[Flang][OpenMP] Separate creation of work-sharing and SIMD loops, NFC (#77757)

These two constructs were both handled in `genOMP` for loop constructs.
There is some shared code between the two, but there are also enough
differences to separate these two cases into individual functions.

The shared code converting loop bounds and steps has been extracted
into a separate function.

Recursive lowering [1/5]

Author: kparzysz

flang/lib/Lower/OpenMP.cpp

@@ -2968,24 +2968,151 @@ genOMP(Fortran::lower::AbstractConverter &converter,
       standaloneConstruct.u);
 }
 
-static void genOMP(Fortran::lower::AbstractConverter &converter,
-                   Fortran::lower::pft::Evaluation &eval,
-                   Fortran::semantics::SemanticsContext &semanticsContext,
-                   const Fortran::parser::OpenMPLoopConstruct &loopConstruct) {
+static void convertLoopBounds(Fortran::lower::AbstractConverter &converter,
+                              mlir::Location loc,
+                              llvm::SmallVectorImpl<mlir::Value> &lowerBound,
+                              llvm::SmallVectorImpl<mlir::Value> &upperBound,
+                              llvm::SmallVectorImpl<mlir::Value> &step,
+                              std::size_t loopVarTypeSize) {
+  fir::FirOpBuilder &firOpBuilder = converter.getFirOpBuilder();
+  // The types of lower bound, upper bound, and step are converted into the
+  // type of the loop variable if necessary.
+  mlir::Type loopVarType = getLoopVarType(converter, loopVarTypeSize);
+  for (unsigned it = 0; it < (unsigned)lowerBound.size(); it++) {
+    lowerBound[it] =
+        firOpBuilder.createConvert(loc, loopVarType, lowerBound[it]);
+    upperBound[it] =
+        firOpBuilder.createConvert(loc, loopVarType, upperBound[it]);
+    step[it] = firOpBuilder.createConvert(loc, loopVarType, step[it]);
+  }
+}
+
+static void
+createSimdLoop(Fortran::lower::AbstractConverter &converter,
+               Fortran::lower::pft::Evaluation &eval,
+               llvm::omp::Directive ompDirective,
+               const Fortran::parser::OmpClauseList &loopOpClauseList,
+               mlir::Location loc) {
+  fir::FirOpBuilder &firOpBuilder = converter.getFirOpBuilder();
+  DataSharingProcessor dsp(converter, loopOpClauseList, eval);
+  dsp.processStep1();
+
+  Fortran::lower::StatementContext stmtCtx;
+  mlir::Value scheduleChunkClauseOperand, ifClauseOperand;
+  llvm::SmallVector<mlir::Value> lowerBound, upperBound, step, reductionVars;
+  llvm::SmallVector<mlir::Value> alignedVars, nontemporalVars;
+  llvm::SmallVector<const Fortran::semantics::Symbol *> iv;
+  llvm::SmallVector<mlir::Attribute> reductionDeclSymbols;
+  mlir::omp::ClauseOrderKindAttr orderClauseOperand;
+  mlir::IntegerAttr simdlenClauseOperand, safelenClauseOperand;
+  std::size_t loopVarTypeSize;
+
+  ClauseProcessor cp(converter, loopOpClauseList);
+  cp.processCollapse(loc, eval, lowerBound, upperBound, step, iv,
