How to exactly know if an exe or dll file is 64bit or 32bit?

I know {desc} includes the information I need.
image
but that is not precise enough.
if adding some comment, like this:
image
the comment will be included in {desc}.
image

As the object item.metadata.other.autodesc contains too much information rather than just "AMD64 or I386 or ARM64",
So, how to exactly get "AMD64 or I386 or ARM64" infomation from exe/dll file?

	var desc =data.item.metadata.other.autodesc;
	if (desc.indexOf("AMD64,") !=-1) data.value = "x64 / 64bit";
	else if (desc.indexOf("I386,") !=-1) data.value = "x86 / 32bit";
	else if (desc.indexOf("ARM64,") !=-1) data.value = "ARM64";
	else data.value = "";