Remove PurifyRVar split type.

src/ApplySplit.cpp

@@ -157,7 +157,6 @@ vector<ApplySplitResult> apply_split(const Split &split, const string &prefix,
         }
     } break;
     case Split::RenameVar:
-    case Split::PurifyRVar:
         result.emplace_back(prefix + split.old_var, outer, ApplySplitResult::Substitution);
         result.emplace_back(prefix + split.old_var, outer, ApplySplitResult::LetStmt);
         break;
@@ -201,9 +200,6 @@ vector<std::pair<string, Expr>> compute_loop_bounds_after_split(const Split &spl
         let_stmts.emplace_back(prefix + split.outer + ".loop_max", old_var_max);
         let_stmts.emplace_back(prefix + split.outer + ".loop_extent", old_var_extent);
         break;
-    case Split::PurifyRVar:
-        // Do nothing for purify
-        break;
     }
 
     return let_stmts;

src/Deserialization.cpp

@@ -368,8 +368,6 @@ Split::SplitType Deserializer::deserialize_split_type(Serialize::SplitType split
         return Split::SplitType::RenameVar;
     case Serialize::SplitType::FuseVars:
         return Split::SplitType::FuseVars;
-    case Serialize::SplitType::PurifyRVar:
-        return Split::SplitType::PurifyRVar;
     default:
         user_error << "unknown split type " << (int)split_type << "\n";
         return Split::SplitType::SplitVar;

src/Func.cpp

@@ -431,7 +431,6 @@ void check_for_race_conditions_in_split_with_blend(const StageSchedule &sched) {
             }
             break;
         case Split::RenameVar:
-        case Split::PurifyRVar:
             if (parallel.count(split.outer)) {
                 parallel.insert(split.old_var);
             }
@@ -454,7 +453,6 @@ void check_for_race_conditions_in_split_with_blend(const StageSchedule &sched) {
             }
             break;
         case Split::RenameVar:
-        case Split::PurifyRVar:
             if (parallel.count(split.old_var)) {
                 parallel.insert(split.outer);
             }
@@ -793,7 +791,6 @@ pair<vector<Split>, vector<Split>> Stage::rfactor_validate_args(const std::vecto
                 var_splits.emplace_back(split);
             }
             break;
-        case Split::PurifyRVar:
         case Split::RenameVar:
             if (rdims.contains(split.old_var)) {
                 rdims.pop(split.old_var);
@@ -1068,7 +1065,6 @@ void Stage::split(const string &old, const string &outer, const string &inner, c
                 }
                 break;
             case Split::RenameVar:
-            case Split::PurifyRVar:
                 if (inner_vars.count(s.old_var)) {
                     inner_vars.insert(s.outer);
                 }
@@ -1103,7 +1099,6 @@ void Stage::split(const string &old, const string &outer, const string &inner, c
                 }
                 break;
             case Split::RenameVar:
-            case Split::PurifyRVar:
                 if (inner_vars.count(s.old_var)) {
                     inner_vars.insert(s.outer);
                 }
@@ -1165,7 +1160,6 @@ void Stage::split(const string &old, const string &outer, const string &inner, c
                     }
                     break;
                 case Split::RenameVar:
-                case Split::PurifyRVar:
                     if (it != descends_from_shiftinwards_outer.end()) {
                         descends_from_shiftinwards_outer[s.outer] = it->second;
                     }
@@ -1352,46 +1346,6 @@ void Stage::specialize_fail(const std::string &message) {
     s.failure_message = message;
 }
 
