[Mesa-dev] [PATCH 2/4] glsl: rewrite clip/cull distance lowering pass
Dave Airlie
airlied at gmail.com
Fri May 20 03:47:29 UTC 2016
From: Dave Airlie <airlied at redhat.com>
The last version of this broke clipping, and I had to spend
sometime getting this working properly.
I had to introduce a third pass to count the clip/cull totals,
all due to one messy corner case. We have a piglit test
tes-input-gl_ClipDistance.shader_test
that doesn't actually output the clip distances, it just passes
them like a varying from TCS->TES, the older lowering pass worked
but to lower clip/cull we need to know the total number of clip+culls
used to defined the new variable correctly, and to offset culls
properly.
This adds an extra pass that works out the sizes for clip/cull,
then lowers gl_ClipDistance then gl_CullDistance into the new
gl_ClipDistanceMESA.
The pass checks using the fixed array sizes code if they array
has been referenced, or is actually never used, and ignores
it in the latter case.
Signed-off-by: Dave Airlie <airlied at redhat.com>
---
src/compiler/glsl/ir_optimization.h | 2 +-
src/compiler/glsl/linker.cpp | 2 +-
src/compiler/glsl/lower_distance.cpp | 220 ++++++++++++++++++++++++++---------
3 files changed, 164 insertions(+), 60 deletions(-)
diff --git a/src/compiler/glsl/ir_optimization.h b/src/compiler/glsl/ir_optimization.h
index 5fc2740..71b10e4 100644
--- a/src/compiler/glsl/ir_optimization.h
+++ b/src/compiler/glsl/ir_optimization.h
@@ -119,7 +119,7 @@ bool lower_variable_index_to_cond_assign(gl_shader_stage stage,
bool lower_temp, bool lower_uniform);
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);
+bool lower_clip_cull_distance(struct gl_shader_program *prog, gl_shader *shader);
void lower_output_reads(unsigned stage, exec_list *instructions);
bool lower_packing_builtins(exec_list *instructions, int op_mask);
void lower_shared_reference(struct gl_shader *shader, unsigned *shared_size);
diff --git a/src/compiler/glsl/linker.cpp b/src/compiler/glsl/linker.cpp
index b856631..4b5b32c 100644
--- a/src/compiler/glsl/linker.cpp
+++ b/src/compiler/glsl/linker.cpp
@@ -4639,7 +4639,7 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
goto done;
if (ctx->Const.ShaderCompilerOptions[i].LowerCombinedClipCullDistance) {
- lower_clip_distance(prog->_LinkedShaders[i]);
+ lower_clip_cull_distance(prog, prog->_LinkedShaders[i]);
}
if (ctx->Const.LowerTessLevel) {
diff --git a/src/compiler/glsl/lower_distance.cpp b/src/compiler/glsl/lower_distance.cpp
index 301afe4..f21a1be 100644
--- a/src/compiler/glsl/lower_distance.cpp
+++ b/src/compiler/glsl/lower_distance.cpp
@@ -45,19 +45,41 @@
* LowerCombinedClipCullDistance flag in gl_shader_compiler_options to true.
*/
+#include "main/macros.h"
#include "glsl_symbol_table.h"
#include "ir_rvalue_visitor.h"
#include "ir.h"
#include "program/prog_instruction.h" /* For WRITEMASK_* */
+#define GLSL_CLIP_VAR_NAME "gl_ClipDistanceMESA"
+
namespace {
class lower_distance_visitor : public ir_rvalue_visitor {
public:
- explicit lower_distance_visitor(gl_shader_stage shader_stage)
+ explicit lower_distance_visitor(gl_shader_stage shader_stage,
+ const char *in_name, int total_size,
+ int offset)
: progress(false), old_distance_out_var(NULL),
old_distance_in_var(NULL), new_distance_out_var(NULL),
- new_distance_in_var(NULL), shader_stage(shader_stage)
+ new_distance_in_var(NULL), shader_stage(shader_stage),
+ in_name(in_name), total_size(total_size), offset(offset)
+ {
+ }
+
+ explicit lower_distance_visitor(gl_shader_stage shader_stage,
+ const char *in_name,
+ const lower_distance_visitor *orig,
+ int offset)
+ : progress(false),
+ old_distance_out_var(NULL),
+ old_distance_in_var(NULL),
+ new_distance_out_var(orig->new_distance_out_var),
+ new_distance_in_var(orig->new_distance_in_var),
+ shader_stage(shader_stage),
+ in_name(in_name),
+ total_size(orig->total_size),
+ offset(offset)
{
}
@@ -100,12 +122,15 @@ public:
* Type of shader we are compiling (e.g. MESA_SHADER_VERTEX)
*/
const gl_shader_stage shader_stage;
+ const char *in_name;
+ int total_size;
+ int offset;
};
} /* anonymous namespace */
/**
- * Replace any declaration of gl_ClipDistance as an array of floats with a
+ * Replace any declaration of 'in_name' as an array of floats with a
* declaration of gl_ClipDistanceMESA as an array of vec4's.
