Re: Commit: RL78: Include tree-pass.h
> The issue is that using the plugin interface makes breakage only > detectable when you are able to test a target, not by merely > building it. You just described *most* of the bugs I have to deal with.
Re: Commit: RL78: Include tree-pass.h
On Wed, Aug 8, 2012 at 5:29 PM, Richard Henderson wrote: > On 08/08/2012 07:19 AM, Ian Lance Taylor wrote: >>> > I was suggesting to for example register a 2nd mdreorg-like pass and >>> > add a 2nd target hook. regstack should get the same treatment. >> If the mechanism is a proliferation of mdreorg passes in every place >> we want a target-specific pass, that is fine with me. > > I think it makes much more sense to edit the pass ordering from > the backend, rather than hooks upon hooks upon hooks. > > Since the plugin interface exists, we might as well use it. The issue is that using the plugin interface makes breakage only detectable when you are able to test a target, not by merely building it. That's bad (of course only for those weirdo targets). We should _at least_ provide an interface to internals that for example use the address of the pass structure for pass placement instead of just the dump file name. Richard. > > r~
Re: Commit: RL78: Include tree-pass.h
> But we should definitely have a way to register machine dependent > passes, and what's wrong with the plugin interface? IIRC I asked about how to schedule that pass when I wrote it, and "use the plugin API" was the recommendation. Some background... The RL78 devirtualization pass is *not* a reorg pass, it has to happen after reload but before debug info is set up. The RL78 does not have a consistent register set or addressing scheme, GCC cannot practically support it. So RL78 uses a virtual register set and machine description until after reload, then copy data in and out of the virtual registers to physical registers depending on the operations required. The only way to get decent performance and reasonable debugging is to do that pass as soon after reload as possible, so the remaining optimizations can work with real registers. Basically, after the RL78 devirtualization pass, the RL78 is a completely different target machine.
Re: Commit: RL78: Include tree-pass.h
On 08/08/2012 07:19 AM, Ian Lance Taylor wrote: >> > I was suggesting to for example register a 2nd mdreorg-like pass and >> > add a 2nd target hook. regstack should get the same treatment. > If the mechanism is a proliferation of mdreorg passes in every place > we want a target-specific pass, that is fine with me. I think it makes much more sense to edit the pass ordering from the backend, rather than hooks upon hooks upon hooks. Since the plugin interface exists, we might as well use it. r~
Re: Commit: RL78: Include tree-pass.h
On Wed, Aug 8, 2012 at 7:11 AM, Richard Guenther wrote: > On Wed, Aug 8, 2012 at 4:06 PM, Ian Lance Taylor wrote: >> On Wed, Aug 8, 2012 at 7:03 AM, Richard Guenther >> wrote: >> >>> I don't think we really want that (machine dependent passes). It seems >>> we cannot get away with it (so we have mdreorg). Allowing (some) >>> flexibility >>> where to put mdreorg is ok, using two different mechanisms (mdreorg and >>> a "plugin") sounds odd and is IMHO bad for consistency. >> >> I think we definitely want machine dependent passes. E.g., reg-stack >> should be one. The passes should live by normal rules, they shouldn't >> be like mdreorg. > > What is "like mdreorg"? That it is a pass centrally registered, > called "mdreorg" > that calls a target hook which happens to implement the pass? regstack > is controlled by a target macro and is centrally registered, too. > >> I don't really care about the mechanism as long as it exists. > > I was suggesting to for example register a 2nd mdreorg-like pass and > add a 2nd target hook. regstack should get the same treatment. If the mechanism is a proliferation of mdreorg passes in every place we want a target-specific pass, that is fine with me. Ian
Re: Commit: RL78: Include tree-pass.h
On Wed, Aug 8, 2012 at 4:06 PM, Ian Lance Taylor wrote: > On Wed, Aug 8, 2012 at 7:03 AM, Richard Guenther > wrote: > >> I don't think we really want that (machine dependent passes). It seems >> we cannot get away with it (so we have mdreorg). Allowing (some) flexibility >> where to put mdreorg is ok, using two different mechanisms (mdreorg and >> a "plugin") sounds odd and is IMHO bad for consistency. > > I think we definitely want machine dependent passes. E.g., reg-stack > should be one. The passes should live by normal rules, they shouldn't > be like mdreorg. What is "like mdreorg"? That it is a pass centrally registered, called "mdreorg" that calls a target hook which happens to implement the pass? regstack is controlled by a target macro and is centrally registered, too. > I don't really care about the mechanism as long as it exists. I was suggesting to for example register a 2nd mdreorg-like pass and add a 2nd target hook. regstack should get the same treatment. Exposing machine-dependent passes in the global pass schedule makes it easier to figure what you break - as I saw the RL78 use I wondered when I ever grepped for the pass dump-file name in arch specific dirs when changing that ... (never). Richard. > Ian
Re: Commit: RL78: Include tree-pass.h
On Wed, Aug 8, 2012 at 7:03 AM, Richard Guenther wrote: > I don't think we really want that (machine dependent passes). It seems > we cannot get away with it (so we have mdreorg). Allowing (some) flexibility > where to put mdreorg is ok, using two different mechanisms (mdreorg and > a "plugin") sounds odd and is IMHO bad for consistency. I think we definitely want machine dependent passes. E.g., reg-stack should be one. The passes should live by normal rules, they shouldn't be like mdreorg. I don't really care about the mechanism as long as it exists. Ian
Re: Commit: RL78: Include tree-pass.h
On Wed, Aug 8, 2012 at 3:35 PM, Ian Lance Taylor wrote: > On Wed, Aug 8, 2012 at 1:45 AM, Richard Guenther > wrote: >> On Wed, Aug 8, 2012 at 10:28 AM, Nick Clifton wrote: >>> Hi DJ, >>> >>> I am applying the following patch to the gcc mainline as an obvious >>> fix for the following problem building the RL78 backend: >>> >>> gcc/config/rl78/rl78.c:151:3: error: 'PASS_POS_INSERT_BEFORE' >>> undeclared here (not in a function) >> >> Err - you are inside the compiler and should not use plugin stuff to >> register your machine dependent pass. > > But we should definitely have a way to register machine dependent > passes, and what's wrong with the plugin interface? I don't think we really want that (machine dependent passes). It seems we cannot get away with it (so we have mdreorg). Allowing (some) flexibility where to put mdreorg is ok, using two different mechanisms (mdreorg and a "plugin") sounds odd and is IMHO bad for consistency. Richard. > Ian
Re: Commit: RL78: Include tree-pass.h
On Wed, Aug 8, 2012 at 1:45 AM, Richard Guenther wrote: > On Wed, Aug 8, 2012 at 10:28 AM, Nick Clifton wrote: >> Hi DJ, >> >> I am applying the following patch to the gcc mainline as an obvious >> fix for the following problem building the RL78 backend: >> >> gcc/config/rl78/rl78.c:151:3: error: 'PASS_POS_INSERT_BEFORE' undeclared >> here (not in a function) > > Err - you are inside the compiler and should not use plugin stuff to > register your machine dependent pass. But we should definitely have a way to register machine dependent passes, and what's wrong with the plugin interface? Ian
Re: Commit: RL78: Include tree-pass.h
On Wed, Aug 8, 2012 at 11:02 AM, nick clifton wrote: > Hi Richard, > > >> Err - you are inside the compiler and should not use plugin stuff to >> register your machine dependent pass. > > > Umm, OK, what is the correct method for registering target specific passes ? > (Ones that need to run at times other than TARGET_MACHINE_DEPENDENT_REORG). Have two machine_reorg passes with different target hooks. Or schedule it twice and have a target hook that specifies at which position it should actually run. Richard. > Cheers > Nick > >
Re: Commit: RL78: Include tree-pass.h
Hi Richard, Err - you are inside the compiler and should not use plugin stuff to register your machine dependent pass. Umm, OK, what is the correct method for registering target specific passes ? (Ones that need to run at times other than TARGET_MACHINE_DEPENDENT_REORG). Cheers Nick
Re: Commit: RL78: Include tree-pass.h
On Wed, Aug 8, 2012 at 10:28 AM, Nick Clifton wrote: > Hi DJ, > > I am applying the following patch to the gcc mainline as an obvious > fix for the following problem building the RL78 backend: > > gcc/config/rl78/rl78.c:151:3: error: 'PASS_POS_INSERT_BEFORE' undeclared > here (not in a function) Err - you are inside the compiler and should not use plugin stuff to register your machine dependent pass. > Cheers > Nick > > gcc/ChangeLog > 2012-08-08 Nick Clifton > > * config/rl78/rl78.c: Include tree-pass.h. > > Index: gcc/config/rl78/rl78.c > === > --- gcc/config/rl78/rl78.c (revision 190223) > +++ gcc/config/rl78/rl78.c (working copy) > @@ -48,6 +48,7 @@ > #include "langhooks.h" > #include "rl78-protos.h" > #include "dumpfile.h" > +#include "tree-pass.h" > > static inline bool is_interrupt_func (const_tree decl); > static inline bool is_brk_interrupt_func (const_tree decl);
