Revert "[flang][OpenMP] Support MLIR lowering of linear clause for om… (llvm#2288)

Author: ronlieb

flang/lib/Lower/OpenMP/ClauseProcessor.cpp

@@ -1081,40 +1081,6 @@ bool ClauseProcessor::processIsDevicePtr(
       });
 }
 
-bool ClauseProcessor::processLinear(mlir::omp::LinearClauseOps &result) const {
-  lower::StatementContext stmtCtx;
-  return findRepeatableClause<
-      omp::clause::Linear>([&](const omp::clause::Linear &clause,
-                               const parser::CharBlock &) {
-    auto &objects = std::get<omp::ObjectList>(clause.t);
-    for (const omp::Object &object : objects) {
-      semantics::Symbol *sym = object.sym();
-      const mlir::Value variable = converter.getSymbolAddress(*sym);
-      result.linearVars.push_back(variable);
-    }
-    if (objects.size()) {
-      if (auto &mod =
-              std::get<std::optional<omp::clause::Linear::StepComplexModifier>>(
-                  clause.t)) {
-        mlir::Value operand =
-            fir::getBase(converter.genExprValue(toEvExpr(*mod), stmtCtx));
-        result.linearStepVars.append(objects.size(), operand);
-      } else if (std::get<std::optional<omp::clause::Linear::LinearModifier>>(
-                     clause.t)) {
-        mlir::Location currentLocation = converter.getCurrentLocation();
-        TODO(currentLocation, "Linear modifiers not yet implemented");
-      } else {
-        // If nothing is present, add the default step of 1.
-        fir::FirOpBuilder &firOpBuilder = converter.getFirOpBuilder();
-        mlir::Location currentLocation = converter.getCurrentLocation();
-        mlir::Value operand = firOpBuilder.createIntegerConstant(
-            currentLocation, firOpBuilder.getI32Type(), 1);
-        result.linearStepVars.append(objects.size(), operand);
-      }
-    }
-  });
-}
-
 bool ClauseProcessor::processLink(
     llvm::SmallVectorImpl<DeclareTargetCapturePair> &result) const {
   return findRepeatableClause<omp::clause::Link>(

flang/lib/Lower/OpenMP/ClauseProcessor.h

@@ -128,7 +128,6 @@ class ClauseProcessor {
   bool processIsDevicePtr(
       mlir::omp::IsDevicePtrClauseOps &result,
       llvm::SmallVectorImpl<const semantics::Symbol *> &isDeviceSyms) const;
-  bool processLinear(mlir::omp::LinearClauseOps &result) const;
   bool
   processLink(llvm::SmallVectorImpl<DeclareTargetCapturePair> &result) const;
 

flang/lib/Lower/OpenMP/DataSharingProcessor.cpp

@@ -218,15 +218,14 @@ void DataSharingProcessor::collectSymbolsForPrivatization() {
   // so, we won't need to explicitely handle block objects (or forget to do
   // so).
   for (auto *sym : explicitlyPrivatizedSymbols)
-    if (!sym->test(Fortran::semantics::Symbol::Flag::OmpLinear))
-      allPrivatizedSymbols.insert(sym);
+    allPrivatizedSymbols.insert(sym);
 }
 
 bool DataSharingProcessor::needBarrier() {
   // Emit implicit barrier to synchronize threads and avoid data races on
   // initialization of firstprivate variables and post-update of lastprivate
   // variables.
-  // Emit implicit barrier for linear clause in the OpenMPIRBuilder.
+  // Emit implicit barrier for linear clause. Maybe on somewhere else.
   for (const semantics::Symbol *sym : allPrivatizedSymbols) {
     if (sym->test(semantics::Symbol::Flag::OmpLastPrivate) &&
         (sym->test(semantics::Symbol::Flag::OmpFirstPrivate) ||

flang/lib/Lower/OpenMP/OpenMP.cpp

@@ -1870,13 +1870,13 @@ static void genWsloopClauses(
     llvm::SmallVectorImpl<const semantics::Symbol *> &reductionSyms) {
   ClauseProcessor cp(converter, semaCtx, clauses);
   cp.processNowait(clauseOps);
-  cp.processLinear(clauseOps);
   cp.processOrder(clauseOps);
   cp.processOrdered(clauseOps);
   cp.processReduction(loc, clauseOps, reductionSyms);
   cp.processSchedule(stmtCtx, clauseOps);
 
