Re: Some thoughts about steerring commitee work

[Eric Botcazou <ebotcazou at libertysurf dot fr>]

> No, GCC hit a fundamental wall because its backend was not modern.
> The code we generate out of tree-ssa is in general, as good or better
> than other compilers generate out of their middle ends.
>
> The problem remaining is that they have much better backends then us.
>
> Until dataflow, *nobody* had done any sort of major undertaking to
> make the *entire* backend actually modern in any way, shape or form.

I presume that "backend" means the RTL part of the compiler, right?  So we 
should focus our efforts on the low-level part of the compiler, rather than 
on the high-level part?  E.g the register allocator?

> Our backends have done roughly the same good/bad job of generating
> code since, well, forever.  Until that changes, you will see that the
> only performance improvements you get in the general case are things
> that the backend was too dumb to get in the first place (IE loads,
> stores)

Note that Tree-SSA was supposed to butcher the RTL optimizers and replace them 
with something less "crappy" though.

-- 
Eric Botcazou