commit ac3d6caa0f5c96c9d6003c243d61818b9c0a26c0
author Michael Kruse <llvm-project@meinersbur.de> Fri Aug 13 12:26:35 2021 -0500
committer Copybara-Service <copybara-worker@google.com> Fri Aug 13 10:50:44 2021 -0700
tree da477a543eef2b2b016507d9ce1e81362e7484ef
parent 6a37add8b41befff0d1a7a2c0ebc93e13ece2371

[Polly] Decompose object construction and detection algorithm. NFC.

Avoid doing the detection work inside the constructor. In addition to
polymorphism being unintuitive in constructors and other design problems
such as if an exception is thrown, the ScopDetection class is usable
without detection in the sense of "no Scop found" or "function skipped".

GitOrigin-RevId: 0232c1d10dd79f5c8f9530d636655488eb3c9e7e

include/polly/ScopDetection.h

diff --git a/include/polly/ScopDetection.h b/include/polly/ScopDetection.h
index 86a3a8e..df9e275 100644
--- a/include/polly/ScopDetection.h
+++ b/include/polly/ScopDetection.h
@@ -497,7 +497,7 @@
   /// Check if the function @p F is marked as invalid.
   ///
   /// @note An OpenMP subfunction will be marked as invalid.
-  bool isValidFunction(Function &F);
+  static bool isValidFunction(Function &F);
 
   /// Can ISL compute the trip count of a loop.
   ///
@@ -529,9 +529,10 @@
                       Args &&...Arguments) const;
 
 public:
-  ScopDetection(Function &F, const DominatorTree &DT, ScalarEvolution &SE,
-                LoopInfo &LI, RegionInfo &RI, AAResults &AA,
-                OptimizationRemarkEmitter &ORE);
+  ScopDetection(const DominatorTree &DT, ScalarEvolution &SE, LoopInfo &LI,
+                RegionInfo &RI, AAResults &AA, OptimizationRemarkEmitter &ORE);
+
+  void detect(Function &F);
 
   /// Get the RegionInfo stored in this pass.
   ///

lib/Analysis/ScopDetection.cpp

diff --git a/lib/Analysis/ScopDetection.cpp b/lib/Analysis/ScopDetection.cpp
index 2d7c1c3..65694b7 100644
--- a/lib/Analysis/ScopDetection.cpp
+++ b/lib/Analysis/ScopDetection.cpp
@@ -333,10 +333,14 @@
 //===----------------------------------------------------------------------===//
 // ScopDetection.
 
-ScopDetection::ScopDetection(Function &F, const DominatorTree &DT,
-                             ScalarEvolution &SE, LoopInfo &LI, RegionInfo &RI,
-                             AliasAnalysis &AA, OptimizationRemarkEmitter &ORE)
-    : DT(DT), SE(SE), LI(LI), RI(RI), AA(AA), ORE(ORE) {
+ScopDetection::ScopDetection(const DominatorTree &DT, ScalarEvolution &SE,
+                             LoopInfo &LI, RegionInfo &RI, AliasAnalysis &AA,
+                             OptimizationRemarkEmitter &ORE)
+    : DT(DT), SE(SE), LI(LI), RI(RI), AA(AA), ORE(ORE) {}
+
+void ScopDetection::detect(Function &F) {
+  assert(ValidRegions.empty() && "Detection must run only once");
+
   if (!PollyProcessUnprofitable && LI.empty())
     return;
 
@@ -1875,7 +1879,9 @@
   auto &SE = getAnalysis<ScalarEvolutionWrapperPass>().getSE();
   auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
   auto &ORE = getAnalysis<OptimizationRemarkEmitterWrapperPass>().getORE();
-  Result.reset(new ScopDetection(F, DT, SE, LI, RI, AA, ORE));
+
+  Result = std::make_unique<ScopDetection>(DT, SE, LI, RI, AA, ORE);
+  Result->detect(F);
   return false;
 }
 
@@ -1922,7 +1928,10 @@
   auto &SE = FAM.getResult<ScalarEvolutionAnalysis>(F);
   auto &DT = FAM.getResult<DominatorTreeAnalysis>(F);
   auto &ORE = FAM.getResult<OptimizationRemarkEmitterAnalysis>(F);
-  return {F, DT, SE, LI, RI, AA, ORE};
+
+  ScopDetection Result(DT, SE, LI, RI, AA, ORE);
+  Result.detect(F);
+  return Result;
 }
 
 PreservedAnalyses ScopAnalysisPrinterPass::run(Function &F,