-Stage &Stage::purify(const VarOrRVar &old_var, const VarOrRVar &new_var) {
-    user_assert(old_var.is_rvar && !new_var.is_rvar)
-        << "In schedule for " << name()
-        << ", can't rename " << (old_var.is_rvar ? "RVar " : "Var ") << old_var.name()
-        << " to " << (new_var.is_rvar ? "RVar " : "Var ") << new_var.name()
-        << "; purify must take a RVar as old_Var and a Var as new_var\n";
-
-    debug(4) << "In schedule for " << name() << ", purify RVar "
-             << old_var.name() << " to Var " << new_var.name() << "\n";
-
-    StageSchedule &schedule = definition.schedule();
-
-    // Replace the old dimension with the new dimensions in the dims list
-    bool found = false;
-    string old_name, new_name = new_var.name();
-    vector<Dim> &dims = schedule.dims();
-
-    for (size_t i = 0; (!found) && i < dims.size(); i++) {
-        if (dim_match(dims[i], old_var)) {
-            found = true;
-            old_name = dims[i].var;
-            dims[i].var = new_name;
-            dims[i].dim_type = DimType::PureVar;
-        }
-    }
-
-    if (!found) {
-        user_error
-            << "In schedule for " << name()
-            << ", could not find rename dimension: "
-            << old_var.name()
-            << "\n"
-            << dump_argument_list();
-    }
-
-    Split split = {old_name, new_name, "", 1, false, TailStrategy::RoundUp, Split::PurifyRVar};
-    definition.schedule().splits().push_back(split);
-    return *this;
-}
-
 void Stage::remove(const string &var) {
     debug(4) << "In schedule for " << name() << ", remove " << var << "\n";
 
@@ -1469,7 +1423,6 @@ void Stage::remove(const string &var) {
             }
             break;
         case Split::RenameVar:
-        case Split::PurifyRVar:
             debug(4) << "    replace/rename " << split.old_var
                      << " into " << split.outer << "\n";
             if (should_remove(split.outer)) {
@@ -1558,7 +1511,6 @@ Stage &Stage::rename(const VarOrRVar &old_var, const VarOrRVar &new_var) {
             break;
         case Split::SplitVar:
         case Split::RenameVar:
-        case Split::PurifyRVar:
             if (split.inner == old_name) {
                 split.inner = new_name;
                 found = true;

src/Func.h

@@ -82,7 +82,6 @@ class Stage {
     void split(const std::string &old, const std::string &outer, const std::string &inner,
                const Expr &factor, bool exact, TailStrategy tail);
     void remove(const std::string &var);
-    Stage &purify(const VarOrRVar &old_name, const VarOrRVar &new_name);
 
     const std::vector<Internal::StorageDim> &storage_dims() const {
         return function.schedule().storage_dims();

src/Inline.cpp

@@ -76,8 +76,6 @@ void validate_schedule_inlined_function(Function f) {
                          << split.inner << " because "
                          << f.name() << " is scheduled inline.\n";
 
-            break;
-        case Split::PurifyRVar:
             break;
         }
     }

src/Schedule.h

@@ -332,19 +332,14 @@ struct Split {
 
     enum SplitType { SplitVar = 0,
                      RenameVar,
-                     FuseVars,
-                     PurifyRVar };
+                     FuseVars };
 
     // If split_type is Rename, then this is just a renaming of the
     // old_var to the outer and not a split. The inner var should
     // be ignored, and factor should be one. Renames are kept in
     // the same list as splits so that ordering between them is
     // respected.
 
-    // If split type is Purify, this replaces the old_var RVar to
-    // the outer Var. The inner var should be ignored, and factor
-    // should be one.
-
     // If split_type is Fuse, then this does the opposite of a
     // split, it joins the outer and inner into the old_var.
     SplitType split_type;

src/ScheduleFunctions.cpp

@@ -2248,7 +2248,6 @@ bool validate_schedule(Function f, const Stmt &s, const Target &target, bool is_
                 }
                 break;
             case Split::RenameVar:
-            case Split::PurifyRVar:
                 if (parallel_vars.count(split.outer)) {
                     parallel_vars.insert(split.old_var);
                 }

src/Serialization.cpp

@@ -338,8 +338,6 @@ Serialize::SplitType Serializer::serialize_split_type(const Split::SplitType &sp
         return Serialize::SplitType::RenameVar;
     case Split::SplitType::FuseVars:
         return Serialize::SplitType::FuseVars;
-    case Split::SplitType::PurifyRVar:
-        return Serialize::SplitType::PurifyRVar;
     default:
         user_error << "Unsupported split type\n";
         return Serialize::SplitType::SplitVar;

src/halide_ir.fbs

@@ -548,7 +548,6 @@ enum SplitType: ubyte {
     SplitVar,
     RenameVar,
     FuseVars,
-    PurifyRVar,
 }
 
 table Split {