The aliasing rules in C. Almost every single case I have found of performance-critical code being compiled suboptimally is due to redundant load/stores being e

The aliasing rules in C. Almost every single case I have found of performance-critical code being compiled suboptimally is due to redundant load/stores being emitted due to aliasing restrictions. And no, the "restrict" keyword doesn't fix much of anything. The most annoying rule is that char * pointers can alias anything... especially when one has to deal with enormous amounts of 8-bit image data.