+                     loopVarTypeSize);
+  cp.processScheduleChunk(stmtCtx, scheduleChunkClauseOperand);
+  cp.processReduction(loc, reductionVars, reductionDeclSymbols);
+  cp.processTODO<Fortran::parser::OmpClause::Linear,
+                 Fortran::parser::OmpClause::Order>(loc, ompDirective);
+  cp.processIf(Fortran::parser::OmpIfClause::DirectiveNameModifier::Simd,
+               ifClauseOperand);
+  cp.processSimdlen(simdlenClauseOperand);
+  cp.processSafelen(safelenClauseOperand);
+  cp.processTODO<Fortran::parser::OmpClause::Aligned,
+                 Fortran::parser::OmpClause::Allocate,
+                 Fortran::parser::OmpClause::Nontemporal>(loc, ompDirective);
+
+  convertLoopBounds(converter, loc, lowerBound, upperBound, step,
+                    loopVarTypeSize);
+
+  mlir::TypeRange resultType;
+  auto simdLoopOp = firOpBuilder.create<mlir::omp::SimdLoopOp>(
+      loc, resultType, lowerBound, upperBound, step, alignedVars,
+      /*alignment_values=*/nullptr, ifClauseOperand, nontemporalVars,
+      orderClauseOperand, simdlenClauseOperand, safelenClauseOperand,
+      /*inclusive=*/firOpBuilder.getUnitAttr());
+  createBodyOfOp<mlir::omp::SimdLoopOp>(simdLoopOp, converter, loc, eval,
+                                        &loopOpClauseList, iv,
+                                        /*outer=*/false, &dsp);
+}
+
+static void createWsLoop(Fortran::lower::AbstractConverter &converter,
+                         Fortran::lower::pft::Evaluation &eval,
+                         llvm::omp::Directive ompDirective,
+                         const Fortran::parser::OmpClauseList &beginClauseList,
+                         const Fortran::parser::OmpClauseList *endClauseList,
+                         mlir::Location loc) {
   fir::FirOpBuilder &firOpBuilder = converter.getFirOpBuilder();
-  llvm::SmallVector<mlir::Value> lowerBound, upperBound, step, linearVars,
-      linearStepVars, reductionVars;
+  DataSharingProcessor dsp(converter, beginClauseList, eval);
+  dsp.processStep1();
+
+  Fortran::lower::StatementContext stmtCtx;
   mlir::Value scheduleChunkClauseOperand;
-  mlir::IntegerAttr orderedClauseOperand;
+  llvm::SmallVector<mlir::Value> lowerBound, upperBound, step, reductionVars;
+  llvm::SmallVector<mlir::Value> linearVars, linearStepVars;
+  llvm::SmallVector<const Fortran::semantics::Symbol *> iv;
+  llvm::SmallVector<mlir::Attribute> reductionDeclSymbols;
   mlir::omp::ClauseOrderKindAttr orderClauseOperand;
   mlir::omp::ClauseScheduleKindAttr scheduleValClauseOperand;
-  mlir::omp::ScheduleModifierAttr scheduleModClauseOperand;
   mlir::UnitAttr nowaitClauseOperand, scheduleSimdClauseOperand;
-  llvm::SmallVector<mlir::Attribute> reductionDeclSymbols;
-  Fortran::lower::StatementContext stmtCtx;
+  mlir::IntegerAttr orderedClauseOperand;
+  mlir::omp::ScheduleModifierAttr scheduleModClauseOperand;
   std::size_t loopVarTypeSize;
-  llvm::SmallVector<const Fortran::semantics::Symbol *> iv;
 
