[Mesa-dev] [PATCH 04/11] glsl: Extend lowering pass for gl_ClipDistance to support other arrays (v4)
Dave Airlie
airlied at gmail.com
Fri May 13 21:10:15 UTC 2016
From: Tobias Klausmann <tobias.johannes.klausmann at mni.thm.de>
This will come in handy when we want to lower gl_CullDistance into
gl_CullDistanceMESA.
[airlied: drop separate APIs for clip/cull - just use single API
to call both passes.]
v3: reexamine my sanity, this was pretty broken, the new code
creates one copy of gl_ClipDistanceMESA, as the clip distance
varying and lowers everything into that in two passes, one for clips
one for culls.
v4: rework using the passes in clip/cull sizes, instead of the
array sizes.
Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann at mni.thm.de>
Signed-off-by: Dave Airlie <airlied at redhat.com>
---
src/compiler/glsl/ir_optimization.h | 4 +-
src/compiler/glsl/linker.cpp | 4 +-
src/compiler/glsl/lower_distance.cpp | 248 ++++++++++++++++++++++-------------
3 files changed, 161 insertions(+), 95 deletions(-)
diff --git a/src/compiler/glsl/ir_optimization.h b/src/compiler/glsl/ir_optimization.h
index f9599a3..2a1b709 100644
--- a/src/compiler/glsl/ir_optimization.h
+++ b/src/compiler/glsl/ir_optimization.h
@@ -117,7 +117,9 @@ 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_combined_clip_cull_distance(gl_shader *shader,
+ uint8_t clipDistanceArraySize,
+ uint8_t cullDistanceArraySize);
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 2a520bc..a85072d 100644
--- a/src/compiler/glsl/linker.cpp
+++ b/src/compiler/glsl/linker.cpp
@@ -4561,7 +4561,9 @@ 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_combined_clip_cull_distance(prog->_LinkedShaders[i],
+ (uint8_t)prog->LastClipDistanceArraySize,
+ (uint8_t)prog->LastCullDistanceArraySize);
}
if (ctx->Const.LowerTessLevel) {
diff --git a/src/compiler/glsl/lower_distance.cpp b/src/compiler/glsl/lower_distance.cpp
index 301afe4..0316fb5 100644
--- a/src/compiler/glsl/lower_distance.cpp
+++ b/src/compiler/glsl/lower_distance.cpp
@@ -25,14 +25,17 @@
* \file lower_distance.cpp
*
* This pass accounts for the difference between the way
- * gl_ClipDistance is declared in standard GLSL (as an array of
- * floats), and the way it is frequently implemented in hardware (as
- * a pair of vec4s, with four clip distances packed into each).
+ * gl_ClipDistance or gl_CullDistance is declared in standard GLSL
+ * (as an array of floats), and the way it is frequently implemented
+ * in hardware (as a pair of vec4s, with four clip or cull distances
+ * packed into each).
*
- * The declaration of gl_ClipDistance is replaced with a declaration
- * of gl_ClipDistanceMESA, and any references to gl_ClipDistance are
- * translated to refer to gl_ClipDistanceMESA with the appropriate
- * swizzling of array indices. For instance:
+ * The declarations of gl_ClipDistance or gl_CullDistance are replaced
+ * with a single declaration of gl_ClipDistanceMESA.
+ * Any references to the original gl_ClipDistance or gl_CullDistance
+ * are translated to refer to gl_ClipDistanceMESA with the appropriate
+ * swizzling of array indices.
+ * For instance:
*
* gl_ClipDistance[i]
*
@@ -40,11 +43,12 @@
*
* gl_ClipDistanceMESA[i>>2][i&3]
*
- * Since some hardware may not internally represent gl_ClipDistance as a pair
- * of vec4's, this lowering pass is optional. To enable it, set the
- * LowerCombinedClipCullDistance flag in gl_shader_compiler_options to true.
+ * Since some hardware may not internally represent these arrays as a
+ * pair of vec4's, this lowering pass is optional. To enable it, set
+ * the LowerCombinedClipCullDistance flag in gl_shader_compiler_options to true.
*/
+#include <string>
#include "glsl_symbol_table.h"
#include "ir_rvalue_visitor.h"
#include "ir.h"
@@ -54,10 +58,16 @@ 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,
+ std::string in_name, ir_variable *out_var,
+ int num_clip_dist, int num_cull_dist,
+ bool is_cull, bool replace_var)
: 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), out_var(out_var),
+ num_clip_dist(num_clip_dist), num_cull_dist(num_cull_dist),
+ is_cull(is_cull), replace_var(replace_var)
{
}
@@ -76,7 +86,7 @@ public:
bool progress;
/**
- * Pointer to the declaration of gl_ClipDistance, if found.
