// A map type from opcodes to instructions with this opcode.
@@ -652,7 +655,7 @@ struct InformationCache {
   FunctionInfo &getFunctionInfo(const Function &F) {
     FunctionInfo *&FI = FuncInfoMap[&F];
     if (!FI) {
-      FI = new FunctionInfo();
+      FI = new (Allocator) FunctionInfo();
       initializeInformationCache(F, *FI);
     }
     return *FI;
@@ -667,6 +670,9 @@ struct InformationCache {
   /// The datalayout used in the module.
   const DataLayout &DL;
 
+  /// The allocator used to allocate memory, e.g. for `FunctionInfo`s.
+  BumpPtrAllocator &Allocator;
+
   /// MustBeExecutedContextExplorer
   MustBeExecutedContextExplorer Explorer;
 
@@ -727,7 +733,8 @@ struct Attributor {
   Attributor(SetVector<Function *> &Functions, InformationCache &InfoCache,
              CallGraphUpdater &CGUpdater, unsigned DepRecomputeInterval,
              DenseSet<const char *> *Whitelist = nullptr)
-      : Functions(Functions), InfoCache(InfoCache), CGUpdater(CGUpdater),
+      : Allocator(InfoCache.Allocator), Functions(Functions),
+        InfoCache(InfoCache), CGUpdater(CGUpdater),
         DepRecomputeInterval(DepRecomputeInterval), Whitelist(Whitelist) {}
 
   ~Attributor();
@@ -1100,7 +1107,7 @@ struct Attributor {
   const DataLayout &getDataLayout() const { return InfoCache.DL; }
 
   /// The allocator used to allocate memory, e.g. for `AbstractAttribute`s.
-  BumpPtrAllocator Allocator;
+  BumpPtrAllocator &Allocator;
 
 private:
   /// Check \p Pred on all call sites of \p Fn.

diff  --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
index bf2e0c3c864b..2d92423106fa 100644
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -2010,7 +2010,8 @@ PreservedAnalyses AttributorPass::run(Module &M, ModuleAnalysisManager &AM) {
     Functions.insert(&F);
 
   CallGraphUpdater CGUpdater;
-  InformationCache InfoCache(M, AG, /* CGSCC */ nullptr);
+  BumpPtrAllocator Allocator;
+  InformationCache InfoCache(M, AG, Allocator, /* CGSCC */ nullptr);
   if (runAttributorOnFunctions(InfoCache, Functions, AG, CGUpdater)) {
     // FIXME: Think about passes we will preserve and add them here.
     return PreservedAnalyses::none();
@@ -2036,7 +2037,8 @@ PreservedAnalyses AttributorCGSCCPass::run(LazyCallGraph::SCC &C,
   Module &M = *Functions.back()->getParent();
   CallGraphUpdater CGUpdater;
   CGUpdater.initialize(CG, C, AM, UR);
-  InformationCache InfoCache(M, AG, /* CGSCC */ &Functions);
+  BumpPtrAllocator Allocator;
+  InformationCache InfoCache(M, AG, Allocator, /* CGSCC */ &Functions);
   if (runAttributorOnFunctions(InfoCache, Functions, AG, CGUpdater)) {
     // FIXME: Think about passes we will preserve and add them here.
     return PreservedAnalyses::none();
@@ -2063,7 +2065,8 @@ struct AttributorLegacyPass : public ModulePass {
       Functions.insert(&F);
 
     CallGraphUpdater CGUpdater;
-    InformationCache InfoCache(M, AG, /* CGSCC */ nullptr);
+    BumpPtrAllocator Allocator;
+    InformationCache InfoCache(M, AG, Allocator, /* CGSCC */ nullptr);
     return runAttributorOnFunctions(InfoCache, Functions, AG, CGUpdater);
   }
 
@@ -2098,7 +2101,8 @@ struct AttributorCGSCCLegacyPass : public CallGraphSCCPass {
     CallGraph &CG = const_cast<CallGraph &>(SCC.getCallGraph());
     CGUpdater.initialize(CG, SCC);
     Module &M = *Functions.back()->getParent();
-    InformationCache InfoCache(M, AG, /* CGSCC */ &Functions);
+    BumpPtrAllocator Allocator;
+    InformationCache InfoCache(M, AG, Allocator, /* CGSCC */ &Functions);
     return runAttributorOnFunctions(InfoCache, Functions, AG, CGUpdater);
   }