[flang] de-duplicate CFGConversion pass (#89783)

See RFC at
https://discourse.llvm.org/t/rfc-add-an-interface-for-top-level-container-operations

I previously did the same for the AbstractResult pass
#88867

flang/include/flang/Optimizer/Transforms/Passes.h

@@ -37,8 +37,7 @@ namespace fir {
 #define GEN_PASS_DECL_ANNOTATECONSTANTOPERANDS
 #define GEN_PASS_DECL_ARRAYVALUECOPY
 #define GEN_PASS_DECL_CHARACTERCONVERSION
-#define GEN_PASS_DECL_CFGCONVERSIONONFUNC
-#define GEN_PASS_DECL_CFGCONVERSIONONREDUCTION
+#define GEN_PASS_DECL_CFGCONVERSION
 #define GEN_PASS_DECL_EXTERNALNAMECONVERSION
 #define GEN_PASS_DECL_MEMREFDATAFLOWOPT
 #define GEN_PASS_DECL_SIMPLIFYINTRINSICS
@@ -53,8 +52,6 @@ namespace fir {
 std::unique_ptr<mlir::Pass> createAffineDemotionPass();
 std::unique_ptr<mlir::Pass>
 createArrayValueCopyPass(fir::ArrayValueCopyOptions options = {});
-std::unique_ptr<mlir::Pass> createFirToCfgOnFuncPass();
-std::unique_ptr<mlir::Pass> createFirToCfgOnReductionPass();
 std::unique_ptr<mlir::Pass> createCharacterConversionPass();
 std::unique_ptr<mlir::Pass> createExternalNameConversionPass();
 std::unique_ptr<mlir::Pass>

flang/include/flang/Optimizer/Transforms/Passes.td

@@ -137,8 +137,7 @@ def CharacterConversion : Pass<"character-conversion"> {
   ];
 }
 
-class CFGConversionBase<string optExt, string operation>
-  : Pass<"cfg-conversion-on-" # optExt # "-opt", operation> {
+def CFGConversion : Pass<"cfg-conversion"> {
   let summary = "Convert FIR structured control flow ops to CFG ops.";
   let description = [{
     Transform the `fir.do_loop`, `fir.if`, `fir.iterate_while` and
@@ -157,14 +156,6 @@ class CFGConversionBase<string optExt, string operation>
   ];
 }
 
-def CFGConversionOnFunc : CFGConversionBase<"func", "mlir::func::FuncOp"> {
-  let constructor = "::fir::createFirToCfgOnFuncPass()";
-}
-
-def CFGConversionOnReduction : CFGConversionBase<"reduce", "mlir::omp::DeclareReductionOp"> {
-  let constructor = "::fir::createFirToCfgOnReductionPass()";
-}
-
 def ExternalNameConversion : Pass<"external-name-interop", "mlir::ModuleOp"> {
   let summary = "Convert name for external interoperability";
   let description = [{

flang/include/flang/Tools/CLOptions.inc

@@ -87,8 +87,6 @@ DisableOption(BoxedProcedureRewrite, "boxed-procedure-rewrite",
 DisableOption(ExternalNameConversion, "external-name-interop",
     "convert names with external convention");
 
-// TODO: remove once these are used for non-codegen passes
-#if !defined(FLANG_EXCLUDE_CODEGEN)
 using PassConstructor = std::unique_ptr<mlir::Pass>();
 
 template <typename OP>
@@ -108,7 +106,12 @@ void addNestedPassToAllTopLevelOperations(
   addNestedPassToOps<mlir::func::FuncOp, mlir::omp::DeclareReductionOp,
       fir::GlobalOp>(pm, ctor);
 }
-#endif
+
+void addNestedPassToAllTopLevelOperationsConditionally(mlir::PassManager &pm,
+    llvm::cl::opt<bool> &disabled, PassConstructor ctor) {
+  if (!disabled)
+    addNestedPassToAllTopLevelOperations(pm, ctor);
+}
 