+ * Pointer to the declaration of ou arrays, if found.
*
* Note:
*
@@ -91,7 +101,7 @@ public:
ir_variable *old_distance_in_var;
/**
- * Pointer to the newly-created gl_ClipDistanceMESA variable.
+ * Pointer to the newly-created variable.
*/
ir_variable *new_distance_out_var;
ir_variable *new_distance_in_var;
@@ -100,13 +110,26 @@ public:
* Type of shader we are compiling (e.g. MESA_SHADER_VERTEX)
*/
const gl_shader_stage shader_stage;
+
+ /**
+ * Identifier of the variables we manipulate
+ */
+
+ std::string in_name;
+
+ ir_variable *out_var;
+ uint8_t num_clip_dist;
+ uint8_t num_cull_dist;
+ bool is_cull;
+ bool replace_var;
};
} /* anonymous namespace */
+
/**
- * Replace any declaration of gl_ClipDistance as an array of floats with a
- * declaration of gl_ClipDistanceMESA as an array of vec4's.
+ * Replace any declaration of in_name as an array of floats with a
+ * declaration of out_name as an array of vec4's.
*/
ir_visitor_status
lower_distance_visitor::visit(ir_variable *ir)
@@ -114,7 +137,7 @@ 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 || in_name.compare(ir->name) != 0)
return visit_continue;
assert (ir->type->is_array());
@@ -135,8 +158,8 @@ 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).
+ /* gl_ClipDistance / gl_CullDistance (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) ||
@@ -147,21 +170,17 @@ lower_distance_visitor::visit(ir_variable *ir)
*old_var = ir;
assert (ir->type->fields.array == glsl_type::float_type);
- unsigned new_size = (ir->type->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::vec4_type,
- new_size);
- (*new_var)->data.max_array_access = ir->data.max_array_access / 4;
-
- ir->replace_with(*new_var);
+ *new_var = out_var;
+ if (replace_var == true) {
+ ir->replace_with(*new_var);
+ replace_var = false;
+ } else {
+ ir->remove();
+ }
} else {
- /* 2D gl_ClipDistance (used for tessellation control, tessellation
- * evaluation and geometry input, and tessellation control output).
+ /* 2D gl_ClipDistance / gl_CullDistance (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 ||
@@ -170,20 +189,13 @@ lower_distance_visitor::visit(ir_variable *ir)
*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);
+ *new_var = out_var;
+ if (replace_var == true) {
+ ir->replace_with(*new_var);
+ replace_var = false;
+ } else {
+ ir->remove();
+ }
}
return visit_continue;
@@ -191,10 +203,10 @@ lower_distance_visitor::visit(ir_variable *ir)
/**
- * Create the necessary GLSL rvalues to index into gl_ClipDistanceMESA based
+ * Create the necessary GLSL rvalues to index into out_name based
* on the rvalue previously used to index into gl_ClipDistance.
*
- * \param array_index Selects one of the vec4's in gl_ClipDistanceMESA
+ * \param array_index Selects one of the vec4's in out_name
* \param swizzle_index Selects a component within the vec4 selected by
* array_index.
*/
@@ -215,13 +227,14 @@ lower_distance_visitor::create_indices(ir_rvalue *old_index,
ir_constant *old_index_constant = old_index->constant_expression_value();
if (old_index_constant) {
- /* gl_ClipDistance is being accessed via a constant index. Don't bother
- * creating expressions to calculate the lowered indices. Just create
- * constants.
+ /* gl_ClipDistance / gl_CullDistance is being accessed via a constant
+ * index. Don't bother creating expressions to calculate the lowered
+ * indices. Just create constants.
*/
int const_val = old_index_constant->get_int_component(0);
- array_index = new(ctx) ir_constant(const_val / 4);
- swizzle_index = new(ctx) ir_constant(const_val % 4);
+ uint8_t offset = is_cull ? num_clip_dist : 0;
+ array_index = new(ctx) ir_constant((const_val + offset) / 4);
+ swizzle_index = new(ctx) ir_constant((const_val + offset) % 4);
} else {
/* Create a variable to hold the value of old_index (so that we
* don't compute it twice).
