Re: [Sdcc-user] A better register allocator for the Z80

[Frieder F. <fri...@we...>]

Hi Philipp,

Am 10.01.2011 21:55, schrieb Philipp Klaus Krause:
> Am 10.01.2011 20:57, schrieb Maarten Brock:
>> Philipp,
> 
>> Why not just commit this to subversion? We are nowhere 
>> near a release so this should not hurt too much. And you 
>> even claim it passes all current regression tests. I see 
>> no reason to keep this separate.
> 
>> Maarten
> 
> There are some problems:
>
> ...
>
> 7) The underlying ideas are not accepted in the compiler construction
> community. I submitted a paper to the Compiler Construction 2010
> conference, which was rejected rather harshly: "[...] this paper will
> remain, yet another time, a purely theoretical paper with no influence
> on register allocation.", "[...] results will remain uncited or unused
> [...]", "[...] impractical for use in a real compiler.", "[...] the
> algorithm is only of theoretical value.", etc.

"[...] impractical for use in a real compiler."
would look like a problem. Is this just a statement?


Harsh wording sometimes is an indication for lack of argument.
The "yet another time" fragment might be an indication
that the reasoning has not been fair.
Tasks SDCC has to solve often have to fit into 64kByte
(with obviously the code size per function fitting
into _much_ less).
And there possibly (..) could be the fallback of:

OhHaveABreakMyNotYetPerfectNPHardRegisterAllocationCodeBurned \
MoreThan10ToThePowerOf7CPUCyclesForThisVeryFunctionIFeelBad \
AboutThatNPHardStuffWouldYouPleaseCompareMyAdmittedly \
SuboptimalResultsToTheOldFashionedRegisterAllocationCode \
AndEventuallyUseThat_UnlessTheUserWantsMeToPulverizeAnother \
10ToThePowerOf9CPUCyclesIWouldPreferToTackleTheNextFunctionNow


Greetings,
Frieder