[Mesa-dev] [PATCH 10/13] i965: Automatically create a passthrough TCS when needed.
Kenneth Graunke
kenneth at whitecape.org
Tue Dec 22 02:20:55 PST 2015
Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
src/mesa/drivers/dri/i965/brw_tcs.c | 62 ++++++++++++++++++++++++++----
src/mesa/drivers/dri/i965/brw_vec4_tcs.cpp | 57 +++++++++++++++++++++++++--
src/mesa/drivers/dri/i965/brw_vec4_tcs.h | 6 ++-
3 files changed, 113 insertions(+), 12 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/brw_tcs.c b/src/mesa/drivers/dri/i965/brw_tcs.c
index 1da87ee..ecb6fd0 100644
--- a/src/mesa/drivers/dri/i965/brw_tcs.c
+++ b/src/mesa/drivers/dri/i965/brw_tcs.c
@@ -82,13 +82,31 @@ brw_codegen_tcs_prog(struct brw_context *brw,
struct brw_tess_ctrl_program *tcp,
struct brw_tcs_prog_key *key)
{
+ struct gl_context *ctx = &brw->ctx;
const struct brw_compiler *compiler = brw->intelScreen->compiler;
struct brw_stage_state *stage_state = &brw->tcs.base;
- nir_shader *nir = tcp->program.Base.nir;
+ nir_shader *nir;
struct brw_tcs_prog_data prog_data;
bool start_busy = false;
double start_time = 0;
+ if (tcp) {
+ nir = tcp->program.Base.nir;
+ } else {
+ /* Create a dummy nir_shader. We won't actually use NIR code to
+ * generate assembly (it's easier to generate assembly directly),
+ * but the whole compiler assumes one of these exists.
+ */
+ const nir_shader_compiler_options *options =
+ ctx->Const.ShaderCompilerOptions[MESA_SHADER_TESS_CTRL].NirOptions;
+ nir = nir_shader_create(NULL, MESA_SHADER_TESS_CTRL, options);
+ nir->num_uniforms = 2; /* both halves of the patch header */
+ nir->info.outputs_written = key->outputs_written;
+ nir->info.inputs_read = key->outputs_written;
+ nir->info.tcs.vertices_out = key->input_vertices;
+ nir->info.name = ralloc_strdup(nir, "passthrough");
+ }
+
memset(&prog_data, 0, sizeof(prog_data));
/* Allocate the references to the uniforms that will end up in the
@@ -99,7 +117,8 @@ brw_codegen_tcs_prog(struct brw_context *brw,
* padding around uniform values below vec4 size, so the worst case is that
* every uniform is a float which gets padded to the size of a vec4.
*/
- struct gl_shader *tcs = shader_prog->_LinkedShaders[MESA_SHADER_TESS_CTRL];
+ struct gl_shader *tcs = shader_prog ?
+ shader_prog->_LinkedShaders[MESA_SHADER_TESS_CTRL] : NULL;
int param_count = nir->num_uniforms;
if (!compiler->scalar_stage[MESA_SHADER_TESS_CTRL])
param_count *= 4;
@@ -108,15 +127,38 @@ brw_codegen_tcs_prog(struct brw_context *brw,
rzalloc_array(NULL, const gl_constant_value *, param_count);
prog_data.base.base.pull_param =
rzalloc_array(NULL, const gl_constant_value *, param_count);
- prog_data.base.base.image_param =
- rzalloc_array(NULL, struct brw_image_param, tcs->NumImages);
prog_data.base.base.nr_params = param_count;
- prog_data.base.base.nr_image_params = tcs->NumImages;
- brw_nir_setup_glsl_uniforms(nir, shader_prog, &tcp->program.Base,
- &prog_data.base.base, false);
+ if (tcs) {
+ prog_data.base.base.image_param =
+ rzalloc_array(NULL, struct brw_image_param, tcs->NumImages);
+ prog_data.base.base.nr_image_params = tcs->NumImages;
+
+ brw_nir_setup_glsl_uniforms(nir, shader_prog, &tcp->program.Base,
+ &prog_data.base.base, false);
+ } else {
+ /* Upload the Patch URB Header as the first two uniforms.
+ * Do the annoying scrambling so the shader doesn't have to.