@@ -232,15 +245,15 @@ lower_distance_visitor::create_indices(ir_rvalue *old_index,
this->base_ir->insert_before(new(ctx) ir_assignment(
new(ctx) ir_dereference_variable(old_index_var), old_index));
- /* Create the expression distance_index / 4. Do this as a bit
- * shift because that's likely to be more efficient.
+ /* Create the expression distance_index / 4. Do this as a bit 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),
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.
+ /* 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),
@@ -260,9 +273,9 @@ lower_distance_visitor::create_indices(ir_rvalue *old_index,
bool
lower_distance_visitor::is_distance_vec8(ir_rvalue *ir)
{
- /* Note that geometry shaders contain gl_ClipDistance both as an input
- * (which is a 2D array) and an output (which is a 1D array), so it's
- * possible for both this->old_distance_out_var and
+ /* Note that geometry shaders contain in_name
+ * both as an input (which is a 2D array) and an output (which is a 1D
+ * array), so it's possible for both this->old_distance_out_var and
* this->old_distance_in_var to be non-NULL in the same shader.
*/
@@ -340,9 +353,9 @@ lower_distance_visitor::handle_rvalue(ir_rvalue **rv)
if (array_deref == NULL)
return;
- /* Replace any expression that indexes one of the floats in gl_ClipDistance
- * with an expression that indexes into one of the vec4's in
- * gl_ClipDistanceMESA and accesses the appropriate component.
+ /* Replace any expression that indexes one of the floats in in_name
+ * or in_name with an expression that indexes into one of the vec4's
+ * in out_name and accesses the appropriate component.
*/
ir_rvalue *lowered_vec8 =
this->lower_distance_vec8(array_deref->array);
@@ -392,12 +405,12 @@ lower_distance_visitor::fix_lhs(ir_assignment *ir)
}
/**
- * Replace any assignment having the 1D gl_ClipDistance (undereferenced) as
+ * Replace any assignment having the 1D in_name (undereferenced) as
* its LHS or RHS with a sequence of assignments, one for each component of
* the array. Each of these assignments is lowered to refer to
- * gl_ClipDistanceMESA as appropriate.
+ * out_name as appropriate.
*
- * We need to do a similar replacement for 2D gl_ClipDistance, however since
+ * We need to do a similar replacement for 2D in_name, however since
* it's an input, the only case we need to address is where a 1D slice of it
* is the entire RHS of an assignment, e.g.:
*
@@ -413,9 +426,9 @@ lower_distance_visitor::visit_leave(ir_assignment *ir)
if (this->is_distance_vec8(ir->lhs) ||
this->is_distance_vec8(ir->rhs)) {
- /* LHS or RHS of the assignment is the entire 1D gl_ClipDistance array
- * (or a 1D slice of a 2D gl_ClipDistance input array). Since we are
- * reshaping gl_ClipDistance from an array of floats to an array of
+ /* LHS or RHS of the assignment is the entire 1D in_name array
+ * (or a 1D slice of a 2D in_name input array). Since we are
+ * reshaping in_name from an array of floats to an array of
* vec4's, this isn't going to work as a bulk assignment anymore, so
* unroll it to element-by-element assignments and lower each of them.
*
@@ -484,13 +497,13 @@ lower_distance_visitor::visit_new_assignment(ir_assignment *ir)
/**
- * If a 1D gl_ClipDistance variable appears as an argument in an ir_call
+ * If a 1D in_name variable appears as an argument in an ir_call
* expression, replace it with a temporary variable, and make sure the ir_call
* is preceded and/or followed by assignments that copy the contents of the
- * temporary variable to and/or from gl_ClipDistance. Each of these
- * assignments is then lowered to refer to gl_ClipDistanceMESA.
+ * temporary variable to and/or from in_name. Each of these
+ * assignments is then lowered to refer to out_name.
*
- * We need to do a similar replacement for 2D gl_ClipDistance, however since
+ * We need to do a similar replacement for 2D in_name, however since
* it's an input, the only case we need to address is where a 1D slice of it
* is passed as an "in" parameter to an ir_call, e.g.:
*
@@ -514,40 +527,40 @@ lower_distance_visitor::visit_leave(ir_call *ir)
actual_param_node = actual_param_node->next;
if (this->is_distance_vec8(actual_param)) {
- /* User is trying to pass the whole 1D gl_ClipDistance array (or a 1D
- * slice of a 2D gl_ClipDistance array) to a function call. Since we
- * are reshaping gl_ClipDistance from an array of floats to an array
+ /* User is trying to pass the whole 1D in_name array (or a 1D
+ * slice of a 2D in_name array) to a function call. Since we
+ * are reshaping in_name from an array of floats to an array
* of vec4's, this isn't going to work anymore, so use a temporary
* array instead.
