add comments to address review and remove more prints

Author: adhithadias

include/taco/index_notation/index_notation.h

@@ -648,6 +648,13 @@ class IndexStmt : public util::IntrusivePtr<const IndexStmtNode> {
 
   /// The loopfuse transformation fuses common outer loops in 
   /// 2 iteration graphs. 
+  /// when performing loopfuse operation on an already branched index statement
+  /// eg: forall(l, where(forall(ijk, T(j,k) += A*B), forall(mjkn, X(l,m,n) += T*C*D)))
+  /// and we want to further breakdown T*C*D into T2 = T*C and T2*D
+  /// we can use the path vector to specify the branch we want to apply the fuse on
+  /// eg: loopfuse(2, true, {1}) where 2 refers to breaking T*C*D at the 2nd position
+  /// and true refers to making T*C as the producer (if false, then C*D will be the producer if used with 1)
+  /// and {1} refers to the branch we want to apply the fuse on
   IndexStmt loopfuse(int pos, bool isProducerOnLeft, std::vector<int>& path) const;
 
 

include/taco/parser/lexer.h

@@ -22,7 +22,7 @@ enum class Token {
   sub,
   mul,
   div,
-  colon,
+  colon, // numbers before the colon indicate the path to branch in a branched iteration graph
   eq,
   eot,  // End of tokens
   error

src/index_notation/index_notation.cpp

@@ -1855,15 +1855,7 @@ IndexStmt IndexStmt::divide(IndexVar i, IndexVar i1, IndexVar i2, size_t splitFa
 }
 
 IndexStmt IndexStmt::loopfuse(int pos, bool isProducerOnLeft, vector<int>& path) const {
-
-  std::cout << "Loop fuse pos: " << pos;
-  std::cout << ", Loop fuse isProducerOnLeft: " << isProducerOnLeft;
-  for (const auto& p : path) {
-    std::cout << " " << p;
-  }
-  std::cout << std::endl;
-
-  string reason;
+  string reason; // reason saves the error message if the transformation fails
   IndexStmt transformed = *this;
   transformed = Transformation(LoopFuse(pos, isProducerOnLeft, path)).apply(transformed, &reason);
   if (!transformed.defined()) {
@@ -1929,8 +1921,6 @@ IndexStmt IndexStmt::reorder(std::vector<IndexVar> reorderedvars) const {
 
 IndexStmt IndexStmt::reorder(std::vector<int> path, std::vector<IndexVar> reorderedvars) const {
   string reason;
-  cout << "Index statement path: " << util::join(path) << endl;
-  cout << "Index statement reorderedvars: " << reorderedvars << endl;
   IndexStmt transformed = Reorder(path, reorderedvars).apply(*this, &reason);
   if (!transformed.defined()) {
     taco_uerror << reason;