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Re: Where does the time go?
Steven Bosscher wrote:
> The GIMPLE tuples work took man-years (note: plural). There was less
> code to convert and the process of conversion was easier, relatively,
> than the conversion of RTL would be. So your one person-year seems
> grossly underestimated.
I dunno. To get good project estimates, you have to break things down
into small enough subpieces that you have good confidence in the
estimates. I certainly don't claim a high level of confidence in my
estimate. But, it's a largely mechanical activity; we're not talking
about changing algorithms, but rather about changing data representations.
As to whether this is a better choice than working on GIMPLE back-ends,
I think that's unclear. There's no question that a GIMPLE back-end
would be prettier. I think it's a question of what your goals are. If
your goal is a faster compiler with less memory usage, I bet converting
RTL to a better representation is a faster path to that solution. If
your goal is to have one representation all the way through to ease
future maintenance and make it easier to do plugins at all stages of
compilation and so forth, then a better representation for RTL doesn't
really help you.
I'd accept either set of patches, if someone were to provide them.
--
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713