*/
- ir_variable *temp_clip_distance = new(ctx) ir_variable(
- actual_param->type, "temp_clip_distance", ir_var_temporary);
- this->base_ir->insert_before(temp_clip_distance);
+ ir_variable *temp_distance = new(ctx) ir_variable(
+ actual_param->type, "temp_distance", ir_var_temporary);
+ this->base_ir->insert_before(temp_distance);
actual_param->replace_with(
- new(ctx) ir_dereference_variable(temp_clip_distance));
+ new(ctx) ir_dereference_variable(temp_distance));
if (formal_param->data.mode == ir_var_function_in
|| formal_param->data.mode == ir_var_function_inout) {
- /* Copy from gl_ClipDistance to the temporary before the call.
+ /* Copy from in_name to the temporary before the call.
* Since we are going to insert this copy before the current
* instruction, we need to visit it afterwards to make sure it
* gets lowered.
*/
ir_assignment *new_assignment = new(ctx) ir_assignment(
- new(ctx) ir_dereference_variable(temp_clip_distance),
+ new(ctx) ir_dereference_variable(temp_distance),
actual_param->clone(ctx, NULL));
this->base_ir->insert_before(new_assignment);
this->visit_new_assignment(new_assignment);
}
if (formal_param->data.mode == ir_var_function_out
|| formal_param->data.mode == ir_var_function_inout) {
- /* Copy from the temporary to gl_ClipDistance after the call.
+ /* Copy from the temporary to in_name after the call.
* Since visit_list_elements() has already decided which
* instruction it's going to visit next, we need to visit
* afterwards to make sure it gets lowered.
*/
ir_assignment *new_assignment = new(ctx) ir_assignment(
actual_param->clone(ctx, NULL),
- new(ctx) ir_dereference_variable(temp_clip_distance));
+ new(ctx) ir_dereference_variable(temp_distance));
this->base_ir->insert_after(new_assignment);
this->visit_new_assignment(new_assignment);
}
@@ -557,18 +570,67 @@ lower_distance_visitor::visit_leave(ir_call *ir)
return rvalue_visit(ir);
}
+static ir_variable *
+create_clip_distance_mesa(ir_variable *base, int new_size)
+{
+ ir_variable *new_var;
+
+ if (!base->type->fields.array->is_array()) {
+ new_var = base->clone(ralloc_parent(base), NULL);
+ 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 = base->data.max_array_access / 4;
+ } else {
+ /* Clone the old var so that we inherit all of its properties */
+ new_var = base->clone(ralloc_parent(base), 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),
+ base->type->array_size());
+ new_var->data.max_array_access = base->data.max_array_access / 4;
+ }
+ return new_var;
+}
bool
-lower_clip_distance(gl_shader *shader)
+lower_combined_clip_cull_distance(gl_shader *shader,
+ uint8_t ClipDistanceArraySize,
+ uint8_t CullDistanceArraySize)
{
- lower_distance_visitor v(shader->Stage);
+ ir_variable *clipdist = shader->symbols->get_variable("gl_ClipDistance");
+ ir_variable *culldist = shader->symbols->get_variable("gl_CullDistance");
+ ir_variable *new_var;
+ unsigned new_size = ((ClipDistanceArraySize + CullDistanceArraySize) + 3) / 4;
+ bool progress = false;
+ bool replace_var = true;
+
+ if (ClipDistanceArraySize == 0 && CullDistanceArraySize == 0)
+ return false;
+
+ new_var = create_clip_distance_mesa(clipdist ? clipdist : culldist, new_size);
- visit_list_elements(&v, shader->ir);
+ if (ClipDistanceArraySize) {
+ lower_distance_visitor v(shader->Stage, "gl_ClipDistance",
+ new_var, ClipDistanceArraySize, CullDistanceArraySize, false, replace_var);
+
+ visit_list_elements(&v, shader->ir);
+ replace_var = v.replace_var;
+ progress = v.progress;
+ }
+
+ if (CullDistanceArraySize) {
+ lower_distance_visitor v2(shader->Stage, "gl_CullDistance",
+ new_var, ClipDistanceArraySize, CullDistanceArraySize, true, replace_var);
+
+ visit_list_elements(&v2, shader->ir);
+ progress |= v2.progress;
+ }
- 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);
+ shader->symbols->add_variable(new_var);
- return v.progress;
+ validate_ir_tree(shader->ir);
+ return progress;
}
--
2.5.5
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