[llvm] 14cb0bd - [Attributor][NFC] Replace the nested AAMap with a key pair

[Johannes Doerfert via llvm-commits]

Author: Johannes Doerfert
Date: 2020-05-03T22:10:47-05:00
New Revision: 14cb0bdf2b6ca0b7befbb07fe9f73dad5786f59b

URL: https://github.com/llvm/llvm-project/commit/14cb0bdf2b6ca0b7befbb07fe9f73dad5786f59b
DIFF: https://github.com/llvm/llvm-project/commit/14cb0bdf2b6ca0b7befbb07fe9f73dad5786f59b.diff

LOG: [Attributor][NFC] Replace the nested AAMap with a key pair

No functional change is intended.

---

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

Before:
```
calls to allocation functions: 512375 (362871/s)
temporary memory allocations: 98746 (69933/s)
peak heap memory consumption: 22.54MB
peak RSS (including heaptrack overhead): 106.78MB
total memory leaked: 269.10KB
```

After:
```
calls to allocation functions: 509833 (338534/s)
temporary memory allocations: 98902 (65671/s)
peak heap memory consumption: 18.71MB
peak RSS (including heaptrack overhead): 103.00MB
total memory leaked: 269.10KB
```

Difference:
```
calls to allocation functions: -2542 (-27042/s)
temporary memory allocations: 156 (1659/s)
peak heap memory consumption: -3.83MB
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 6c58e2de3844..42675f89070b 100644
--- a/llvm/include/llvm/Transforms/IPO/Attributor.h
+++ b/llvm/include/llvm/Transforms/IPO/Attributor.h
@@ -885,12 +885,10 @@ struct Attributor {
     // Put the attribute in the lookup map structure and the container we use to
     // keep track of all attributes.
     const IRPosition &IRP = AA.getIRPosition();
-    Kind2AAMapTy *&Kind2AA = AAMap[IRP];
-    if (!Kind2AA)
-      Kind2AA = new (Allocator) Kind2AAMapTy();
+    AbstractAttribute *&AAPtr = AAMap[{&AAType::ID, IRP}];
 
-    assert(!(*Kind2AA)[&AAType::ID] && "Attribute already in map!");
-    (*Kind2AA)[&AAType::ID] = &AA;
+    assert(!AAPtr && "Attribute already in map!");
+    AAPtr = &AA;
 
     AllAbstractAttributes.push_back(&AA);
     return AA;
@@ -1278,13 +1276,11 @@ struct Attributor {
 
     // Lookup the abstract attribute of type AAType. If found, return it after
     // registering a dependence of QueryingAA on the one returned attribute.
-    Kind2AAMapTy *Kind2AA = AAMap.lookup(IRP);
-    if (!Kind2AA)
+    AbstractAttribute *AAPtr = AAMap.lookup({&AAType::ID, IRP});
+    if (!AAPtr)
       return nullptr;
 
-    AAType *AA = static_cast<AAType *>((*Kind2AA)[&AAType::ID]);
-    if (!AA)
-      return nullptr;
+    AAType *AA = static_cast<AAType *>(AAPtr);
 
     // Do not register a dependence on an attribute with an invalid state.
     if (TrackDependence && AA->getState().isValidState())
@@ -1309,9 +1305,8 @@ struct Attributor {
   /// on the outer level, and the addresses of the static member (AAType::ID) on
   /// the inner level.
   ///{
-  using Kind2AAMapTy =
-      SmallDenseMap<const char *, AbstractAttribute *, /*InlineBuckets=*/32>;
-  DenseMap<IRPosition, Kind2AAMapTy *> AAMap;
+  using AAMapKeyTy = std::pair<const char *, IRPosition>;
+  DenseMap<AAMapKeyTy, AbstractAttribute *> AAMap;
   ///}
 
   /// A map from abstract attributes to the ones that queried them through calls

diff  --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
index b8602538076b..71595a8e2341 100644
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -493,11 +493,6 @@ Attributor::~Attributor() {
   for (AbstractAttribute *AA : AllAbstractAttributes)
     AA->~AbstractAttribute();
 
-  // The Kind2AAMap objects are allocated via a BumpPtrAllocator, we call
-  // the destructor manually.
-  for (auto &It : AAMap)
-    It.getSecond()->~Kind2AAMapTy();
-
   // The QueryMapValueTy objects are allocated via a BumpPtrAllocator, we call
   // the destructor manually.
   for (auto &It : QueryMap)