-  cp.processTODO<clause::Allocate>(loc, llvm::omp::Directive::OMPD_do);
+  cp.processTODO<clause::Allocate, clause::Linear>(
+      loc, llvm::omp::Directive::OMPD_do);
 }
 
 //===----------------------------------------------------------------------===//

flang/test/Lower/OpenMP/wsloop-linear.f90

@@ -3595,9 +3595,6 @@ class CanonicalLoopInfo {
   BasicBlock *Latch = nullptr;
   BasicBlock *Exit = nullptr;
 
-  // Hold the MLIR value for the `lastiter` of the canonical loop.
-  Value *LastIter = nullptr;
-
   /// Add the control blocks of this loop to \p BBs.
   ///
   /// This does not include any block from the body, including the one returned
@@ -3630,18 +3627,6 @@ class CanonicalLoopInfo {
   void mapIndVar(llvm::function_ref<Value *(Instruction *)> Updater);
 
 public:
-  /// Sets the last iteration variable for this loop.
-  void setLastIter(Value *IterVar) { LastIter = std::move(IterVar); }
-
-  /// Returns the last iteration variable for this loop.
-  /// Certain use-cases (like translation of linear clause) may access
-  /// this variable even after a loop transformation. Hence, do not guard
-  /// this getter function by `isValid`. It is the responsibility of the
-  /// callee to ensure this functionality is not invoked by a non-outlined
-  /// CanonicalLoopInfo object (in which case, `setLastIter` will never be
-  /// invoked and `LastIter` will be by default `nullptr`).
-  Value *getLastIter() { return LastIter; }
-
   /// Returns whether this object currently represents the IR of a loop. If
   /// returning false, it may have been consumed by a loop transformation or not
   /// been intialized. Do not use in this case;

llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h

@@ -4287,7 +4287,6 @@ OpenMPIRBuilder::InsertPointOrErrorTy OpenMPIRBuilder::applyStaticWorkshareLoop(
   Value *PLowerBound = Builder.CreateAlloca(IVTy, nullptr, "p.lowerbound");
   Value *PUpperBound = Builder.CreateAlloca(IVTy, nullptr, "p.upperbound");
   Value *PStride = Builder.CreateAlloca(IVTy, nullptr, "p.stride");
-  CLI->setLastIter(PLastIter);
 
   // At the end of the preheader, prepare for calling the "init" function by
   // storing the current loop bounds into the allocated space. A canonical loop
@@ -4396,7 +4395,6 @@ OpenMPIRBuilder::applyStaticChunkedWorkshareLoop(DebugLoc DL,
   Value *PUpperBound =
       Builder.CreateAlloca(InternalIVTy, nullptr, "p.upperbound");
   Value *PStride = Builder.CreateAlloca(InternalIVTy, nullptr, "p.stride");
-  CLI->setLastIter(PLastIter);
 
   // Set up the source location value for the OpenMP runtime.
   Builder.restoreIP(CLI->getPreheaderIP());
@@ -4880,7 +4878,6 @@ OpenMPIRBuilder::applyDynamicWorkshareLoop(DebugLoc DL, CanonicalLoopInfo *CLI,
   Value *PLowerBound = Builder.CreateAlloca(IVTy, nullptr, "p.lowerbound");
   Value *PUpperBound = Builder.CreateAlloca(IVTy, nullptr, "p.upperbound");
   Value *PStride = Builder.CreateAlloca(IVTy, nullptr, "p.stride");
-  CLI->setLastIter(PLastIter);
 
   // At the end of the preheader, prepare for calling the "init" function by
   // storing the current loop bounds into the allocated space. A canonical loop