[Mesa-dev] [PATCH 5/9] i965/cs: Add a binding table entry for gl_NumWorkGroups

[Jordan Justen]

If glDispatchComputeIndirect is used, then the value for this variable
must be read from the indirect BO.

To allow the same generated code to support indirect and
glDispatchCompute, we will also setup a BO for the number of work
groups using the intel_upload_data mechanism. This will only be
required if the gl_NumWorkGroups variable is accessed.

Signed-off-by: Jordan Justen <jordan.l.justen at intel.com>
---
 src/mesa/drivers/dri/i965/brw_context.h | 11 ++++++++++-
 src/mesa/drivers/dri/i965/brw_fs.cpp    | 20 +++++++++++++++++---
 src/mesa/drivers/dri/i965/brw_fs.h      |  3 ++-
 3 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_context.h b/src/mesa/drivers/dri/i965/brw_context.h
index 349c49d..481f964 100644
--- a/src/mesa/drivers/dri/i965/brw_context.h
+++ b/src/mesa/drivers/dri/i965/brw_context.h
@@ -499,6 +499,14 @@ struct brw_cs_prog_data {
    unsigned local_size[3];
    unsigned simd_size;
    bool uses_barrier;
+
+   struct {
+      /** @{
+       * surface indices the CS-specific surfaces
+       */
+      uint32_t work_groups_start;
+      /** @} */
+   } binding_table;
 };
 
 /**
@@ -748,7 +756,8 @@ struct brw_vs_prog_data {
                             12 + /* ubo */                              \
                             BRW_MAX_ABO +                               \
                             BRW_MAX_IMAGES +                            \
-                            2 /* shader time, pull constants */)
+                            2 + /* shader time, pull constants */       \
+                            1 /* cs num work groups */)
 
 #define SURF_INDEX_GEN6_SOL_BINDING(t) (t)
 
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index a8f5520..758fd4f 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -4749,7 +4749,7 @@ fs_visitor::setup_cs_payload()
 }
 
 void
-fs_visitor::assign_binding_table_offsets()
+fs_visitor::assign_fs_binding_table_offsets()
 {
    assert(stage == MESA_SHADER_FRAGMENT);
    brw_wm_prog_data *prog_data = (brw_wm_prog_data*) this->prog_data;
@@ -4766,6 +4766,20 @@ fs_visitor::assign_binding_table_offsets()
 }
 
 void
+fs_visitor::assign_cs_binding_table_offsets()
+{
+   assert(stage == MESA_SHADER_COMPUTE);
+   brw_cs_prog_data *prog_data = (brw_cs_prog_data*) this->prog_data;
+   uint32_t next_binding_table_offset = 0;
+
+   /* May not be used if the gl_NumWorkGroups variable is not accessed. */
+   prog_data->binding_table.work_groups_start = next_binding_table_offset;
+   next_binding_table_offset++;
+
+   assign_common_binding_table_offsets(next_binding_table_offset);
+}
+
+void
 fs_visitor::calculate_register_pressure()
 {
    invalidate_live_intervals();
@@ -5019,7 +5033,7 @@ fs_visitor::run_fs(bool do_rep_send)
 
    sanity_param_count = prog->Parameters->NumParameters;
 
-   assign_binding_table_offsets();
+   assign_fs_binding_table_offsets();
 
    if (devinfo->gen >= 6)
       setup_payload_gen6();
@@ -5107,7 +5121,7 @@ fs_visitor::run_cs()
 
    sanity_param_count = prog->Parameters->NumParameters;
 
-   assign_common_binding_table_offsets(0);
+   assign_cs_binding_table_offsets();
 
    setup_cs_payload();
 
diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
index 50ce415..a8b6726 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -128,7 +128,8 @@ public:
    bool run_cs();
    void optimize();
    void allocate_registers();
-   void assign_binding_table_offsets();
+   void assign_fs_binding_table_offsets();
+   void assign_cs_binding_table_offsets();
    void setup_payload_gen4();
    void setup_payload_gen6();
    void setup_vs_payload();
-- 
2.5.1