recover memory from the smaller ones. Selector lookups are not on the critical
path for message sends, so the cost of the extra memory is likely to be larger
than the cost of acquiring a lock in sel_getName().
As a side-effect of this change, method lookups for introspection are now much faster. They use the slot lookup mechanism to find which class has the method declared and then only need to do the linear search on that class, rather than doing the linear search on the entire hierarchy (slow!). If the method is not present, then they can give up after two memory accesses, rather than after searching a few hundred list entries, but that's a less important case.
I also noticed while tracking down this bug that the implementation of methodSignatureForSelector in GNUstep is very inefficient. I'll tweak that next.
The runtime was handling the message lookup correctly in this case, but only as a side-effect of the fallback code from when type-dependent dispatch is not possible. This resulted in a confusing warning message, telling you that you were calling a method with an incorrect signature, when the two signatures that it printed were the same.
This case is now handled correctly, so the warning disappears (unless you really are calling a method with the wrong signature and have TDD enabled).
Removed GNU dtable and sparse array implementations, replaced entirely now with versions based on the Étoilé runtime. Performance is roughly equivalent in microbenchmarks, memory usage is significantly lower (Gorm goes from 95MB to 50MB on my machine - this will be even more pronounced on 64-bit systems), which should improve cache usage considerably. Still room for some performance tuning, however.
Imported selector table code frm the Étoilé runtime. We can now make dispatch type dependent with a -D switch. Not enabled yet, but it will be enabled in a warning mode soon - I consider preferable to the existing GNU and Apple solution of corrupting the stack.