Module: Mesa Branch: main Commit: 2717499c91d4b942e7c1f2024de4a8e18ec03cd7 URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=2717499c91d4b942e7c1f2024de4a8e18ec03cd7
Author: Danylo Piliaiev <[email protected]> Date: Tue Oct 10 14:55:26 2023 +0200 tu: Disable preamble push consts when they are not used It's a common case for Zink which has to declare push consts in pipeline layout, even if they are not actually used in shaders, due to the compatibility rules. Signed-off-by: Danylo Piliaiev <[email protected]> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25641> --- src/freedreno/vulkan/tu_shader.cc | 42 ++++++++++++++++++++++++++++++++------- 1 file changed, 35 insertions(+), 7 deletions(-) diff --git a/src/freedreno/vulkan/tu_shader.cc b/src/freedreno/vulkan/tu_shader.cc index a032e0a8e3d..2179a64f8e9 100644 --- a/src/freedreno/vulkan/tu_shader.cc +++ b/src/freedreno/vulkan/tu_shader.cc @@ -701,14 +701,48 @@ gather_push_constants(nir_shader *shader, struct tu_shader *tu_shader) align(max, 16) / 4 - tu_shader->const_state.push_consts.lo; } +static bool +shader_uses_push_consts(nir_shader *shader) +{ + nir_foreach_function_impl (impl, shader) { + nir_foreach_block (block, impl) { + nir_foreach_instr_safe (instr, block) { + if (instr->type != nir_instr_type_intrinsic) + continue; + + nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr); + if (intrin->intrinsic == nir_intrinsic_load_push_constant) + return true; + } + } + } + return false; +} + static bool tu_lower_io(nir_shader *shader, struct tu_device *dev, struct tu_shader *tu_shader, const struct tu_pipeline_layout *layout, unsigned *reserved_consts_vec4_out) { - if (tu_shader->const_state.push_consts.type == IR3_PUSH_CONSTS_PER_STAGE) + tu_shader->const_state.push_consts = (struct tu_push_constant_range) { + .lo = 0, + .dwords = layout->push_constant_size / 4, + .type = tu_push_consts_type(layout, dev->compiler), + }; + + if (tu_shader->const_state.push_consts.type == IR3_PUSH_CONSTS_PER_STAGE) { gather_push_constants(shader, tu_shader); + } else if (tu_shader->const_state.push_consts.type == + IR3_PUSH_CONSTS_SHARED_PREAMBLE) { + /* Disable pushing constants for this stage if none were loaded in the + * shader. If all stages don't load their declared push constants, as + * is often the case under zink, then we could additionally skip + * emitting REG_A7XX_HLSQ_SHARED_CONSTS_IMM entirely. + */ + if (!shader_uses_push_consts(shader)) + tu_shader->const_state.push_consts = (struct tu_push_constant_range) {}; + } struct tu_const_state *const_state = &tu_shader->const_state; unsigned reserved_consts_vec4 = @@ -2271,12 +2305,6 @@ tu_shader_create(struct tu_device *dev, nir->info.stage == MESA_SHADER_GEOMETRY) tu_gather_xfb_info(nir, &so_info); - shader->const_state.push_consts = (struct tu_push_constant_range) { - .lo = 0, - .dwords = layout->push_constant_size / 4, - .type = tu_push_consts_type(layout, dev->compiler), - }; - unsigned reserved_consts_vec4 = 0; NIR_PASS_V(nir, tu_lower_io, dev, shader, layout, &reserved_consts_vec4);
