If I have existing c/c++ source code, do I need to modify the code before compiling with an appropriate compiler to get the benefits of the sse4.2 instructions, or will the new compilers automagically use the sse4.2 instructions for string comparisons?
I've read all the white papers and web pages I could find that I thought would be relevant, but have yet to find a definitive answer. The best I've found is that "All existing software continues to run correctly without modification on microprocessors that incorporate SSE4, as well as in the presence of existing and new applications that incorporate SSE4." But there is no mention that the existing software will be able to take advantage of the sse4.2 instructions without modification.
Thanks in advance.