[Mesa-dev] [PATCH 2/4] anv/apply_dynamic_offsets: Use rewrite_src instead of a regular assignment

[Michael Schellenberger Costa]

Hi Jason,

Am 19.05.2016 um 06:42 schrieb Jason Ekstrand:
> Originally we removed the instruction, changed the source, and then
> re-inserted it.  This works, but nir_instr_rewrite_src is a bit more
> obviously correct.
> ---
>  src/intel/vulkan/anv_nir_apply_dynamic_offsets.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/src/intel/vulkan/anv_nir_apply_dynamic_offsets.c b/src/intel/vulkan/anv_nir_apply_dynamic_offsets.c
> index 6a28953..a7ed3e5 100644
> --- a/src/intel/vulkan/anv_nir_apply_dynamic_offsets.c
> +++ b/src/intel/vulkan/anv_nir_apply_dynamic_offsets.c
> @@ -80,9 +80,10 @@ apply_dynamic_offsets_block(nir_block *block, nir_builder *b,
>        nir_ssa_dest_init(&offset_load->instr, &offset_load->dest, 2, 32, NULL);
>        nir_builder_instr_insert(b, &offset_load->instr);
>  
> -      nir_src *offset_src = nir_get_io_offset_src(intrin);
I think you didnt want to remove *offset_src here, given that it is used
below and reintroduced in the next patch?
--Michael
> -      nir_ssa_def *new_offset = nir_iadd(b, offset_src->ssa,
> +      nir_ssa_def *new_offset = nir_iadd(b, nir_ssa_for_src(*offset_src),
>                                           &offset_load->dest.ssa);
> +      nir_instr_rewrite_src(&intrin->instr, nir_get_io_offset_src(intrin),
> +                            nir_src_for_ssa(new_offset));
>  
>        /* In order to avoid out-of-bounds access, we predicate */
>        nir_ssa_def *pred = nir_uge(b, nir_channel(b, &offset_load->dest.ssa, 1),
> @@ -92,7 +93,6 @@ apply_dynamic_offsets_block(nir_block *block, nir_builder *b,
>        nir_cf_node_insert(b->cursor, &if_stmt->cf_node);
>  
>        nir_instr_remove(&intrin->instr);
> -      *offset_src = nir_src_for_ssa(new_offset);
>        nir_instr_insert_after_cf_list(&if_stmt->then_list, &intrin->instr);
>  
>        if (intrin->intrinsic != nir_intrinsic_store_ssbo) {
>