Paul Schlie <[EMAIL PROTECTED]> writes: > I presume that "code" can/should be optimally generated once by initially > optimally covering the rtl representing a basic block (with minimal cost > in either storage, cycles or some hybrid of both); where there's then no > need to ever subsequently screw with it again (although various basic > block partitioning resulting from various loop transformations strategies, > etc. may require multiple mappings to determine their relative costs). > > Where this presumption basically ideally requires that the target be > described as accurately as possible entirely in rtl, with no reliance > on procedural or peephole optimization, relying entirely on GCC to > optimally cover the program's basic-block rtl optimally with rtl > instruction description equivalents; thereby by fully exposing all > dependencies, an optimal instruction schedule will naturally result > from an optimal rtl graph covering without needing to perform an > explicit further optimization for example. > > (is this not feasible if the target is accurately described in rtl?)
I don't know how to respond to this. I'm discussing a way to achieve an incremental improvement in gcc. You seem to be discussing a different compiler. I don't think my suggestions for incremental improvement are relevant to creating your compiler: they don't help, and they don't hurt. Perhaps somebody else has something to say about this, but I don't. I'm a practical guy: I compile code with the compiler I have, not the compiler I might want or wish to have. Ian
