Delete RestrictedCanonicalizer

It doesn't work properly with the new dialect registration framework.
This was latent and only was exposed when running through npcomp-opt.
Not worth investing the brainpower to fix now.

include/npcomp/RefBackend/Passes.td

@@ -37,33 +37,4 @@ def LowerToLLVM : Pass<"refback-lower-to-llvm", "ModuleOp"> {
   let constructor = "mlir::NPCOMP::createLowerToLLVMPass();";
 }
 
-// TODO: Move this pass to upstream.
-// TODO: This pass will still do "folding" on all ops.
-// The applyPatternsAndFoldGreedily driver will need to be changed to restrict
-// folding to the specified dialects as well.
-// Perhaps a better design is having a pass that uses the conversion framework.
-// The the pass constructor would take a set of op names, and it would
-// set up a conversion target that makes all those ops illegal, and uses
-// the canonicalization patterns from those ops to legalize them.
-def RestrictedCanonicalizer : Pass<"restricted-canonicalize"> {
-  let summary = "Canonicalize operations";
-  let description = [{
-    This pass is the same as the regular `canonicalize` pass, but it only
-    applies a restricted set of patterns.
-
-    This is useful when a particular canonicalization is actually needed for
-    correctness of a lowering flow. For such cases, running a restricted set of
-    canonicalizations makes it clearer which passes are needed for correctness
-    and which passes are "just optimizations". This helps when debugging
-    miscompiles and other situations where the compiler is not behaving as
-    expected.
-  }];
-  let constructor = "mlir::NPCOMP::createRestrictedCanonicalizerPass()";
-  let options = [
-    ListOption<"includedDialects", "included-dialects", "std::string",
-               "Which dialects should be canonicalized",
-               "llvm::cl::MiscFlags::CommaSeparated">
-  ];
-}
-
 #endif // NPCOMP_REFBACKEND_PASSES

lib/RefBackend/RefBackend.cpp

@@ -116,57 +116,6 @@ mlir::NPCOMP::createLowerAllocMemRefOpsPass() {
   return std::make_unique<LowerAllocMemRefOps>();
 }
 
-//===----------------------------------------------------------------------===//
-// RestrictedCanonicalizer
-//===----------------------------------------------------------------------===//
-
-namespace {
-struct RestrictedCanonicalizer
-    : public RestrictedCanonicalizerBase<RestrictedCanonicalizer> {
-  void runOnOperation() override {
-    auto *context = &getContext();
-
-    // Find the dialects from their names.
-    DenseSet<StringRef> neededDialects;
-    for (const std::string &dialectName : includedDialects)
-      neededDialects.insert(dialectName);
-    DenseSet<Dialect *> dialectsToCanonicalize;
-    for (Dialect *dialect : context->getLoadedDialects()) {
-      if (neededDialects.count(dialect->getNamespace())) {
-        dialectsToCanonicalize.insert(dialect);
-        // Erase the dialect so that we can report an error below for any
-        // dialect names that are not loaded.
-        neededDialects.erase(dialect->getNamespace());
-      }
-    }
-
-    // Report a helpful error if a dialect is not found.
-    auto missingDialects = llvm::to_vector<6>(neededDialects);
-    if (!missingDialects.empty()) {
-      llvm::sort(missingDialects);
-      std::string buf;
-      llvm::raw_string_ostream os(buf);
-      llvm::interleaveComma(missingDialects, os);
-      llvm::report_fatal_error("restricted-canonicalize: unknown dialects: " +
-                               os.str());
-    }
-
-    // Collect all canonicalization patterns from ops in the included dialects.
-    RewritePatternSet patterns(context);
-    for (AbstractOperation *op : context->getRegisteredOperations())
-      if (dialectsToCanonicalize.count(&op->dialect))
-        op->getCanonicalizationPatterns(patterns, context);
-
-    Operation *op = getOperation();
-    (void)applyPatternsAndFoldGreedily(op->getRegions(), std::move(patterns));
-  }
-};
-} // end anonymous namespace
-
-std::unique_ptr<Pass> mlir::NPCOMP::createRestrictedCanonicalizerPass() {
-  return std::make_unique<RestrictedCanonicalizer>();
-}
-
 //===----------------------------------------------------------------------===//
 // createRefBackendLoweringPipeline
 //===----------------------------------------------------------------------===//
@@ -194,15 +143,8 @@ void mlir::NPCOMP::createRefBackendLoweringPipeline(
   pm.addNestedPass<FuncOp>(createConvertShapeConstraintsPass());
   // Run shape canonicalizations. In particular, this erases shape.assuming,
   // now that we have converted shape constraints.
-  // TODO: This is kind of ugly. Either we use pass options or a constructor
-  // that takes C++ data structures. The former makes the pass usable on the
-  // command line (including reproducers), the latter makes the pass more
-  // convenient.
-  std::unique_ptr<Pass> shapeCanonicalizer =
-      createRestrictedCanonicalizerPass();
-  if (failed(shapeCanonicalizer->initializeOptions("included-dialects=shape")))
-    llvm::report_fatal_error("couldn't initialize restricted-canonicalize");
-  pm.addPass(std::move(shapeCanonicalizer));
+  // TODO: Don't canonicalize everything.
+  pm.addNestedPass<FuncOp>(createCanonicalizerPass());
 
   // Lower shape ops to std.
   pm.addPass(createConvertShapeToStandardPass());