From 0539f26065293f4323345a7014472b1c0a5a776a Mon Sep 17 00:00:00 2001
From: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Date: Thu, 22 Jan 2026 20:15:08 +0200
Subject: [PATCH] brw: track push constants shader stats

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Felix DeGrood <felix.j.degrood@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/39451>
---
 src/intel/compiler/brw/brw_generator.cpp | 43 ++++++++++++++++++++++++
 src/util/shader_stats.xml                |  6 ++++
 2 files changed, 49 insertions(+)

diff --git a/src/intel/compiler/brw/brw_generator.cpp b/src/intel/compiler/brw/brw_generator.cpp
index 28b14abc9eb..2e92c487e33 100644
--- a/src/intel/compiler/brw/brw_generator.cpp
+++ b/src/intel/compiler/brw/brw_generator.cpp
@@ -1449,6 +1449,49 @@ brw_generator::generate_code(const brw_shader &s,
       stats->grf_registers = devinfo->ver >= 30 ? s.grf_used : 0;
       stats->scheduler_mode = shader_stats.scheduler_mode;
 
+      switch (stage) {
+      case MESA_SHADER_VERTEX:
+      case MESA_SHADER_TESS_CTRL:
+      case MESA_SHADER_TESS_EVAL:
+      case MESA_SHADER_GEOMETRY:
+      case MESA_SHADER_FRAGMENT:
+         stats->push_constant_ranges = 0;
+         stats->push_constant_registers = 0;
+         for (uint32_t i = 0; i < 4; i++) {
+            stats->push_constant_ranges += prog_data->push_sizes[i] != 0;
+            stats->push_constant_registers +=
+               DIV_ROUND_UP(prog_data->push_sizes[i], reg_unit(devinfo) * REG_SIZE);
+         }
+         break;
+
+      case MESA_SHADER_COMPUTE:
+      case MESA_SHADER_KERNEL:
+         /* Pre Gfx12.5, there is only one push constant buffer for compute
+          * shaders, post Gfx12.5 the shader has to pull the constant data.
+          */
+         stats->push_constant_ranges =
+            devinfo->verx10 < 125 ? (prog_data->push_sizes[0] != 0) : 0;
+         stats->push_constant_registers =
+            devinfo->verx10 < 125 ?
+            DIV_ROUND_UP(prog_data->push_sizes[0], reg_unit(devinfo) * REG_SIZE) : 0;
+         break;
+
+      case MESA_SHADER_MESH:
+      case MESA_SHADER_TASK:
+      case MESA_SHADER_RAYGEN:
+      case MESA_SHADER_ANY_HIT:
+      case MESA_SHADER_CLOSEST_HIT:
+      case MESA_SHADER_MISS:
+      case MESA_SHADER_INTERSECTION:
+      case MESA_SHADER_CALLABLE:
+         stats->push_constant_ranges = 0;
+         stats->push_constant_registers = 0;
+         break;
+
+      default:
+         UNREACHABLE("invalid stage");
+      }
+
       /* Report the max dispatch width only on the smallest SIMD variant.
        *
        * XXX: SIMD8 is not the smallest on Xe2. This logic should be adjusted.
diff --git a/src/util/shader_stats.xml b/src/util/shader_stats.xml
index 340f72fbe42..3318cdf2cdc 100644
--- a/src/util/shader_stats.xml
+++ b/src/util/shader_stats.xml
@@ -172,6 +172,12 @@
          <stat name="GRF registers">
             Number of GRF registers required by the shader.
          </stat>
+         <stat name="Push constant ranges">
+            Number of push constants ranges provided to the shader.
+         </stat>
+         <stat name="Push constant registers">
+            Number of GRF registers in the payload registers dedicated to constants.
+         </stat>
          <stat name="Max dispatch width" more="better">
             Largest SIMD dispatch width.
          </stat>