[Mesa-dev] [PATCH 1/6] anv/pipeline: Translate vulkan_resource_index to a constant when possible

[Jason Ekstrand]

We want to call brw_nir_analyze_ubo_ranges immedately after
anv_nir_apply_pipeline_layout and it badly wants constants.  We could
run an optimization step and let constant folding do it but that's way
more expensive than needed.  It's really easy to just handle constants
in apply_pipeline_layout.
---
 src/intel/vulkan/anv_nir_apply_pipeline_layout.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/src/intel/vulkan/anv_nir_apply_pipeline_layout.c b/src/intel/vulkan/anv_nir_apply_pipeline_layout.c
index f8d8164..4f7680b 100644
--- a/src/intel/vulkan/anv_nir_apply_pipeline_layout.c
+++ b/src/intel/vulkan/anv_nir_apply_pipeline_layout.c
@@ -116,12 +116,19 @@ lower_res_index_intrinsic(nir_intrinsic_instr *intrin,
    uint32_t array_size =
       state->layout->set[set].layout->binding[binding].array_size;
 
-   nir_ssa_def *block_index = nir_ssa_for_src(b, intrin->src[0], 1);
+   nir_const_value *const_block_index = nir_src_as_const_value(intrin->src[0]);
 
-   if (state->add_bounds_checks)
-      block_index = nir_umin(b, block_index, nir_imm_int(b, array_size - 1));
+   nir_ssa_def *block_index;
+   if (const_block_index) {
+      block_index = nir_imm_int(b, surface_index + const_block_index->u32[0]);
+   } else {
+      block_index = nir_ssa_for_src(b, intrin->src[0], 1);
 
-   block_index = nir_iadd(b, nir_imm_int(b, surface_index), block_index);
+      if (state->add_bounds_checks)
+         block_index = nir_umin(b, block_index, nir_imm_int(b, array_size - 1));
+
+      block_index = nir_iadd(b, nir_imm_int(b, surface_index), block_index);
+   }
 
    assert(intrin->dest.is_ssa);
    nir_ssa_def_rewrite_uses(&intrin->dest.ssa, nir_src_for_ssa(block_index));
-- 
2.5.0.400.gff86faf