Merge pull request #507 from schweitzpgi/ch-work2

Split out the target rewrite pass into its own source file.

Author: schweitzpgi

flang/include/flang/Lower/PFTBuilder.h

@@ -21,6 +21,8 @@
 #include "flang/Common/template.h"
 #include "flang/Lower/Utils.h"
 #include "flang/Parser/parse-tree.h"
+#include "flang/Semantics/attr.h"
+#include "flang/Semantics/symbol.h"
 #include "llvm/Support/raw_ostream.h"
 
 namespace mlir {
@@ -32,9 +34,11 @@ namespace semantics {
 class SemanticsContext;
 class Scope;
 } // namespace semantics
+
 namespace lower {
 
 bool definedInCommonBlock(const semantics::Symbol &sym);
+bool defaultRecursiveFunctionSetting();
 
 namespace pft {
 
@@ -70,6 +74,10 @@ class ReferenceVariantBase {
     return std::get<Ref<B>>(u).get();
   }
   template <typename B>
+  constexpr BaseType<B> &getStatement() const {
+    return std::get<Ref<parser::Statement<B>>>(u).get().statement;
+  }
+  template <typename B>
   constexpr BaseType<B> *getIf() const {
     auto *ptr = std::get_if<Ref<B>>(&u);
     return ptr ? &ptr->get() : nullptr;
@@ -547,6 +555,14 @@ struct FunctionLikeUnit : public ProgramUnit {
   FunctionLikeUnit(FunctionLikeUnit &&) = default;
   FunctionLikeUnit(const FunctionLikeUnit &) = delete;
 
+  bool isRecursive() const {
+    auto sym = getSubprogramSymbol();
+    return !isMainProgram() &&
+           (sym.attrs().test(semantics::Attr::RECURSIVE) ||
+            (!sym.attrs().test(semantics::Attr::NON_RECURSIVE) &&
+             defaultRecursiveFunctionSetting()));
+  }
+
   std::vector<Variable> getOrderedSymbolTable() { return varList[0]; }
 
   bool isMainProgram() const {
@@ -574,6 +590,7 @@ struct FunctionLikeUnit : public ProgramUnit {
     assert(symbol && "not inside a procedure");
     return *symbol;
   }
+
   /// Return a pointer to the current entry point Evaluation.
   /// This is null for a primary entry point.
   Evaluation *getEntryEval() const {

flang/lib/Lower/Bridge.cpp

@@ -1732,7 +1732,6 @@ class FirConverter : public Fortran::lower::AbstractConverter {
     auto globalName = mangleName(sym);
     bool isConst = sym.attrs().test(Fortran::semantics::Attr::PARAMETER);
     auto loc = genLocation(sym.name());
-    auto idxTy = builder->getIndexType();
     // FIXME: name returned does not consider subprogram's scope, is not unique
     fir::GlobalOp global = builder->getNamedGlobal(globalName);
     if (global) {

flang/lib/Lower/PFTBuilder.cpp

@@ -23,6 +23,12 @@ static llvm::cl::opt<bool> clDisableStructuredFir(
     "no-structured-fir", llvm::cl::desc("disable generation of structured FIR"),
     llvm::cl::init(false), llvm::cl::Hidden);
 
+static llvm::cl::opt<bool> nonRecursiveProcedures(
+    "non-recursive-procedures",
+    llvm::cl::desc("Make procedures non-recursive by default. This was the "
+                   "default for all Fortran standards prior to 2018."),
+    llvm::cl::init(/*2018 standard=*/false));
+
 using namespace Fortran;
 
 namespace {
@@ -1344,6 +1350,14 @@ Fortran::lower::createPFT(const parser::Program &root,
   return walker.result();
 }
 
+// FIXME: FlangDriver
+// This option should be integrated with the real driver as the default of
+// RECURSIVE vs. NON_RECURSIVE may be changed by other command line options,
+// etc., etc.
+bool Fortran::lower::defaultRecursiveFunctionSetting() {
+  return !nonRecursiveProcedures;
+}
+
 void Fortran::lower::dumpPFT(llvm::raw_ostream &outputStream,
                              const lower::pft::Program &pft) {
   PFTDumper{}.dumpPFT(outputStream, pft);

flang/lib/Optimizer/CMakeLists.txt

@@ -16,6 +16,7 @@ add_flang_library(FIROptimizer
   CodeGen/CodeGen.cpp
   CodeGen/PreCGRewrite.cpp
   CodeGen/Target.cpp
+  CodeGen/TargetRewrite.cpp
 
   Transforms/ControlFlowConverter.cpp
   Transforms/CSE.cpp