Expose cfg conversions to other passes

Author: tblah

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

@@ -99,6 +99,9 @@ createFunctionAttrPass(FunctionAttrTypes &functionAttr, bool noInfsFPMath,
                        bool noNaNsFPMath, bool approxFuncFPMath,
                        bool noSignedZerosFPMath, bool unsafeFPMath);
 
+void populateCfgConversionRewrites(mlir::RewritePatternSet &patterns,
+                                   bool forceLoopToExecuteOnce = false);
+
 // declarative passes
 #define GEN_PASS_REGISTRATION
 #include "flang/Optimizer/Transforms/Passes.h.inc"

flang/lib/Optimizer/Transforms/ControlFlowConverter.cpp

@@ -315,8 +315,7 @@ class CfgConversionTemplate : public PassBase<Pass> {
   void runOnOperation() override {
     auto *context = &this->getContext();
     mlir::RewritePatternSet patterns(context);
-    patterns.insert<CfgLoopConv, CfgIfConv, CfgIterWhileConv>(
-        context, this->forceLoopToExecuteOnce);
+    fir::populateCfgConversionRewrites(patterns, this->forceLoopToExecuteOnce);
     mlir::ConversionTarget target(*context);
     target.addLegalDialect<mlir::affine::AffineDialect,
                            mlir::cf::ControlFlowDialect, FIROpsDialect,
@@ -344,6 +343,13 @@ class CfgConversionOnReduction
 };
 } // namespace
 
+/// Expose conversion rewriters to other passes
+void fir::populateCfgConversionRewrites(mlir::RewritePatternSet &patterns,
+                                        bool forceLoopToExecuteOnce) {
+  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.