[Polly] Ensure consistent Scop::InstStmtMap. NFC.

InstStmtMap became inconsistent with ScopStmt::getInstructions() after
the statement's instructions is modified, e.g. by being considered
unused by the Simplify pass or being moved by ForwardOpTree.

Change ScopStmt::setInstructions() to also update its parent's
InstStmtMap. Also add assertions checking the consistency.

1 files changed, 8 insertions, 4 deletions

diff --git a/polly/include/polly/ScopInfo.h b/polly/include/polly/ScopInfo.h
index b6fcddc6379a..7b6f13627826 100644
--- a/polly/include/polly/ScopInfo.h
+++ b/polly/include/polly/ScopInfo.h
@@ -1539,9 +1539,7 @@ public:
 
   /// Set the list of instructions for this statement. It replaces the current
   /// list.
-  void setInstructions(ArrayRef<Instruction *> Range) {
-    Instructions.assign(Range.begin(), Range.end());
-  }
+  void setInstructions(ArrayRef<Instruction *> Range);
 
   std::vector<Instruction *>::const_iterator insts_begin() const {
     return Instructions.begin();
@@ -1949,7 +1947,7 @@ private:
   void addScopStmt(Region *R, StringRef Name, Loop *SurroundingLoop,
                    std::vector<Instruction *> EntryBlockInstructions);
 
-  /// Removes @p Stmt from the StmtMap.
+  /// Removes @p Stmt from the StmtMap and InstStmtMap.
   void removeFromStmtMap(ScopStmt &Stmt);
 
   /// Removes all statements where the entry block of the statement does not
@@ -2362,6 +2360,12 @@ public:
     return InstStmtMap.lookup(Inst);
   }
 
+  /// Update the content of InstStmtMap for @p Stmt. @p OldList contains the
+  /// previous instructions in @p Stmt and is updated to contain the
+  /// instructions in @p NewList.
+  void updateInstStmtMap(ArrayRef<Instruction *> OldList,
+                         ArrayRef<Instruction *> NewList, ScopStmt *Stmt);
+
   /// Return the number of statements in the SCoP.
   size_t getSize() const { return Stmts.size(); }