[Mesa-dev] [PATCH v2 2/4] anv/apply_dynamic_offsets: Use rewrite_src instead of a regular assignment

[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 | 9 +++++----
 1 file changed, 5 insertions(+), 4 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..84fed0a 100644
--- a/src/intel/vulkan/anv_nir_apply_dynamic_offsets.c
+++ b/src/intel/vulkan/anv_nir_apply_dynamic_offsets.c
@@ -81,18 +81,19 @@ apply_dynamic_offsets_block(nir_block *block, nir_builder *b,
       nir_builder_instr_insert(b, &offset_load->instr);
 
       nir_src *offset_src = nir_get_io_offset_src(intrin);
-      nir_ssa_def *new_offset = nir_iadd(b, offset_src->ssa,
-                                         &offset_load->dest.ssa);
+      nir_ssa_def *old_offset = nir_ssa_for_src(b, *offset_src, 1);
+      nir_ssa_def *new_offset = nir_iadd(b, old_offset, &offset_load->dest.ssa);
+      nir_instr_rewrite_src(&intrin->instr, offset_src,
+                            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),
-                                  offset_src->ssa);
+                                  old_offset);
       nir_if *if_stmt = nir_if_create(b->shader);
       if_stmt->condition = nir_src_for_ssa(pred);
       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) {
-- 
2.5.0.400.gff86faf