 /// Generic for adding a pass to the pass manager if it is not disabled.
 template <typename F>
@@ -146,10 +149,8 @@ static void addCanonicalizerPassWithoutRegionSimplification(
 }
 
 inline void addCfgConversionPass(mlir::PassManager &pm) {
-  addNestedPassConditionally<mlir::func::FuncOp>(
-      pm, disableCfgConversion, fir::createFirToCfgOnFuncPass);
-  addNestedPassConditionally<mlir::omp::DeclareReductionOp>(
-      pm, disableCfgConversion, fir::createFirToCfgOnReductionPass);
+  addNestedPassToAllTopLevelOperationsConditionally(
+      pm, disableCfgConversion, fir::createCFGConversion);
 }
 
 inline void addAVC(

flang/lib/Optimizer/Transforms/ControlFlowConverter.cpp

@@ -24,8 +24,7 @@
 #include "llvm/Support/CommandLine.h"
 
 namespace fir {
-#define GEN_PASS_DEF_CFGCONVERSIONONFUNC
-#define GEN_PASS_DEF_CFGCONVERSIONONREDUCTION
+#define GEN_PASS_DEF_CFGCONVERSION
 #include "flang/Optimizer/Transforms/Passes.h.inc"
 } // namespace fir
 
@@ -309,9 +308,10 @@ class CfgIterWhileConv : public mlir::OpRewritePattern<fir::IterWhileOp> {
 };
 
 /// Convert FIR structured control flow ops to CFG ops.
-template <typename Pass, template <typename> class PassBase>
-class CfgConversionTemplate : public PassBase<Pass> {
+class CfgConversion : public fir::impl::CFGConversionBase<CfgConversion> {
 public:
+  using CFGConversionBase<CfgConversion>::CFGConversionBase;
+
   void runOnOperation() override {
     auto *context = &this->getContext();
     mlir::RewritePatternSet patterns(context);
@@ -333,14 +333,6 @@ class CfgConversionTemplate : public PassBase<Pass> {
   }
 };
 
-class CfgConversionOnFunc
-    : public CfgConversionTemplate<CfgConversionOnFunc,
-                                   ::fir::impl::CFGConversionOnFuncBase> {};
-
-class CfgConversionOnReduction
-    : public CfgConversionTemplate<CfgConversionOnReduction,
-                                   ::fir::impl::CFGConversionOnReductionBase> {
-};
 } // namespace
 
 /// Expose conversion rewriters to other passes
@@ -349,13 +341,3 @@ void fir::populateCfgConversionRewrites(mlir::RewritePatternSet &patterns,
   patterns.insert<CfgLoopConv, CfgIfConv, CfgIterWhileConv>(
       patterns.getContext(), forceLoopToExecuteOnce);
 }
-
-/// Convert FIR's structured control flow ops to CFG ops.  This
-/// conversion enables the `createLowerToCFGPass` to transform these to CFG
-/// form.
-std::unique_ptr<mlir::Pass> fir::createFirToCfgOnFuncPass() {
-  return std::make_unique<CfgConversionOnFunc>();
-}
-std::unique_ptr<mlir::Pass> fir::createFirToCfgOnReductionPass() {
-  return std::make_unique<CfgConversionOnReduction>();
-}

flang/test/Driver/bbc-mlir-pass-pipeline.f90

@@ -38,12 +38,14 @@
 ! CHECK-NEXT:   (S) 0 num-cse'd - Number of operations CSE'd
 ! CHECK-NEXT:   (S) 0 num-dce'd - Number of operations DCE'd
 
-! CHECK-NEXT: Pipeline Collection : ['func.func', 'omp.declare_reduction']
+! CHECK-NEXT: Pipeline Collection : ['fir.global', 'func.func', 'omp.declare_reduction']
+! CHECK-NEXT: 'fir.global' Pipeline
+! CHECK-NEXT:   CFGConversion
 ! CHECK-NEXT: 'func.func' Pipeline
 ! CHECK-NEXT:   PolymorphicOpConversion
-! CHECK-NEXT:   CFGConversionOnFunc
+! CHECK-NEXT:   CFGConversion
 ! CHECK-NEXT: 'omp.declare_reduction' Pipeline
-! CHECK-NEXT:   CFGConversionOnReduction
+! CHECK-NEXT:   CFGConversion
 
 ! CHECK-NEXT: SCFToControlFlow
 ! CHECK-NEXT: Canonicalizer

flang/test/Driver/mlir-debug-pass-pipeline.f90

@@ -58,12 +58,14 @@
 ! ALL-NEXT:   (S) 0 num-cse'd - Number of operations CSE'd
 ! ALL-NEXT:   (S) 0 num-dce'd - Number of operations DCE'd
 