*/
ir_visitor_status
@@ -114,7 +139,7 @@ lower_distance_visitor::visit(ir_variable *ir)
ir_variable **old_var;
ir_variable **new_var;
- if (!ir->name || strcmp(ir->name, "gl_ClipDistance") != 0)
+ if (!ir->name || strcmp(ir->name, in_name) != 0)
return visit_continue;
assert (ir->type->is_array());
@@ -134,56 +159,53 @@ lower_distance_visitor::visit(ir_variable *ir)
this->progress = true;
- if (!ir->type->fields.array->is_array()) {
- /* gl_ClipDistance (used for vertex, tessellation evaluation and
- * geometry output, and fragment input).
- */
- assert((ir->data.mode == ir_var_shader_in &&
- this->shader_stage == MESA_SHADER_FRAGMENT) ||
- (ir->data.mode == ir_var_shader_out &&
- (this->shader_stage == MESA_SHADER_VERTEX ||
- this->shader_stage == MESA_SHADER_TESS_EVAL ||
- this->shader_stage == MESA_SHADER_GEOMETRY)));
+ *old_var = ir;
- *old_var = ir;
- assert (ir->type->fields.array == glsl_type::float_type);
- unsigned new_size = (ir->type->array_size() + 3) / 4;
+ if (!(*new_var)) {
+ unsigned new_size = (total_size + 3) / 4;
/* Clone the old var so that we inherit all of its properties */
*new_var = ir->clone(ralloc_parent(ir), NULL);
-
- /* And change the properties that we need to change */
- (*new_var)->name = ralloc_strdup(*new_var, "gl_ClipDistanceMESA");
- (*new_var)->type = glsl_type::get_array_instance(glsl_type::vec4_type,
- new_size);
- (*new_var)->data.max_array_access = ir->data.max_array_access / 4;
-
+ (*new_var)->name = ralloc_strdup(*new_var, GLSL_CLIP_VAR_NAME);
+
+ if (!ir->type->fields.array->is_array()) {
+ /* gl_ClipDistance (used for vertex, tessellation evaluation and
+ * geometry output, and fragment input).
+ */
+ assert((ir->data.mode == ir_var_shader_in &&
+ this->shader_stage == MESA_SHADER_FRAGMENT) ||
+ (ir->data.mode == ir_var_shader_out &&
+ (this->shader_stage == MESA_SHADER_VERTEX ||
+ this->shader_stage == MESA_SHADER_TESS_EVAL ||
+ this->shader_stage == MESA_SHADER_GEOMETRY)));
+
+ assert (ir->type->fields.array == glsl_type::float_type);
+
+ /* And change the properties that we need to change */
+ (*new_var)->type = glsl_type::get_array_instance(glsl_type::vec4_type,
+ new_size);
+ (*new_var)->data.max_array_access = ir->data.max_array_access / 4;
+ } else {
+ /* 2D gl_ClipDistance (used for tessellation control, tessellation
+ * evaluation and geometry input, and tessellation control output).
+ */
+ assert((ir->data.mode == ir_var_shader_in &&
+ (this->shader_stage == MESA_SHADER_GEOMETRY ||
+ this->shader_stage == MESA_SHADER_TESS_EVAL)) ||
+ this->shader_stage == MESA_SHADER_TESS_CTRL);
+
+ assert (ir->type->fields.array->fields.array == glsl_type::float_type);
+
+ /* And change the properties that we need to change */
+ (*new_var)->type = glsl_type::get_array_instance(
+ glsl_type::get_array_instance(glsl_type::vec4_type,
+ new_size),
+ ir->type->array_size());
+ (*new_var)->data.max_array_access = ir->data.max_array_access / 4;
+ }
ir->replace_with(*new_var);
} else {
- /* 2D gl_ClipDistance (used for tessellation control, tessellation
- * evaluation and geometry input, and tessellation control output).
- */
- assert((ir->data.mode == ir_var_shader_in &&
- (this->shader_stage == MESA_SHADER_GEOMETRY ||
- this->shader_stage == MESA_SHADER_TESS_EVAL)) ||
- this->shader_stage == MESA_SHADER_TESS_CTRL);
-
- *old_var = ir;
- assert (ir->type->fields.array->fields.array == glsl_type::float_type);
- unsigned new_size = (ir->type->fields.array->array_size() + 3) / 4;
-
- /* Clone the old var so that we inherit all of its properties */
- *new_var = ir->clone(ralloc_parent(ir), NULL);
-
- /* And change the properties that we need to change */
- (*new_var)->name = ralloc_strdup(*new_var, "gl_ClipDistanceMESA");
- (*new_var)->type = glsl_type::get_array_instance(
- glsl_type::get_array_instance(glsl_type::vec4_type,
- new_size),
- ir->type->array_size());
- (*new_var)->data.max_array_access = ir->data.max_array_access / 4;
-
- ir->replace_with(*new_var);
+ ir->remove();
}
return visit_continue;
@@ -219,7 +241,7 @@ lower_distance_visitor::create_indices(ir_rvalue *old_index,
* creating expressions to calculate the lowered indices. Just create
* constants.
