Loop Idiom Recognize Pass (LIRP) attempts to transform loops with subscripted arrays into memcpy/memset function calls. In some particular situation, this transformation introduces negative impacts.
This patch is to provide the user with options to disable part or the entire Loop Idiom Recognize Pass. The default behavior stays unchanged: no part of LIRP is disabled by default. The options will enable users to disable a particular part of the transformation, while he/she can still enjoy the benefit brought about by the rest of LIRP.