glsl: pass shader stage to lower_output_reads and handle tess control

Tessellation control outputs can be read in directly without first
having been written. Accessing these will require some special logic
anyways, so just let them through.

V2: Never lower tess control output reads, whether patch or not -- both
can be read back by other threads.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

diff --git a/src/glsl/ir_optimization.h b/src/glsl/ir_optimization.h
index a174c9683a16955b5ac464703343d84367cb76d1..766b723df0b94db0ea639bbc63619372a75af477 100644 (file)
--- a/src/glsl/ir_optimization.h
+++ b/src/glsl/ir_optimization.h
@@ -120,7 +120,7 @@ bool lower_variable_index_to_cond_assign(gl_shader_stage stage,
 bool lower_quadop_vector(exec_list *instructions, bool dont_lower_swz);
 bool lower_const_arrays_to_uniforms(exec_list *instructions);
 bool lower_clip_distance(gl_shader *shader);
-void lower_output_reads(exec_list *instructions);
+void lower_output_reads(unsigned stage, exec_list *instructions);
 bool lower_packing_builtins(exec_list *instructions, int op_mask);
 void lower_ubo_reference(struct gl_shader *shader, exec_list *instructions);
 void lower_packed_varyings(void *mem_ctx,

diff --git a/src/glsl/lower_output_reads.cpp b/src/glsl/lower_output_reads.cpp
index 1ee815d5eceb35d21e32b9f392044b7453f15fa3..79488df2932da251db0baae0bbfcf8b2683da955 100644 (file)
--- a/src/glsl/lower_output_reads.cpp
+++ b/src/glsl/lower_output_reads.cpp
@@ -48,8 +48,10 @@ protected:
    hash_table *replacements;
 
    void *mem_ctx;
+
+   unsigned stage;
 public:
-   output_read_remover();
+   output_read_remover(unsigned stage);
    ~output_read_remover();
    virtual ir_visitor_status visit(class ir_dereference_variable *);
    virtual ir_visitor_status visit_leave(class ir_emit_vertex *);
@@ -75,8 +77,9 @@ hash_table_var_hash(const void *key)
    return hash_table_string_hash(var->name);
 }
 
-output_read_remover::output_read_remover()
+output_read_remover::output_read_remover(unsigned stage)
 {
+   this->stage = stage;
    mem_ctx = ralloc_context(NULL);
    replacements =
       hash_table_ctor(0, hash_table_var_hash, hash_table_pointer_compare);
@@ -93,6 +96,8 @@ output_read_remover::visit(ir_dereference_variable *ir)
 {
    if (ir->var->data.mode != ir_var_shader_out)
       return visit_continue;
+   if (stage == MESA_SHADER_TESS_CTRL)
+      return visit_continue;
 
    ir_variable *temp = (ir_variable *) hash_table_find(replacements, ir->var);
 
@@ -166,8 +171,8 @@ output_read_remover::visit_leave(ir_function_signature *sig)
 }
 
 void
-lower_output_reads(exec_list *instructions)
+lower_output_reads(unsigned stage, exec_list *instructions)
 {
-   output_read_remover v;
+   output_read_remover v(stage);
    visit_list_elements(&v, instructions);
 }

diff --git a/src/mesa/drivers/dri/i965/brw_shader.cpp b/src/mesa/drivers/dri/i965/brw_shader.cpp
index 379ff4a3a1aca54100962e83c1795238ef324891..9d60543c1674f76d401b168cd87021a2dcffeaca 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_shader.cpp
+++ b/src/mesa/drivers/dri/i965/brw_shader.cpp
@@ -316,7 +316,7 @@ process_glsl_ir(gl_shader_stage stage,
    } while (progress);
 
    if (options->NirOptions != NULL)
-      lower_output_reads(shader->ir);
+      lower_output_reads(stage, shader->ir);
 
    validate_ir_tree(shader->ir);
 

diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index b727c5e9c93f081ee086faf14f9e512df8110475..0ed16aeab8754a9ae1d4d1e0a2898cc45498892e 100644 (file)
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -5674,7 +5674,7 @@ get_mesa_program(struct gl_context *ctx,
                                                prog->Parameters);
 
    /* Remove reads from output registers. */
-   lower_output_reads(shader->ir);
+   lower_output_reads(shader->Stage, shader->ir);
 
    /* Emit intermediate IR for main(). */
    visit_exec_list(shader->ir, v);