-! ALL-NEXT: Pipeline Collection : ['func.func', 'omp.declare_reduction']
+! ALL-NEXT: Pipeline Collection : ['fir.global', 'func.func', 'omp.declare_reduction']
+! ALL-NEXT:   'fir.global' Pipeline
+! ALL-NEXT:     CFGConversion
 ! ALL-NEXT:   'func.func' Pipeline
 ! ALL-NEXT:     PolymorphicOpConversion
-! ALL-NEXT:     CFGConversionOnFunc
+! ALL-NEXT:     CFGConversion
 ! ALL-NEXT:   'omp.declare_reduction' Pipeline
-! ALL-NEXT:     CFGConversionOnReduction
+! ALL-NEXT:     CFGConversion
 ! ALL-NEXT: SCFToControlFlow
 ! ALL-NEXT: Canonicalizer
 ! ALL-NEXT: SimplifyRegionLite

flang/test/Driver/mlir-pass-pipeline.f90

@@ -52,12 +52,14 @@
 ! O2-NEXT:    'func.func' Pipeline
 ! O2-NEXT:      PolymorphicOpConversion
 ! O2-NEXT:  AddAliasTags
-! ALL-NEXT: Pipeline Collection : ['func.func', 'omp.declare_reduction']
+! ALL-NEXT: Pipeline Collection : ['fir.global', 'func.func', 'omp.declare_reduction']
+! ALL-NEXT:    'fir.global' Pipeline
+! ALL-NEXT:      CFGConversion
 ! ALL-NEXT:    'func.func' Pipeline
 ! NOTO2-NEXT:      PolymorphicOpConversion
-! ALL-NEXT:      CFGConversionOnFunc
+! ALL-NEXT:      CFGConversion
 ! ALL-NEXT:   'omp.declare_reduction' Pipeline
-! ALL-NEXT:      CFGConversionOnReduction
+! ALL-NEXT:      CFGConversion
 
 ! ALL-NEXT: SCFToControlFlow
 ! ALL-NEXT: Canonicalizer

flang/test/Fir/array-value-copy-2.fir

@@ -1,5 +1,5 @@
-// RUN: fir-opt --array-value-copy --cfg-conversion-on-func-opt %s | FileCheck %s
-// RUN: fir-opt --array-value-copy="optimize-conflicts=true" --cfg-conversion-on-func-opt %s | FileCheck %s
+// RUN: fir-opt --array-value-copy --cfg-conversion %s | FileCheck %s
+// RUN: fir-opt --array-value-copy="optimize-conflicts=true" --cfg-conversion %s | FileCheck %s
 
 // CHECK-LABEL: func @_QPslice1(
 // CHECK-NOT: fir.allocmem

flang/test/Fir/basic-program.fir

@@ -60,11 +60,13 @@ func.func @_QQmain() {
 
 // PASSES-NEXT: AddAliasTags
 
-// PASSES-NEXT: Pipeline Collection : ['func.func', 'omp.declare_reduction']
+// PASSES-NEXT: Pipeline Collection : ['fir.global', 'func.func', 'omp.declare_reduction']
+// PASSES-NEXT: 'fir.global' Pipeline
+// PASSES-NEXT:   CFGConversion
 // PASSES-NEXT: 'func.func' Pipeline
-// PASSES-NEXT:   CFGConversionOnFunc
+// PASSES-NEXT:   CFGConversion
 // PASSES-NEXT: 'omp.declare_reduction' Pipeline
-// PASSES-NEXT:   CFGConversionOnReduction
+// PASSES-NEXT:   CFGConversion
 
 // PASSES-NEXT: SCFToControlFlow
 // PASSES-NEXT: Canonicalizer

flang/test/Fir/convert-to-llvm-openmp-and-fir.fir

@@ -1,4 +1,4 @@
-// RUN: fir-opt --split-input-file --cfg-conversion-on-func-opt --fir-to-llvm-ir="target=aarch64-unknown-linux-gnu" %s | FileCheck %s
+// RUN: fir-opt --split-input-file --cfg-conversion --fir-to-llvm-ir="target=aarch64-unknown-linux-gnu" %s | FileCheck %s
 
 func.func @_QPsb1(%arg0: !fir.ref<i32> {fir.bindc_name = "n"}, %arg1: !fir.ref<!fir.array<?xi32>> {fir.bindc_name = "arr"}) {
   %c1_i64 = arith.constant 1 : i64

flang/test/Fir/loop01.fir

@@ -1,4 +1,4 @@
-// RUN: fir-opt --split-input-file --cfg-conversion-on-func-opt %s | FileCheck %s
+// RUN: fir-opt --split-input-file --cfg-conversion %s | FileCheck %s
 
