Index: mlir/include/mlir/Transforms/DialectConversion.h
===================================================================
--- mlir/include/mlir/Transforms/DialectConversion.h
+++ mlir/include/mlir/Transforms/DialectConversion.h
@@ -365,6 +365,12 @@
                                          MLIRContext *ctx,
                                          TypeConverter &converter);
 
+/// Add a pattern to the given pattern list to convert the result types of a
+/// CallOp with the given type converter.
+void populateCallOpTypeConversionPattern(OwningRewritePatternList &patterns,
+                                         MLIRContext *ctx,
+                                         TypeConverter &converter);
+
 //===----------------------------------------------------------------------===//
 // Conversion PatternRewriter
 //===----------------------------------------------------------------------===//
Index: mlir/lib/Transforms/DialectConversion.cpp
===================================================================
--- mlir/lib/Transforms/DialectConversion.cpp
+++ mlir/lib/Transforms/DialectConversion.cpp
@@ -1754,6 +1754,46 @@
   patterns.insert<FuncOpSignatureConversion>(ctx, converter);
 }
 
+/// Create a default conversion pattern that rewrites the result type of a
+/// CallOp
+namespace {
+
+struct CallOpSignatureConversion : public OpConversionPattern<CallOp> {
+  CallOpSignatureConversion(MLIRContext *ctx, TypeConverter &converter)
+      : OpConversionPattern(ctx), converter(converter) {}
+
+  /// Hook for derived classes to implement combined matching and rewriting.
+  PatternMatchResult
+  matchAndRewrite(CallOp callOp, ArrayRef<Value> operands,
+                  ConversionPatternRewriter &rewriter) const override {
+    FunctionType type = callOp.getCalleeType();
+
+    // Convert the original function results.
+    SmallVector<Type, 1> convertedResults;
+    if (failed(converter.convertTypes(type.getResults(), convertedResults)))
+      return matchFailure();
+
+    // Substitute with the new result types from the corresponding FuncType
+    // conversion.
+    auto newCallOp =
+        rewriter.create<CallOp>(callOp.getLoc(), callOp.callee(),
+                                convertedResults, callOp.getArgOperands());
+    rewriter.replaceOp(callOp, newCallOp.getResults());
+    return matchSuccess();
+  }
+
+  /// The type converter to use when rewriting the signature.
+  TypeConverter &converter;
+};
+
+} // end anonymous namespace
+
+void mlir::populateCallOpTypeConversionPattern(
+    OwningRewritePatternList &patterns, MLIRContext *ctx,
+    TypeConverter &converter) {
+  patterns.insert<CallOpSignatureConversion>(ctx, converter);
+}
+
 /// This function converts the type signature of the given block, by invoking
 /// 'convertSignatureArg' for each argument. This function should return a valid
 /// conversion for the signature on success, None otherwise.