[ScopInfo] Introduce list of statements in Scop::StmtMap. NFC.

Once statements are split, a BasicBlock will comprise of multiple
statements. To prepare for this change in future, we introduce a list
of statements in the statement map.

Contributed-by: Nandini Singhal <cs15mtech01004@iith.ac.in>

Differential Revision: https://reviews.llvm.org/D35301

llvm-svn: 308318

2 files changed, 7 insertions, 5 deletions

diff --git a/polly/include/polly/ScopInfo.h b/polly/include/polly/ScopInfo.h
index edf40d6b..27f79ba 100644
--- a/polly/include/polly/ScopInfo.h
+++ b/polly/include/polly/ScopInfo.h
@@ -1670,8 +1670,9 @@ private:
   /// delete the last object that creates isl objects with the context.
   std::shared_ptr<isl_ctx> IslCtx;
 
-  /// A map from basic blocks to SCoP statements.
-  DenseMap<BasicBlock *, ScopStmt *> StmtMap;
+  /// A map from basic blocks to vector of SCoP statements. Currently this
+  /// vector comprises only of a single statement.
+  DenseMap<BasicBlock *, std::vector<ScopStmt *>> StmtMap;
 
   /// A map from basic blocks to their domains.
   DenseMap<BasicBlock *, isl::set> DomainMap;
diff --git a/polly/lib/Analysis/ScopInfo.cpp b/polly/lib/Analysis/ScopInfo.cpp
index 0f23526..d0247e8 100644
--- a/polly/lib/Analysis/ScopInfo.cpp
+++ b/polly/lib/Analysis/ScopInfo.cpp
@@ -4748,7 +4748,7 @@ void Scop::addScopStmt(BasicBlock *BB, Loop *SurroundingLoop,
   assert(BB && "Unexpected nullptr!");
   Stmts.emplace_back(*this, *BB, SurroundingLoop, Instructions);
   auto *Stmt = &Stmts.back();
-  StmtMap[BB] = Stmt;
+  StmtMap[BB].push_back(Stmt);
 }
 
 void Scop::addScopStmt(Region *R, Loop *SurroundingLoop) {
@@ -4756,7 +4756,7 @@ void Scop::addScopStmt(Region *R, Loop *SurroundingLoop) {
   Stmts.emplace_back(*this, *R, SurroundingLoop);
   auto *Stmt = &Stmts.back();
   for (BasicBlock *BB : R->blocks())
-    StmtMap[BB] = Stmt;
+    StmtMap[BB].push_back(Stmt);
 }
 
 ScopStmt *Scop::addScopStmt(__isl_take isl_map *SourceRel,
@@ -4908,7 +4908,8 @@ ScopStmt *Scop::getStmtFor(BasicBlock *BB) const {
   auto StmtMapIt = StmtMap.find(BB);
   if (StmtMapIt == StmtMap.end())
     return nullptr;
-  return StmtMapIt->second;
+  assert(StmtMapIt->second.size() == 1);
+  return StmtMapIt->second.front();
 }
 
 ScopStmt *Scop::getStmtFor(RegionNode *RN) const {