David Brown <david.br...@hesbynett.no> wrote: > However, the compiler has a much > better chance of doing bounds checking, alias checking, and other > optimisations on the array expression.
Why? Either the compiler knows at compile-time that "foo" is actually an array it has detailed information about, then it can perform bounds-checking etc. on it, regardless which of both expressions you're writing (assuming it performs any kind of bounds checking at all -- I'm not sure GCC does). However, if "foo" is a pointer of unknown source, no checks can be applied regardless of whether you're writing &foo[i] or foo + i. (Some optimizations can be applied if foo is a pointer passed as a function argument, and qualified "restrict".) > Additionally, &foo[i] and (foo + i) read as different things (one is > the address of an element, the other is the address of an array plus > an offset). However, given the way an offset is computed in C, the result is again: the address of an element (possibly an element of a dynamic array). -- cheers, J"org .-.-. --... ...-- -.. . DL8DTL http://www.sax.de/~joerg/ NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-) _______________________________________________ AVR-GCC-list mailing list AVR-GCC-list@nongnu.org http://lists.nongnu.org/mailman/listinfo/avr-gcc-list
