openfheorg / openfhe-wasm Goto Github PK

1. After compiling wasm, the UT for ckks or bgv cannot pass. The program will throw an exception here, causing UT failure. After analysis, it is this code snippet that throws the exception:
   IntType FirstPrime(uint32_t nBits, uint32_t m) {
   std::cout << "FirstPrime() enter" << std::endl;
   if constexpr (std::is_same_v<IntType, NativeInteger>) {
   if (nBits > MAX_MODULUS_SIZE)
   OPENFHE_THROW(config_error, std::string(func) + ": Requested bit length " + std::to_string(nBits) +
   " exceeds maximum allowed length " + std::to_string(MAX_MODULUS_SIZE));
   }
   The reason is that HAVE_INT128 is not defined in emmake, so the value of MAX_MODULUS_SIZE is 57. Therefore, the condition nBits (59) > MAX_MODULUS_SIZE holds true, leading to an exception being thrown.
   2.Modifying the original code:
   #if defined(HAVE_INT128)
   #define MAX_MODULUS_SIZE 60
   using BasicInteger = uint64_t;
   using DoubleNativeInt = unsigned __int128;
   using uint128_t = unsigned __int128;
   using int128_t = __int128;
   #else
   #define MAX_MODULUS_SIZE 57 ---- modify to 60
   using BasicInteger = uint64_t;
   using DoubleNativeInt = uint64_t;
   using uint128_t = uint64_t;
   using int128_t = int64_t;
   #endif
   Although no longer throwing an exception, will cause the function WitnessFunction(RNG(p - THREE).ModAdd(TWO, p), d, s, p) to always return True, preventing the exit from the FirstPrime function.
   3.Restore #define MAX_MODULUS_SIZE 57, then add a line of code to /openfhe-development/embuild/src/core/config_core.h, recompile wasm, and the UT can pass. However, there may be risks, as follows: wasm does not support 128 bits, // Note that FLEXIBLEAUTO is not supported for 128-bit CKKS In the CMakeLists.txt file at line 278 in the openfhe-development directory, it clearly states: NATIVE_SIZE == 128 is not supported for EMSCRIPTEN.
   if( "${NATIVE_SIZE}" EQUAL 128 )
   if ( EMSCRIPTEN )
   message(SEND_ERROR "NATIVE_SIZE == 128 is not supported for EMSCRIPTEN")
   endif()
   if( ${HAVE_INT128} )
   set( NATIVEINT 128 )
   message (STATUS "NATIVEINT is set to " ${NATIVEINT})
   else()
   message(SEND_ERROR "Cannot support NATIVE_SIZE == 128")

In conclusion, my question is, is it feasible to compile wasm by defining HAVE_INT128 as TRUE? If not, what risks might be involved?