+  ClauseProcessor cp(converter, beginClauseList);
+  cp.processCollapse(loc, eval, lowerBound, upperBound, step, iv,
+                     loopVarTypeSize);
+  cp.processScheduleChunk(stmtCtx, scheduleChunkClauseOperand);
+  cp.processReduction(loc, reductionVars, reductionDeclSymbols);
+  cp.processTODO<Fortran::parser::OmpClause::Linear,
+                 Fortran::parser::OmpClause::Order>(loc, ompDirective);
+
+  convertLoopBounds(converter, loc, lowerBound, upperBound, step,
+                    loopVarTypeSize);
+
+  auto wsLoopOp = firOpBuilder.create<mlir::omp::WsLoopOp>(
+      loc, lowerBound, upperBound, step, linearVars, linearStepVars,
+      reductionVars,
+      reductionDeclSymbols.empty()
+          ? nullptr
+          : mlir::ArrayAttr::get(firOpBuilder.getContext(),
+                                 reductionDeclSymbols),
+      scheduleValClauseOperand, scheduleChunkClauseOperand,
+      /*schedule_modifiers=*/nullptr,
+      /*simd_modifier=*/nullptr, nowaitClauseOperand, orderedClauseOperand,
+      orderClauseOperand,
+      /*inclusive=*/firOpBuilder.getUnitAttr());
+
+  // Handle attribute based clauses.
+  if (cp.processOrdered(orderedClauseOperand))
+    wsLoopOp.setOrderedValAttr(orderedClauseOperand);
+
+  if (cp.processSchedule(scheduleValClauseOperand, scheduleModClauseOperand,
+                         scheduleSimdClauseOperand)) {
+    wsLoopOp.setScheduleValAttr(scheduleValClauseOperand);
+    wsLoopOp.setScheduleModifierAttr(scheduleModClauseOperand);
+    wsLoopOp.setSimdModifierAttr(scheduleSimdClauseOperand);
+  }
+  // In FORTRAN `nowait` clause occur at the end of `omp do` directive.
+  // i.e
+  // !$omp do
+  // <...>
+  // !$omp end do nowait
+  if (endClauseList) {
+    if (ClauseProcessor(converter, *endClauseList)
+            .processNowait(nowaitClauseOperand))
+      wsLoopOp.setNowaitAttr(nowaitClauseOperand);
+  }
+
+  createBodyOfOp<mlir::omp::WsLoopOp>(wsLoopOp, converter, loc, eval,
+                                      &beginClauseList, iv,
+                                      /*outer=*/false, &dsp);
+}
+
+static void genOMP(Fortran::lower::AbstractConverter &converter,
+                   Fortran::lower::pft::Evaluation &eval,
+                   Fortran::semantics::SemanticsContext &semanticsContext,
+                   const Fortran::parser::OpenMPLoopConstruct &loopConstruct) {
   const auto &beginLoopDirective =
       std::get<Fortran::parser::OmpBeginLoopDirective>(loopConstruct.t);
   const auto &loopOpClauseList =
@@ -2995,6 +3122,17 @@ static void genOMP(Fortran::lower::AbstractConverter &converter,
   const auto ompDirective =
       std::get<Fortran::parser::OmpLoopDirective>(beginLoopDirective.t).v;
 
