I've found a compiler bug that, when commenting out a line of code, causes the kernel to run 10 times slower. Tested on an AMD 6630M 1GB (Turks) and Intel i5 2410m. The APP Kernel Analyzer shows that the kernel grows from 11714 lines of asm to 17416 lines after commenting out the single line of code. This seems a little excessive. Scratch Reg usage also goes through the roof.
Attached are NotWorking, which has the line of code commented out, and Working, which has correct output.