i965/vec4: Implement VS_OPCODE_GET_BUFFER_SIZE

Notice that Skylake needs to include a header in the sampler message
so it will need some tweaks to work there.

Signed-off-by: Samuel Iglesias Gonsalvez <[email protected]>
Reviewed-by: Kristian Høgsberg <[email protected]>

5 files changed, 44 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_defines.h b/src/mesa/drivers/dri/i965/brw_defines.h
index f0797985a19..0eada4fa380 100644
--- a/src/mesa/drivers/dri/i965/brw_defines.h
+++ b/src/mesa/drivers/dri/i965/brw_defines.h
@@ -1084,6 +1084,9 @@ enum opcode {
    VS_OPCODE_PULL_CONSTANT_LOAD,
    VS_OPCODE_PULL_CONSTANT_LOAD_GEN7,
    VS_OPCODE_SET_SIMD4X2_HEADER_GEN9,
+
+   VS_OPCODE_GET_BUFFER_SIZE,
+
    VS_OPCODE_UNPACK_FLAGS_SIMD4X2,
 
    /**
diff --git a/src/mesa/drivers/dri/i965/brw_shader.cpp b/src/mesa/drivers/dri/i965/brw_shader.cpp
index c311a038e4f..13771b7def0 100644
--- a/src/mesa/drivers/dri/i965/brw_shader.cpp
+++ b/src/mesa/drivers/dri/i965/brw_shader.cpp
@@ -745,6 +745,9 @@ brw_instruction_name(enum opcode op)
    case VS_OPCODE_SET_SIMD4X2_HEADER_GEN9:
       return "set_simd4x2_header_gen9";
 
+   case VS_OPCODE_GET_BUFFER_SIZE:
+      return "vs_get_buffer_size";
+
    case VS_OPCODE_UNPACK_FLAGS_SIMD4X2:
       return "unpack_flags_simd4x2";
 
diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp
index c6510453479..c61b38548f7 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp
@@ -332,6 +332,7 @@ vec4_visitor::implied_mrf_writes(vec4_instruction *inst)
    case SHADER_OPCODE_TG4:
    case SHADER_OPCODE_TG4_OFFSET:
    case SHADER_OPCODE_SAMPLEINFO:
+   case VS_OPCODE_GET_BUFFER_SIZE:
       return inst->header_size;
    default:
       unreachable("not reached");
diff --git a/src/mesa/drivers/dri/i965/brw_vec4.h b/src/mesa/drivers/dri/i965/brw_vec4.h
index de74ec9bb68..ed711902de4 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.h
+++ b/src/mesa/drivers/dri/i965/brw_vec4.h
@@ -560,6 +560,12 @@ private:
                                          struct brw_reg offset);
    void generate_set_simd4x2_header_gen9(vec4_instruction *inst,
                                          struct brw_reg dst);
+
+   void generate_get_buffer_size(vec4_instruction *inst,
+                                 struct brw_reg dst,
+                                 struct brw_reg src,
+                                 struct brw_reg index);
+
    void generate_unpack_flags(struct brw_reg dst);
 
    const struct brw_compiler *compiler;
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp b/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
index 05f20441adb..c7546070bf9 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
@@ -1033,6 +1033,32 @@ vec4_generator::generate_pull_constant_load(vec4_instruction *inst,
 }
 
 void
+vec4_generator::generate_get_buffer_size(vec4_instruction *inst,
+                                         struct brw_reg dst,
+                                         struct brw_reg src,
+                                         struct brw_reg surf_index)
+{
+   assert(devinfo->gen >= 7);
+   assert(surf_index.type == BRW_REGISTER_TYPE_UD &&
+          surf_index.file == BRW_IMMEDIATE_VALUE);
+
+   brw_SAMPLE(p,
+              dst,
+              inst->base_mrf,
+              src,
+              surf_index.dw1.ud,
+              0,
+              GEN5_SAMPLER_MESSAGE_SAMPLE_RESINFO,
+              1, /* response length */
+              inst->mlen,
+              inst->header_size > 0,
+              BRW_SAMPLER_SIMD_MODE_SIMD4X2,
+              BRW_SAMPLER_RETURN_FORMAT_SINT32);
+
+   brw_mark_surface_used(&prog_data->base, surf_index.dw1.ud);
+}
+
+void
 vec4_generator::generate_pull_constant_load_gen7(vec4_instruction *inst,
                                                  struct brw_reg dst,
                                                  struct brw_reg surf_index,
@@ -1409,6 +1435,11 @@ vec4_generator::generate_code(const cfg_t *cfg)
          generate_set_simd4x2_header_gen9(inst, dst);
          break;
 
+
+      case VS_OPCODE_GET_BUFFER_SIZE:
+         generate_get_buffer_size(inst, dst, src[0], src[1]);
+         break;
+
       case GS_OPCODE_URB_WRITE:
          generate_gs_urb_write(inst);
          break;