[Mesa-dev] [PATCH 9/9] anv: Enable UBO pushing

[Jason Ekstrand]

Push constants on Intel hardware are significantly more performant than
pull constants.  Since most Vulkan applications don't actively use push
constants on Vulkan or at least don't use it heavily, we're pulling way
more than we should be.  By enabling pushing chunks of UBOs we can get
rid of a lot of those pulls.

On my SKL GT4e, this improves the performance of Dota 2 and Talos by
around 2.5% and improves Aztec Ruins by around 2%.

Reviewed-by: Jordan Justen <jordan.l.justen at intel.com>
---
 src/intel/vulkan/anv_device.c   | 1 +
 src/intel/vulkan/anv_pipeline.c | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/src/intel/vulkan/anv_device.c b/src/intel/vulkan/anv_device.c
index 013823e..a9364b5 100644
--- a/src/intel/vulkan/anv_device.c
+++ b/src/intel/vulkan/anv_device.c
@@ -419,6 +419,7 @@ anv_physical_device_init(struct anv_physical_device *device,
    device->compiler->shader_debug_log = compiler_debug_log;
    device->compiler->shader_perf_log = compiler_perf_log;
    device->compiler->supports_pull_constants = false;
+   device->compiler->constant_buffer_0_is_relative = true;
 
    isl_device_init(&device->isl_dev, &device->info, swizzled);
 
diff --git a/src/intel/vulkan/anv_pipeline.c b/src/intel/vulkan/anv_pipeline.c
index cf2079d..f2d4d113 100644
--- a/src/intel/vulkan/anv_pipeline.c
+++ b/src/intel/vulkan/anv_pipeline.c
@@ -389,6 +389,9 @@ anv_pipeline_compile(struct anv_pipeline *pipeline,
                      struct brw_stage_prog_data *prog_data,
                      struct anv_pipeline_bind_map *map)
 {
+   const struct brw_compiler *compiler =
+      pipeline->device->instance->physicalDevice.compiler;
+
    nir_shader *nir = anv_shader_compile_to_nir(pipeline, mem_ctx,
                                                module, entrypoint, stage,
                                                spec_info);
@@ -438,6 +441,9 @@ anv_pipeline_compile(struct anv_pipeline *pipeline,
    if (pipeline->layout)
       anv_nir_apply_pipeline_layout(pipeline, nir, prog_data, map);
 
+   if (stage != MESA_SHADER_COMPUTE)
+      brw_nir_analyze_ubo_ranges(compiler, nir, prog_data->ubo_ranges);
+
    assert(nir->num_uniforms == prog_data->nr_params * 4);
 
    return nir;
-- 
2.5.0.400.gff86faf