[mlir][sparse] Introducing options for the SparseTensorConversion pass

This is work towards: https://github.com/llvm/llvm-project/issues/51652

This differential sets up the options and threads them through everywhere, but doesn't actually use them yet.  The differential that finally makes use of them is D122061, which is the final differential in the chain that fixes bug 51652.

Reviewed By: aartbik

Differential Revision: https://reviews.llvm.org/D122054

mlir/lib/Dialect/SparseTensor/Transforms/SparseTensorPasses.cpp

@@ -73,6 +73,13 @@ public:
 
 struct SparseTensorConversionPass
     : public SparseTensorConversionBase<SparseTensorConversionPass> {
+
+  SparseTensorConversionPass() = default;
+  SparseTensorConversionPass(const SparseTensorConversionPass &pass) = default;
+  SparseTensorConversionPass(const SparseTensorConversionOptions &options) {
+    sparseToSparse = static_cast<int32_t>(options.sparseToSparseStrategy);
+  }
+
   void runOnOperation() override {
     auto *ctx = &getContext();
     RewritePatternSet patterns(ctx);
@@ -106,11 +113,14 @@ struct SparseTensorConversionPass
     target
         .addLegalDialect<bufferization::BufferizationDialect, LLVM::LLVMDialect,
                          memref::MemRefDialect, scf::SCFDialect>();
+    // Translate strategy flags to strategy options.
+    SparseTensorConversionOptions options(
+        sparseToSparseConversionStrategy(sparseToSparse));
     // Populate with rules and apply rewriting rules.
     populateFunctionOpInterfaceTypeConversionPattern<FuncOp>(patterns,
                                                              converter);
     populateCallOpTypeConversionPattern(patterns, converter);
-    populateSparseTensorConversionPatterns(converter, patterns);
+    populateSparseTensorConversionPatterns(converter, patterns, options);
     if (failed(applyPartialConversion(getOperation(), target,
                                       std::move(patterns))))
       signalPassFailure();
@@ -146,6 +156,18 @@ SparseVectorizationStrategy mlir::sparseVectorizationStrategy(int32_t flag) {
   }
 }
 
+SparseToSparseConversionStrategy
+mlir::sparseToSparseConversionStrategy(int32_t flag) {
+  switch (flag) {
+  default:
+    return SparseToSparseConversionStrategy::kAuto;
+  case 1:
+    return SparseToSparseConversionStrategy::kViaCOO;
+  case 2:
+    return SparseToSparseConversionStrategy::kDirect;
+  }
+}
+
 std::unique_ptr<Pass> mlir::createSparsificationPass() {
   return std::make_unique<SparsificationPass>();
 }
@@ -158,3 +180,8 @@ mlir::createSparsificationPass(const SparsificationOptions &options) {
 std::unique_ptr<Pass> mlir::createSparseTensorConversionPass() {
   return std::make_unique<SparseTensorConversionPass>();
 }
+
+std::unique_ptr<Pass> mlir::createSparseTensorConversionPass(
+    const SparseTensorConversionOptions &options) {
+  return std::make_unique<SparseTensorConversionPass>(options);
+}