*/
- int const_val = old_index_constant->get_int_component(0);
+ int const_val = old_index_constant->get_int_component(0) + offset;
array_index = new(ctx) ir_constant(const_val / 4);
swizzle_index = new(ctx) ir_constant(const_val % 4);
} else {
@@ -236,14 +258,16 @@ lower_distance_visitor::create_indices(ir_rvalue *old_index,
* shift because that's likely to be more efficient.
*/
array_index = new(ctx) ir_expression(
- ir_binop_rshift, new(ctx) ir_dereference_variable(old_index_var),
+ ir_binop_rshift,
+ new(ctx) ir_expression(ir_binop_add, new(ctx) ir_dereference_variable(old_index_var), new(ctx) ir_constant(offset)),
new(ctx) ir_constant(2));
/* Create the expression distance_index % 4. Do this as a bitwise
* AND because that's likely to be more efficient.
*/
swizzle_index = new(ctx) ir_expression(
- ir_binop_bit_and, new(ctx) ir_dereference_variable(old_index_var),
+ ir_binop_bit_and,
+ new(ctx) ir_expression(ir_binop_add, new(ctx) ir_dereference_variable(old_index_var), new(ctx) ir_constant(offset)),
new(ctx) ir_constant(3));
}
}
@@ -557,18 +581,98 @@ lower_distance_visitor::visit_leave(ir_call *ir)
return rvalue_visit(ir);
}
+namespace {
+class lower_distance_visitor_counter : public ir_rvalue_visitor {
+public:
+ explicit lower_distance_visitor_counter(void)
+ : in_clip_size(0), in_cull_size(0),
+ out_clip_size(0), out_cull_size(0)
+ {
+ }
+
+ virtual ir_visitor_status visit(ir_variable *);
+ virtual void handle_rvalue(ir_rvalue **rvalue);
+
+ int in_clip_size;
+ int in_cull_size;
+ int out_clip_size;
+ int out_cull_size;
+};
+
+}
+/**
+ * Count gl_ClipDistance and gl_CullDistance sizes.
+ */
+ir_visitor_status
+lower_distance_visitor_counter::visit(ir_variable *ir)
+{
+ int *clip_size, *cull_size;
+
+ if (!ir->name)
+ return visit_continue;
+
+ if (ir->data.mode == ir_var_shader_out) {
+ clip_size = &out_clip_size;
+ cull_size = &out_cull_size;
+ } else if (ir->data.mode == ir_var_shader_in) {
+ clip_size = &in_clip_size;
+ cull_size = &in_cull_size;
+ } else
+ return visit_continue;
+
+ if (ir->type->is_unsized_array())
+ return visit_continue;
+
+ if (*clip_size == 0) {
+ if (!strcmp(ir->name, "gl_ClipDistance")) {
+ if (!ir->type->fields.array->is_array())
+ *clip_size = ir->type->array_size();
+ else
+ *clip_size = ir->type->fields.array->array_size();
+ }
+ }
+
+ if (*cull_size == 0) {
+ if (!strcmp(ir->name, "gl_CullDistance")) {
+ if (!ir->type->fields.array->is_array())
+ *cull_size = ir->type->array_size();
+ else
+ *cull_size = ir->type->fields.array->array_size();
+ }
+ }
+ return visit_continue;
+}
+
+void
+lower_distance_visitor_counter::handle_rvalue(ir_rvalue **rv)
+{
+ return;
+}
bool
-lower_clip_distance(gl_shader *shader)
+lower_clip_cull_distance(struct gl_shader_program *prog, gl_shader *shader)
{
- lower_distance_visitor v(shader->Stage);
+ int clip_size, cull_size;
+
+ lower_distance_visitor_counter count;
+ visit_list_elements(&count, shader->ir);
+
+ clip_size = MAX2(count.in_clip_size, count.out_clip_size);
+ cull_size = MAX2(count.in_cull_size, count.out_cull_size);
+ if (clip_size == 0 && cull_size == 0)
+ return false;
+
+ lower_distance_visitor v(shader->Stage, "gl_ClipDistance", clip_size + cull_size, 0);
visit_list_elements(&v, shader->ir);
- if (v.new_distance_out_var)
- shader->symbols->add_variable(v.new_distance_out_var);
- if (v.new_distance_in_var)
- shader->symbols->add_variable(v.new_distance_in_var);
+ lower_distance_visitor v2(shader->Stage, "gl_CullDistance", &v, clip_size);
+ visit_list_elements(&v2, shader->ir);
+
+ if (v2.new_distance_out_var)
+ shader->symbols->add_variable(v2.new_distance_out_var);
+ if (v2.new_distance_in_var)
+ shader->symbols->add_variable(v2.new_distance_in_var);
- return v.progress;
+ return v2.progress;
}
--
2.5.5
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