+ */
+ const float **param = (const float **) prog_data.base.base.param;
+ static float zero = 0.0f;
+ for (int i = 0; i < 4; i++) {
+ param[7 - i] = &ctx->TessCtrlProgram.patch_default_outer_level[i];
+ }
+
+ if (key->tes_primitive_mode == GL_QUADS) {
+ param[3] = &ctx->TessCtrlProgram.patch_default_inner_level[0];
+ param[2] = &ctx->TessCtrlProgram.patch_default_inner_level[1];
+ param[1] = &zero;
+ param[0] = &zero;
+ } else if (key->tes_primitive_mode == GL_TRIANGLES) {
+ param[4] = &ctx->TessCtrlProgram.patch_default_inner_level[0];
+ for (int i = 0; i < 4; i++)
+ param[i] = &zero;
+ }
+ }
- if (unlikely(INTEL_DEBUG & DEBUG_TCS))
+ if (unlikely(INTEL_DEBUG & DEBUG_TCS) && tcs)
brw_dump_ir("tessellation control", shader_prog, tcs, NULL);
int st_index = -1;
@@ -138,6 +180,8 @@ brw_codegen_tcs_prog(struct brw_context *brw,
if (shader_prog) {
shader_prog->LinkStatus = false;
ralloc_strcat(&shader_prog->InfoLog, error_str);
+ } else {
+ ralloc_free(nir);
}
_mesa_problem(NULL, "Failed to compile tessellation control shader: "
@@ -172,6 +216,8 @@ brw_codegen_tcs_prog(struct brw_context *brw,
&prog_data, sizeof(prog_data),
&stage_state->prog_offset, &brw->tcs.prog_data);
ralloc_free(mem_ctx);
+ if (!tcs)
+ ralloc_free(nir);
return true;
}
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_tcs.cpp b/src/mesa/drivers/dri/i965/brw_vec4_tcs.cpp
index bd98559..4bcf99e 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_tcs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_tcs.cpp
@@ -38,15 +38,66 @@ vec4_tcs_visitor::vec4_tcs_visitor(const struct brw_compiler *compiler,
struct brw_tcs_prog_data *prog_data,
const nir_shader *nir,
void *mem_ctx,
- int shader_time_index)
+ int shader_time_index,
+ const struct brw_vue_map *input_vue_map)
: vec4_visitor(compiler, log_data, &key->tex, &prog_data->base,
nir, mem_ctx, false, shader_time_index),
- key(key)
+ input_vue_map(input_vue_map), key(key)
{
}
void
+vec4_tcs_visitor::emit_nir_code()
+{
+ if (key->program_string_id != 0) {
+ /* We have a real application-supplied TCS, emit real code. */
+ vec4_visitor::emit_nir_code();
+ } else {
+ /* There is no TCS; automatically generate a passthrough shader
+ * that writes the API-specified default tessellation levels and
+ * copies VS outputs to TES inputs.
+ */
+ uniforms = 2;
+ uniform_size[0] = 1;
+ uniform_size[1] = 1;
+
+ uint64_t varyings = key->outputs_written;
+
+ src_reg vertex_offset(this, glsl_type::uint_type);
+ emit(MUL(dst_reg(vertex_offset), invocation_id,
+ brw_imm_ud(prog_data->vue_map.num_per_vertex_slots)));
+
+ while (varyings != 0) {
+ const int varying = ffsll(varyings) - 1;
+
+ unsigned in_offset = input_vue_map->varying_to_slot[varying];
+ unsigned out_offset = prog_data->vue_map.varying_to_slot[varying];
+ assert(out_offset >= 2);
+
+ dst_reg val(this, glsl_type::vec4_type);
+ emit_input_urb_read(val, invocation_id, in_offset, src_reg());
+ emit_urb_write(src_reg(val), WRITEMASK_XYZW, out_offset,
+ vertex_offset);
+
+ varyings &= ~BITFIELD64_BIT(varying);
+ }
+
+ /* Only write the tessellation factors from invocation 0.
+ * There's no point in making other threads do redundant work.
+ */
+ emit(CMP(dst_null_d(), invocation_id, brw_imm_ud(0),
+ BRW_CONDITIONAL_EQ));
+ emit(IF(BRW_PREDICATE_NORMAL));
+ emit_urb_write(src_reg(UNIFORM, 0, glsl_type::vec4_type),
+ WRITEMASK_XYZW, 0, src_reg());
+ emit_urb_write(src_reg(UNIFORM, 1, glsl_type::vec4_type),
+ WRITEMASK_XYZW, 1, src_reg());
+ emit(BRW_OPCODE_ENDIF);
+ }
+}
+
+void
vec4_tcs_visitor::nir_setup_system_value_intrinsic(nir_intrinsic_instr *instr)
{
}
@@ -478,7 +529,7 @@ brw_compile_tcs(const struct brw_compiler *compiler,
}
vec4_tcs_visitor v(compiler, log_data, key, prog_data,
- nir, mem_ctx, shader_time_index);
+ nir, mem_ctx, shader_time_index, &input_vue_map);
if (!v.run()) {
if (error_str)
*error_str = ralloc_strdup(mem_ctx, v.fail_msg);
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_tcs.h b/src/mesa/drivers/dri/i965/brw_vec4_tcs.h
index 2bf4885..2c6801b 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_tcs.h
+++ b/src/mesa/drivers/dri/i965/brw_vec4_tcs.h
@@ -45,9 +45,11 @@ public:
struct brw_tcs_prog_data *prog_data,
const nir_shader *nir,
void *mem_ctx,
- int shader_time_index);
+ int shader_time_index,
+ const struct brw_vue_map *input_vue_map);
protected:
+ virtual void emit_nir_code();
virtual dst_reg *make_reg_for_system_value(int location,
const glsl_type *type);
virtual void nir_setup_system_value_intrinsic(nir_intrinsic_instr *instr);
@@ -74,6 +76,8 @@ protected:
virtual void emit_urb_write_header(int mrf) {}
virtual vec4_instruction *emit_urb_write_opcode(bool complete) { return NULL; }
+ const struct brw_vue_map *input_vue_map;
+
const struct brw_tcs_prog_key *key;
src_reg invocation_id;
};
--
2.6.4
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