Mesa (main): anv/pipeline: Get rid of sample_shading_enable

[GitLab Mirror]

Module: Mesa
Branch: main
Commit: 288a670f17be32bc19ef0b07d140b5a2926cf4c3
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=288a670f17be32bc19ef0b07d140b5a2926cf4c3

Author: Jason Ekstrand <jason at jlekstrand.net>
Date:   Tue Dec 14 12:17:53 2021 -0600

anv/pipeline: Get rid of sample_shading_enable

Putting it in the pipeline is a bit of a lie.  We no longer need it for
nir_lower_wpos_center. The only other user is pipeline_has_coarse_pixel
and that is used to build the shader key which we construct before we've
processed any NIR so we don't have accurate information at that time
anyway.  Instead, look at ms_info->sampleShadingEnable directly in
pipeline_has_coarse_pixel and trust the back-end to deal with disabling
coarse when we need per-sample dispatch.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14198>

---

 src/intel/vulkan/anv_pipeline.c | 47 +++++++++++++++++++++++++++++------------
 src/intel/vulkan/anv_private.h  |  1 -
 2 files changed, 33 insertions(+), 15 deletions(-)

diff --git a/src/intel/vulkan/anv_pipeline.c b/src/intel/vulkan/anv_pipeline.c
index 0ece06c92d8..f3e11b3701b 100644
--- a/src/intel/vulkan/anv_pipeline.c
+++ b/src/intel/vulkan/anv_pipeline.c
@@ -475,9 +475,40 @@ populate_gs_prog_key(const struct intel_device_info *devinfo,
 
 static bool
 pipeline_has_coarse_pixel(const struct anv_graphics_pipeline *pipeline,
+                          const VkPipelineMultisampleStateCreateInfo *ms_info,
                           const VkPipelineFragmentShadingRateStateCreateInfoKHR *fsr_info)
 {
-   if (pipeline->sample_shading_enable)
+   /* The Vulkan 1.2.199 spec says:
+    *
+    *    "If any of the following conditions are met, Cxy' must be set to
+    *    {1,1}:
+    *
+    *     * If Sample Shading is enabled.
+    *     * [...]"
+    *
+    * And "sample shading" is defined as follows:
+    *
+    *    "Sample shading is enabled for a graphics pipeline:
+    *
+    *     * If the interface of the fragment shader entry point of the
+    *       graphics pipeline includes an input variable decorated with
+    *       SampleId or SamplePosition. In this case minSampleShadingFactor
+    *       takes the value 1.0.
+    *
+    *     * Else if the sampleShadingEnable member of the
+    *       VkPipelineMultisampleStateCreateInfo structure specified when
+    *       creating the graphics pipeline is set to VK_TRUE. In this case
+    *       minSampleShadingFactor takes the value of
+    *       VkPipelineMultisampleStateCreateInfo::minSampleShading.
+    *
+    *    Otherwise, sample shading is considered disabled."
+    *
+    * The first bullet above is handled by the back-end compiler because those
+    * inputs both force per-sample dispatch.  The second bullet is handled
+    * here.  Note that this sample shading being enabled has nothing to do
+    * with minSampleShading.
+    */
+   if (ms_info && ms_info->sampleShadingEnable)
       return false;
 
    /* Not dynamic & not specified for the pipeline. */
@@ -554,7 +585,7 @@ populate_wm_prog_key(const struct anv_graphics_pipeline *pipeline,
 
    key->coarse_pixel =
       device->vk.enabled_extensions.KHR_fragment_shading_rate &&
-      pipeline_has_coarse_pixel(pipeline, fsr_info);
+      pipeline_has_coarse_pixel(pipeline, ms_info, fsr_info);
 }
 
 static void
@@ -795,13 +826,6 @@ anv_pipeline_lower_nir(struct anv_pipeline *pipeline,
    nir_shader *nir = stage->nir;
 
    if (nir->info.stage == MESA_SHADER_FRAGMENT) {
-      /* Check if sample shading is enabled in the shader and toggle
-       * it on for the pipeline independent if sampleShadingEnable is set.
-       */
-      nir_shader_gather_info(nir, nir_shader_get_entrypoint(nir));
-      if (nir->info.fs.uses_sample_shading)
-         anv_pipeline_to_graphics(pipeline)->sample_shading_enable = true;
-
       NIR_PASS_V(nir, nir_lower_wpos_center);
       NIR_PASS_V(nir, nir_lower_input_attachments,
                  &(nir_input_attachment_options) {
@@ -2428,11 +2452,6 @@ anv_graphics_pipeline_init(struct anv_graphics_pipeline *pipeline,
                            PIPELINE_RASTERIZATION_DEPTH_CLIP_STATE_CREATE_INFO_EXT);
    pipeline->depth_clip_enable = clip_info ? clip_info->depthClipEnable : !pipeline->depth_clamp_enable;
 
-   pipeline->sample_shading_enable =
-      !pCreateInfo->pRasterizationState->rasterizerDiscardEnable &&
-      pCreateInfo->pMultisampleState &&
-      pCreateInfo->pMultisampleState->sampleShadingEnable;
-
    result = anv_pipeline_compile_graphics(pipeline, cache, pCreateInfo);
    if (result != VK_SUCCESS) {
       anv_pipeline_finish(&pipeline->base, device, alloc);
diff --git a/src/intel/vulkan/anv_private.h b/src/intel/vulkan/anv_private.h
index 749a92d4014..c58bd9491e0 100644
--- a/src/intel/vulkan/anv_private.h
+++ b/src/intel/vulkan/anv_private.h
@@ -3348,7 +3348,6 @@ struct anv_graphics_pipeline {
    bool                                         stencil_test_enable;
    bool                                         depth_clamp_enable;
    bool                                         depth_clip_enable;
-   bool                                         sample_shading_enable;
    bool                                         kill_pixel;
    bool                                         depth_bounds_test_enable;
    bool                                         force_fragment_thread_dispatch;