Recent research on high-speed cryptography has been striving for performance by twiddling with instructions, but without an automated tool, writing fast software takes much precious labor effort. We present a tool with a simple interface for crypto developers to generate fast modular multiplication routines in a few keystrokes: you provide the prime as the modulus and it produces several candidate results or enumerates them all for benchmark. Specifically, we automatized the choice of number representation and the code generation for multiplication modulo a pseudo-Mesenne prime on ARM11, using the proposed convolved multiplication method, which interleaves multiplication and modular reduction. The high-quality code generated runs up to 16.4% faster than the convolved multiplication compiled by defacto-standard compilers such as gcc, and is 4 to 8 times faster than the GMP modular multiplication.