[FFI] Introduce small string/bytes #18185
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This PR introduces small string support to the FFI system. When the string length fit into the space in TVMFFIAny (aka len(str) <= 7). We directly store the string content into the TVMFFIAny content instead of creating a Object. This change will likely speedup small string access. Some implications: - Always check for kTVMFFISmallStr code as well as kTVMFFIStr - Always check for kTVMFFISmallBytes when checking kTVMFFIBytes - Avoid using details::StringObj, instead, always use any.as<String>() - Always set any.padding to 0 for other values (in compiler and runtime) to enable fast cmp
Hzfengsy
approved these changes
Aug 4, 2025
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This PR introduces small string support to the FFI system. When the string length fit into the space in TVMFFIAny (aka len(str) <= 7). We directly store the string content into the TVMFFIAny content instead of creating a Object. This change will likely speedup small string access.
Some implications: