[Mesa-dev] [PATCH 1/2] radeonsi: Cache LLVMTargetMachine object in si_screen

[Tom Stellard]

On Tue, Jan 13, 2015 at 06:47:00PM +0900, Michel Dänzer wrote:
> On 07.01.2015 10:10, Michel Dänzer wrote:
> > On 07.01.2015 06:33, Tom Stellard wrote:
> >> On Wed, Dec 24, 2014 at 12:48:31PM +0900, Michel Dänzer wrote:
> >>> On 24.12.2014 02:49, Tom Stellard wrote:
> >>>> Rather than building a new one every compile.  This should reduce some
> >>>> of the overhead of compiling shaders.
> >>>
> >>> Thanks, though unfortunately it doesn't seem to make much difference for
> >>> piglit for me.
> >>>
> >>>
> >>>> One consequence of this change is that we lose the MachineInstrs dumps
> >>>> when dumping the shaders via R600_DEBUG.  The LLVM IR and assembly is
> >>>> still dumped, and if you still want to see the MachineInstr dump, you
> >>>> can run the dumped LLVM IR through llc.
> >>>
> >>> Sounds reasonable, but...
> >>>
> >>>
> >>>> @@ -503,5 +510,12 @@ struct pipe_screen *radeonsi_screen_create(struct radeon_winsys *ws)
> >>>>  	/* Create the auxiliary context. This must be done last. */
> >>>>  	sscreen->b.aux_context = sscreen->b.b.context_create(&sscreen->b.b, NULL);
> >>>>  
> >>>> +	/* Initialize LLVM TargetMachine */
> >>>> +	r600_target = radeon_llvm_get_r600_target();
> >>>> +	sscreen->tm = LLVMCreateTargetMachine(r600_target, "r600--",
> >>>> +				r600_get_llvm_processor_name(sscreen->b.family),
> >>>> +				"+DumpCode", LLVMCodeGenLevelDefault, LLVMRelocDefault,
> >>>> +				LLVMCodeModelDefault);
> >>>> +
> >>>>  	return &sscreen->b.b;
> >>>>  }
> >>>
> >>> ... since you pass "+DumpCode" here, the MachineInstrs are actually
> >>> always dumped unconditionally. With that fixed, this patch is
> >>>
> >>
> >> I've removed the MF.dump() call in the LLVM tree, so this won't happen.
> > 
> > That won't help people using LLVM 3.4 (or 3.5?), will it?
> 
> Tom, users of LLVM 3.4/5 get spammed by MachineInstr dumps with this
> change, right? Do you have a plan to address this?
> 

I disabled target machine caching for < LLVM 3.6, so this shouldn't be
an issue.

-Tom

> 
> -- 
> Earthling Michel Dänzer               |               http://www.amd.com
> Libre software enthusiast             |             Mesa and X developer