diff --git a/mlir/lib/Conversion/GPUCommon/GPUOpsLowering.cpp b/mlir/lib/Conversion/GPUCommon/GPUOpsLowering.cpp
--- a/mlir/lib/Conversion/GPUCommon/GPUOpsLowering.cpp
+++ b/mlir/lib/Conversion/GPUCommon/GPUOpsLowering.cpp
@@ -46,9 +46,11 @@
   }
 
   // Rewrite the original GPU function to an LLVM function.
-  auto funcType = typeConverter->convertType(gpuFuncOp.getType())
-                      .template cast<LLVM::LLVMPointerType>()
-                      .getElementType();
+  auto convertedType = typeConverter->convertType(gpuFuncOp.getType());
+  if (!convertedType)
+    return failure();
+  auto funcType =
+      convertedType.template cast<LLVM::LLVMPointerType>().getElementType();
 
   // Remap proper input types.
   TypeConverter::SignatureConversion signatureConversion(
diff --git a/mlir/lib/Conversion/LLVMCommon/TypeConverter.cpp b/mlir/lib/Conversion/LLVMCommon/TypeConverter.cpp
--- a/mlir/lib/Conversion/LLVMCommon/TypeConverter.cpp
+++ b/mlir/lib/Conversion/LLVMCommon/TypeConverter.cpp
@@ -197,6 +197,8 @@
   SignatureConversion conversion(type.getNumInputs());
   Type converted =
       convertFunctionSignature(type, /*isVariadic=*/false, conversion);
+  if (!converted)
+    return {};
   return LLVM::LLVMPointerType::get(converted);
 }
 
@@ -300,8 +302,13 @@
 SmallVector<Type, 5>
 LLVMTypeConverter::getMemRefDescriptorFields(MemRefType type,
                                              bool unpackAggregates) {
-  assert(isStrided(type) &&
-         "Non-strided layout maps must have been normalized away");
+  if (!isStrided(type)) {
+    emitError(
+        UnknownLoc::get(type.getContext()),
+        "Conversion to strided form failed either due to non-strided layout "
+        "maps (which should have been normalized away) or other reasons");
+    return {};
+  }
 
   Type elementType = convertType(type.getElementType());
   if (!elementType)