[Mlir-commits] [mlir] [mlirbc] Serialize dense elements attr i1 using packed (PR #182233)

[Matthias Springer]

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@@ -412,6 +414,59 @@ struct TestBytecodeRoundtripPass
     doRoundtripWithConfigs(op, writeConfig, parseConfig);
   }
 
+  // Test7: When writing bytecode, we override the encoding of TestI32Type with
+  // the encoding of builtin IntegerType, but we also write an unowned blob.
+  // We can natively parse this without the use of a callback, relying on the
+  // existing builtin reader mechanism.
+  void runTest7(Operation *op) {
+    auto *builtin = op->getContext()->getLoadedDialect<mlir::BuiltinDialect>();
+    BytecodeDialectInterface *iface =
+        builtin->getRegisteredInterface<BytecodeDialectInterface>();
+    BytecodeWriterConfig writeConfig;
+    writeConfig.attachTypeCallback(
+        [&](Type entryValue, std::optional<StringRef> &dialectGroupName,
+            DialectBytecodeWriter &writer) -> LogicalResult {
+          // Emit TestIntegerType using the builtin dialect encoding.
+          if (llvm::isa<test::TestI32Type>(entryValue)) {
+            auto builtinI32Type =
+                IntegerType::get(op->getContext(), 32,
+                                 IntegerType::SignednessSemantics::Signless);
+            // Specify that this type will need to be written as part of the
+            // builtin group. This will override the default dialect group of
+            // the attribute (test).
+            dialectGroupName = StringLiteral("builtin");
+            if (succeeded(iface->writeType(builtinI32Type, writer))) {
+              char dummyBlob[] = "test_blob";
+              llvm::outs() << "Writing unowned blob...\n";
+              writer.writeUnownedBlob(ArrayRef<char>(dummyBlob, 9));
+              return success();
+            }
+          }
+          return failure();
+        });
+    ParserConfig parseConfig(op->getContext(), /*verifyAfterParse=*/true);
+    parseConfig.getBytecodeReaderConfig().attachTypeCallback(
+        [&](DialectBytecodeReader &reader, StringRef dialectName,
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matthias-springer wrote:

This lambda never returns "failure". Is that on purpose?

https://github.com/llvm/llvm-project/pull/182233