I've done an extensive web search, but could not find an option. Conversion between model formats is available, but conversion of objective function and constraint equations into C code seems absent. This is needed to run complex models a little bit more effectively utilizing processor-specific compiler optimizations.
I have found a solution which converts NL format to C program. NL format can be obtained from AMPL input easily. https://ampl.com/netlib/ampl/solvers/nlc/index.html