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List:       mesa3d-dev
Subject:    Re: [Mesa-dev] [PATCH 1/6] r600g: Add no_merge_inst_groups flag
From:       Tom Stellard <thomas.stellard () amd ! com>
Date:       2012-04-30 13:30:40
Message-ID: 20120430133040.GA18629 () L7-CNU1252LKR-172027226155 ! amd ! com
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On Thu, Apr 26, 2012 at 04:53:58PM +0200, Christian König wrote:
> On 26.04.2012 16:40, Tom Stellard wrote:
> > On Thu, Apr 26, 2012 at 08:46:52AM -0400, Tom Stellard wrote:
> > > Setting this flag will skip the merge_inst_groups() function.
> > > ---
> > > src/gallium/drivers/r600/r600_asm.c |    3 ++-
> > > src/gallium/drivers/r600/r600_asm.h |   10 ++++++++++
> > > 2 files changed, 12 insertions(+), 1 deletions(-)
> > > 
> > > diff --git a/src/gallium/drivers/r600/r600_asm.c \
> > > b/src/gallium/drivers/r600/r600_asm.c index 0ecca36..5f83879 100644
> > > --- a/src/gallium/drivers/r600/r600_asm.c
> > > +++ b/src/gallium/drivers/r600/r600_asm.c
> > > @@ -1034,6 +1034,7 @@ static int merge_inst_groups(struct r600_bytecode *bc, \
> > > struct r600_bytecode_alu  int have_mova = 0, have_rel = 0;
> > > 	int max_slots = bc->chip_class == CAYMAN ? 4 : 5;
> > > 
> > > +	assert(!bc->no_merge_inst_groups);
> > > 	r = assign_alu_units(bc, alu_prev, prev);
> > > 	if (r)
> > > 		return r;
> > > @@ -1481,7 +1482,7 @@ int r600_bytecode_add_alu_type(struct r600_bytecode *bc, \
> > > const struct r600_bytec  if (r)
> > > 			return r;
> > > 
> > > -		if (bc->cf_last->prev_bs_head) {
> > > +		if (!bc->no_merge_inst_groups&&  bc->cf_last->prev_bs_head) {
> > > 			r = merge_inst_groups(bc, slots, bc->cf_last->prev_bs_head);
> > > 			if (r)
> > > 				return r;
> > > diff --git a/src/gallium/drivers/r600/r600_asm.h \
> > > b/src/gallium/drivers/r600/r600_asm.h index 5790ead..86d44d3 100644
> > > --- a/src/gallium/drivers/r600/r600_asm.h
> > > +++ b/src/gallium/drivers/r600/r600_asm.h
> > > @@ -205,6 +205,16 @@ struct r600_bytecode {
> > > 	unsigned	ar_reg;
> > > 	unsigned        ar_handling;
> > > 	unsigned        r6xx_nop_after_rel_dst;
> > > +
> > > +	/* Setting this bit will prevent the r600 assembler from trying to
> > > +	 * merge instruction groups.  This is necessary for compute shaders,
> > > +	 * because the CF_ALLOC_EXPORT_WORD0_RAT instructions expects the index
> > > +	 * values to be in the X, Y, and Z channels depending on the
> > > +	 * dimension of the surface.  The merge_inst_groups function will move
> > > +	 * these values around to the wrong channels and the RAT read or write
> > > +	 * will fail.
> > > +	 */
> > vadimg has pointed out on IRC that this comment is wrong, and the
> > merge_inst_groups function won't rewrite the destination channels.
> > 
> > I think this patch might still be useful, so I'll just drop this comment
> > from the final version.
> I would rather prefer to not do workarounds like this, but rather
> teach merge_instruction groups the reason why something can't be
> merged.

OK, I'll drop this patch.

-Tom

> 
> Christian.
> 
> > 
> > -Tom
> > 
> > > +	unsigned			no_merge_inst_groups;
> > > };
> > > 
> > > /* eg_asm.c */
> > > -- 
> > > 1.7.7.6
> > > 
> > > 
> > _______________________________________________
> > mesa-dev mailing list
> > mesa-dev@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/mesa-dev
> > 
> 
> 

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