[Mesa-dev] [PATCH] nv50/ir: convert an ATOM.EXCH without a destination into a store

[Samuel Pitoiset]

Can you double check what the blob do in this scenario?

On 02/10/2017 07:59 AM, Ilia Mirkin wrote:
> On SM35 there does not appear to be a way to emit a ATOM.EXCH with a
> null destination. This should be functionally equivalent to a plain
> store however, so just do that.
>
> Fixes GL45-CTS.compute_shader.atomic-case2 on SM35.
>
> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
> ---
>  src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> index d79e87d..79403c9 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> @@ -3549,6 +3549,11 @@ DeadCodeElim::visit(BasicBlock *bb)
>               i->op == OP_SUREDP ||
>               i->op == OP_SUREDB) {
>              i->setDef(0, NULL);
> +            if (i->op == OP_ATOM && i->subOp == NV50_IR_SUBOP_ATOM_EXCH) {
> +               i->cache = CACHE_CV;
> +               i->op = OP_STORE;
> +               i->subOp = 0;
> +            }
>           } else if (i->op == OP_LOAD && i->subOp == NV50_IR_SUBOP_LOAD_LOCKED) {
>              i->setDef(0, i->getDef(1));
>              i->setDef(1, NULL);
>