What is the difference between `-fpic` and `-fPIC` gcc parameters?

Question

I've already read the gcc manpage, but I still can't understand the difference between -fpic and -fPIC. Can someone explain it, in a very simple and clear way?

(as a bonus, you might also compare them with -fpie and -fPIE)

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Sorry if this is duplicate, but it's hard to search for a question that contains both -fpic and -fPIC.

Related questions:

• What does -fPIC mean when building a shared library?
• What, if any, are the implications of compiling objects with gcc -fPIC flag if they get used in executables?

Answer 1

http://tldp.org/HOWTO/Program-Library-HOWTO/shared-libraries.html

Use -fPIC or -fpic to generate code. Whether to use -fPIC or -fpic to generate code is target-dependent. The -fPIC choice always works, but may produce larger code than -fpic (mnenomic to remember this is that PIC is in a larger case, so it may produce larger amounts of code). Using -fpic option usually generates smaller and faster code, but will have platform-dependent limitations, such as the number of globally visible symbols or the size of the code. The linker will tell you whether it fits when you create the shared library. When in doubt, I choose -fPIC, because it always works.