[llvm-branch-commits] [llvm] f8afba5 - [AA] Add statistics for alias results (NFC)

[Nikita Popov via llvm-branch-commits]

Author: Nikita Popov
Date: 2020-12-05T11:09:15+01:00
New Revision: f8afba5f7a25a69c12191d979d78d40fa6e5b684

URL: https://github.com/llvm/llvm-project/commit/f8afba5f7a25a69c12191d979d78d40fa6e5b684
DIFF: https://github.com/llvm/llvm-project/commit/f8afba5f7a25a69c12191d979d78d40fa6e5b684.diff

LOG: [AA] Add statistics for alias results (NFC)

Count how many NoAlias/MustAlias/MayAlias we get from top-level
queries.

Added: 
    

Modified: 
    llvm/include/llvm/Analysis/AliasAnalysis.h
    llvm/lib/Analysis/AliasAnalysis.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/Analysis/AliasAnalysis.h b/llvm/include/llvm/Analysis/AliasAnalysis.h
index 7a4338905129..05c01931766e 100644
--- a/llvm/include/llvm/Analysis/AliasAnalysis.h
+++ b/llvm/include/llvm/Analysis/AliasAnalysis.h
@@ -814,6 +814,9 @@ class AAResults {
 
   std::vector<AnalysisKey *> AADeps;
 
+  /// Query depth used to distinguish recursive queries.
+  unsigned Depth;
+
   friend class BatchAAResults;
 };
 

diff  --git a/llvm/lib/Analysis/AliasAnalysis.cpp b/llvm/lib/Analysis/AliasAnalysis.cpp
index 3d094a65a5e3..6635e5302e36 100644
--- a/llvm/lib/Analysis/AliasAnalysis.cpp
+++ b/llvm/lib/Analysis/AliasAnalysis.cpp
@@ -24,6 +24,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/BasicAliasAnalysis.h"
 #include "llvm/Analysis/CFLAndersAliasAnalysis.h"
 #include "llvm/Analysis/CFLSteensAliasAnalysis.h"
@@ -54,8 +55,14 @@
 #include <functional>
 #include <iterator>
 
+#define DEBUG_TYPE "aa"
+
 using namespace llvm;
 
+STATISTIC(NumNoAlias,   "Number of NoAlias results");
+STATISTIC(NumMayAlias,  "Number of MayAlias results");
+STATISTIC(NumMustAlias, "Number of MustAlias results");
+
 /// Allow disabling BasicAA from the AA results. This is particularly useful
 /// when testing to isolate a single AA implementation.
 cl::opt<bool> DisableBasicAA("disable-basic-aa", cl::Hidden, cl::init(false));
@@ -109,12 +116,25 @@ AliasResult AAResults::alias(const MemoryLocation &LocA,
 
 AliasResult AAResults::alias(const MemoryLocation &LocA,
                              const MemoryLocation &LocB, AAQueryInfo &AAQI) {
+  AliasResult Result = MayAlias;
+
+  Depth++;
   for (const auto &AA : AAs) {
-    auto Result = AA->alias(LocA, LocB, AAQI);
+    Result = AA->alias(LocA, LocB, AAQI);
     if (Result != MayAlias)
-      return Result;
+      break;
+  }
+  Depth--;
+
+  if (Depth == 0) {
+    if (Result == NoAlias)
+      ++NumNoAlias;
+    else if (Result == MustAlias)
+      ++NumMustAlias;
+    else
+      ++NumMayAlias;
   }
-  return MayAlias;
+  return Result;
 }
 
 bool AAResults::pointsToConstantMemory(const MemoryLocation &Loc,