+  const auto *endClauseList = [&]() {
+    using RetTy = const Fortran::parser::OmpClauseList *;
+    if (auto &endLoopDirective =
+            std::get<std::optional<Fortran::parser::OmpEndLoopDirective>>(
+                loopConstruct.t)) {
+      return RetTy(
+          &std::get<Fortran::parser::OmpClauseList>((*endLoopDirective).t));
+    }
+    return RetTy();
+  }();
+
   bool validDirective = false;
   if (llvm::omp::topTaskloopSet.test(ompDirective)) {
     validDirective = true;
@@ -3033,97 +3171,14 @@ static void genOMP(Fortran::lower::AbstractConverter &converter,
                               ")");
   }
 
-  DataSharingProcessor dsp(converter, loopOpClauseList, eval);
-  dsp.processStep1();
-
-  ClauseProcessor cp(converter, loopOpClauseList);
-  cp.processCollapse(currentLocation, eval, lowerBound, upperBound, step, iv,
-                     loopVarTypeSize);
-  cp.processScheduleChunk(stmtCtx, scheduleChunkClauseOperand);
-  cp.processReduction(currentLocation, reductionVars, reductionDeclSymbols);
-  cp.processTODO<Fortran::parser::OmpClause::Linear,
-                 Fortran::parser::OmpClause::Order>(currentLocation,
-                                                    ompDirective);
-
-  // The types of lower bound, upper bound, and step are converted into the
-  // type of the loop variable if necessary.
-  mlir::Type loopVarType = getLoopVarType(converter, loopVarTypeSize);
-  for (unsigned it = 0; it < (unsigned)lowerBound.size(); it++) {
-    lowerBound[it] = firOpBuilder.createConvert(currentLocation, loopVarType,
-                                                lowerBound[it]);
-    upperBound[it] = firOpBuilder.createConvert(currentLocation, loopVarType,
-                                                upperBound[it]);
-    step[it] =
-        firOpBuilder.createConvert(currentLocation, loopVarType, step[it]);
-  }
-
   // 2.9.3.1 SIMD construct
   if (llvm::omp::allSimdSet.test(ompDirective)) {
-    llvm::SmallVector<mlir::Value> alignedVars, nontemporalVars;
-    mlir::Value ifClauseOperand;
-    mlir::IntegerAttr simdlenClauseOperand, safelenClauseOperand;
-    cp.processIf(Fortran::parser::OmpIfClause::DirectiveNameModifier::Simd,
-                 ifClauseOperand);
-    cp.processSimdlen(simdlenClauseOperand);
-    cp.processSafelen(safelenClauseOperand);
-    cp.processTODO<Fortran::parser::OmpClause::Aligned,
-                   Fortran::parser::OmpClause::Allocate,
-                   Fortran::parser::OmpClause::Nontemporal>(currentLocation,
-                                                            ompDirective);
-
-    mlir::TypeRange resultType;
-    auto simdLoopOp = firOpBuilder.create<mlir::omp::SimdLoopOp>(
-        currentLocation, resultType, lowerBound, upperBound, step, alignedVars,
-        /*alignment_values=*/nullptr, ifClauseOperand, nontemporalVars,
-        orderClauseOperand, simdlenClauseOperand, safelenClauseOperand,
-        /*inclusive=*/firOpBuilder.getUnitAttr());
-    createBodyOfOp<mlir::omp::SimdLoopOp>(
-        simdLoopOp, converter, currentLocation, eval, &loopOpClauseList, iv,
-        /*outer=*/false, &dsp);
-    return;
-  }
-
-  auto wsLoopOp = firOpBuilder.create<mlir::omp::WsLoopOp>(
-      currentLocation, lowerBound, upperBound, step, linearVars, linearStepVars,
-      reductionVars,
-      reductionDeclSymbols.empty()
-          ? nullptr
-          : mlir::ArrayAttr::get(firOpBuilder.getContext(),
-                                 reductionDeclSymbols),
-      scheduleValClauseOperand, scheduleChunkClauseOperand,
-      /*schedule_modifiers=*/nullptr,
-      /*simd_modifier=*/nullptr, nowaitClauseOperand, orderedClauseOperand,
-      orderClauseOperand,
-      /*inclusive=*/firOpBuilder.getUnitAttr());
-
-  // Handle attribute based clauses.
-  if (cp.processOrdered(orderedClauseOperand))
-    wsLoopOp.setOrderedValAttr(orderedClauseOperand);
-
-  if (cp.processSchedule(scheduleValClauseOperand, scheduleModClauseOperand,
-                         scheduleSimdClauseOperand)) {
-    wsLoopOp.setScheduleValAttr(scheduleValClauseOperand);
-    wsLoopOp.setScheduleModifierAttr(scheduleModClauseOperand);
-    wsLoopOp.setSimdModifierAttr(scheduleSimdClauseOperand);
-  }
-  // In FORTRAN `nowait` clause occur at the end of `omp do` directive.
-  // i.e
-  // !$omp do
-  // <...>
-  // !$omp end do nowait
-  if (const auto &endClauseList =
-          std::get<std::optional<Fortran::parser::OmpEndLoopDirective>>(
-              loopConstruct.t)) {
-    const auto &clauseList =
-        std::get<Fortran::parser::OmpClauseList>((*endClauseList).t);
-    if (ClauseProcessor(converter, clauseList)
-            .processNowait(nowaitClauseOperand))
-      wsLoopOp.setNowaitAttr(nowaitClauseOperand);
+    createSimdLoop(converter, eval, ompDirective, loopOpClauseList,
+                   currentLocation);
+  } else {
+    createWsLoop(converter, eval, ompDirective, loopOpClauseList, endClauseList,
+                 currentLocation);
   }
-
-  createBodyOfOp<mlir::omp::WsLoopOp>(wsLoopOp, converter, currentLocation,
-                                      eval, &loopOpClauseList, iv,
-                                      /*outer=*/false, &dsp);
 }
 
 static void