The low-level instructions substituted for an intrinsic might be more efficient than corresponding implementations in C or C++, resulting in both reduced instruction and cycle counts. To implement the intrinsic, the compiler automatically generates the best sequence of instructions for the specified target architecture. For example, the L_add intrinsic maps directly to the ARM v5TE assembly language instruction qadd:

QADD r0, r0, r1    /* Assuming r0 = a, r1 = b on entry */

More information is given to the compiler than the underlying C and C++ language is able to convey. This enables the compiler to perform optimizations and to generate instruction sequences that it could not otherwise have performed.