 func.func @x(%lb : index, %ub : index, %step : index, %b : i1, %addr : !fir.ref<index>) {
   fir.do_loop %iv = %lb to %ub step %step unordered {

flang/test/Fir/loop02.fir

@@ -1,5 +1,5 @@
-// RUN: fir-opt --cfg-conversion-on-func-opt="always-execute-loop-body=true" %s | FileCheck %s
-// RUN: fir-opt --cfg-conversion-on-func-opt %s | FileCheck %s --check-prefix=NOOPT
+// RUN: fir-opt --cfg-conversion="always-execute-loop-body=true" %s | FileCheck %s
+// RUN: fir-opt --cfg-conversion %s | FileCheck %s --check-prefix=NOOPT
 
 func.func @x(%addr : !fir.ref<index>) {
   %bound = arith.constant 452 : index

flang/test/Lower/OpenMP/FIR/flush.f90

@@ -1,7 +1,7 @@
 ! This test checks lowering of OpenMP Flush Directive.
 
 !RUN: %flang_fc1 -emit-fir -flang-deprecated-no-hlfir -fopenmp %s -o - | FileCheck %s --check-prefixes="FIRDialect,OMPDialect"
-!RUN: %flang_fc1 -emit-fir -flang-deprecated-no-hlfir -fopenmp %s -o - | fir-opt --cfg-conversion-on-func-opt | fir-opt --fir-to-llvm-ir | FileCheck %s --check-prefixes="LLVMIRDialect,OMPDialect"
+!RUN: %flang_fc1 -emit-fir -flang-deprecated-no-hlfir -fopenmp %s -o - | fir-opt --cfg-conversion | fir-opt --fir-to-llvm-ir | FileCheck %s --check-prefixes="LLVMIRDialect,OMPDialect"
 
 subroutine flush_standalone(a, b, c)
     integer, intent(inout) :: a, b, c

flang/test/Lower/OpenMP/FIR/master.f90

@@ -1,5 +1,5 @@
 !RUN: %flang_fc1 -emit-fir -flang-deprecated-no-hlfir -fopenmp %s -o - | FileCheck %s --check-prefixes="FIRDialect,OMPDialect"
-!RUN: %flang_fc1 -emit-fir -flang-deprecated-no-hlfir -fopenmp %s -o - | fir-opt --cfg-conversion-on-func-opt | fir-opt --fir-to-llvm-ir | FileCheck %s --check-prefixes="OMPDialect"
+!RUN: %flang_fc1 -emit-fir -flang-deprecated-no-hlfir -fopenmp %s -o - | fir-opt --cfg-conversion | fir-opt --fir-to-llvm-ir | FileCheck %s --check-prefixes="OMPDialect"
 
 !===============================================================================
 ! parallel construct with function call which has master construct internally

flang/test/Lower/OpenMP/FIR/parallel-sections.f90

@@ -1,7 +1,7 @@
 ! REQUIRES: openmp_runtime
 
 !RUN: %flang_fc1 -emit-fir -flang-deprecated-no-hlfir -fopenmp %s -o - | FileCheck %s --check-prefixes="FIRDialect,OMPDialect"
-!RUN: %flang_fc1 -emit-fir -flang-deprecated-no-hlfir -fopenmp %s -o - | fir-opt --cfg-conversion-on-func-opt | fir-opt --fir-to-llvm-ir | FileCheck %s --check-prefixes="OMPDialect,LLVMDialect"
+!RUN: %flang_fc1 -emit-fir -flang-deprecated-no-hlfir -fopenmp %s -o - | fir-opt --cfg-conversion | fir-opt --fir-to-llvm-ir | FileCheck %s --check-prefixes="OMPDialect,LLVMDialect"
 
 !===============================================================================
 ! Parallel sections construct

flang/test/Transforms/omp-reduction-cfg-conversion.fir

@@ -1,4 +1,4 @@
-// RUN: fir-opt --cfg-conversion-on-reduce-opt %s | FileCheck %s
+// RUN: fir-opt --cfg-conversion %s | FileCheck %s
 
 omp.declare_reduction @add_reduction_i_32_box_3_byref : !fir.ref<!fir.box<!fir.array<3xi32>>> init {
 ^bb0(%arg0: !fir.ref<!fir.box<!fir.array<3xi32>>>):