[Mesa-dev] [PATCH 06/11] glsl: lower cull_distance into cull_distance_mesa
Tobias Klausmann
tobias.johannes.klausmann at mni.thm.de
Sun May 24 10:58:04 PDT 2015
From: Dave Airlie <airlied at redhat.com>
Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann at mni.thm.de>
---
src/glsl/Makefile.sources | 1 +
src/glsl/ir_optimization.h | 1 +
src/glsl/link_varyings.cpp | 15 +-
src/glsl/link_varyings.h | 3 +-
src/glsl/linker.cpp | 1 +
src/glsl/lower_cull_distance.cpp | 549 +++++++++++++++++++++++++++++++++++++++
6 files changed, 565 insertions(+), 5 deletions(-)
create mode 100644 src/glsl/lower_cull_distance.cpp
diff --git a/src/glsl/Makefile.sources b/src/glsl/Makefile.sources
index d784a81..502b6ca 100644
--- a/src/glsl/Makefile.sources
+++ b/src/glsl/Makefile.sources
@@ -143,6 +143,7 @@ LIBGLSL_FILES = \
loop_unroll.cpp \
lower_clip_distance.cpp \
lower_const_arrays_to_uniforms.cpp \
+ lower_cull_distance.cpp \
lower_discard.cpp \
lower_discard_flow.cpp \
lower_if_to_cond_assign.cpp \
diff --git a/src/glsl/ir_optimization.h b/src/glsl/ir_optimization.h
index e6939f3..1220df6 100644
--- a/src/glsl/ir_optimization.h
+++ b/src/glsl/ir_optimization.h
@@ -119,6 +119,7 @@ bool lower_variable_index_to_cond_assign(exec_list *instructions,
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_cull_distance(gl_shader *shader);
void lower_output_reads(exec_list *instructions);
bool lower_packing_builtins(exec_list *instructions, int op_mask);
void lower_ubo_reference(struct gl_shader *shader, exec_list *instructions);
diff --git a/src/glsl/link_varyings.cpp b/src/glsl/link_varyings.cpp
index 7b2d4bd..46f84c6 100644
--- a/src/glsl/link_varyings.cpp
+++ b/src/glsl/link_varyings.cpp
@@ -301,6 +301,7 @@ tfeedback_decl::init(struct gl_context *ctx, const void *mem_ctx,
this->location = -1;
this->orig_name = input;
this->is_clip_distance_mesa = false;
+ this->is_cull_distance_mesa = false;
this->skip_components = 0;
this->next_buffer_separator = false;
this->matched_candidate = NULL;
@@ -351,6 +352,10 @@ tfeedback_decl::init(struct gl_context *ctx, const void *mem_ctx,
strcmp(this->var_name, "gl_ClipDistance") == 0) {
this->is_clip_distance_mesa = true;
}
+ if (ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].LowerClipDistance &&
+ strcmp(this->var_name, "gl_CullDistance") == 0) {
+ this->is_cull_distance_mesa = true;
+ }
}
@@ -397,7 +402,8 @@ tfeedback_decl::assign_location(struct gl_context *ctx,
this->matched_candidate->type->fields.array->matrix_columns;
const unsigned vector_elements =
this->matched_candidate->type->fields.array->vector_elements;
- unsigned actual_array_size = this->is_clip_distance_mesa ?
+ unsigned actual_array_size =
+ (this->is_clip_distance_mesa || this->is_cull_distance_mesa) ?
prog->LastClipDistanceArraySize :
this->matched_candidate->type->array_size();
@@ -410,7 +416,8 @@ tfeedback_decl::assign_location(struct gl_context *ctx,
actual_array_size);
return false;
}
- unsigned array_elem_size = this->is_clip_distance_mesa ?
+ unsigned array_elem_size =
+ (this->is_clip_distance_mesa || this->is_cull_distance_mesa) ?
1 : vector_elements * matrix_cols;
fine_location += array_elem_size * this->array_subscript;
this->size = 1;
@@ -419,7 +426,7 @@ tfeedback_decl::assign_location(struct gl_context *ctx,
}
this->vector_elements = vector_elements;
this->matrix_columns = matrix_cols;
- if (this->is_clip_distance_mesa)
+ if (this->is_clip_distance_mesa || this->is_cull_distance_mesa)
this->type = GL_FLOAT;
else
this->type = this->matched_candidate->type->fields.array->gl_type;
@@ -542,7 +549,7 @@ const tfeedback_candidate *
tfeedback_decl::find_candidate(gl_shader_program *prog,
hash_table *tfeedback_candidates)
{
- const char *name = this->is_clip_distance_mesa
+ const char *name = this->is_cull_distance_mesa ? "gl_CullDistanceMESA" : this->is_clip_distance_mesa
? "gl_ClipDistanceMESA" : this->var_name;
this->matched_candidate = (const tfeedback_candidate *)
hash_table_find(tfeedback_candidates, name);
diff --git a/src/glsl/link_varyings.h b/src/glsl/link_varyings.h
index afc16a8..842ab7c 100644
--- a/src/glsl/link_varyings.h
+++ b/src/glsl/link_varyings.h
@@ -128,7 +128,7 @@ public:
*/
unsigned num_components() const
{
- if (this->is_clip_distance_mesa)
+ if (this->is_clip_distance_mesa || this->is_cull_distance_mesa)
return this->size;
else
return this->vector_elements * this->matrix_columns * this->size;
@@ -165,6 +165,7 @@ private:
* gl_ClipDistance to gl_ClipDistanceMESA.
*/
bool is_clip_distance_mesa;
+ bool is_cull_distance_mesa;
/**
* The vertex shader output location that the linker assigned for this
diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index 8eace14..e616520 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -2938,6 +2938,7 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
if (ctx->Const.ShaderCompilerOptions[i].LowerClipDistance) {
lower_clip_distance(prog->_LinkedShaders[i]);
+ lower_cull_distance(prog->_LinkedShaders[i]);
}
while (do_common_optimization(prog->_LinkedShaders[i]->ir, true, false,
diff --git a/src/glsl/lower_cull_distance.cpp b/src/glsl/lower_cull_distance.cpp
new file mode 100644
index 0000000..d3b9592
--- /dev/null
+++ b/src/glsl/lower_cull_distance.cpp
@@ -0,0 +1,549 @@
+/*
+ * Copyright © 2011 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * \file lower_cull_distance.cpp
+ *
+ * This pass accounts for the difference between the way
+ * 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 cull distances packed into each).
+ *
+ * The declaration of gl_CullDistance is replaced with a declaration
+ * of gl_CullDistanceMESA, and any references to gl_CullDistance are
+ * translated to refer to gl_CullDistanceMESA with the appropriate
+ * swizzling of array indices. For instance:
+ *
+ * gl_CullDistance[i]
+ *
+ * is translated into:
+ *
+ * gl_CullDistanceMESA[i>>2][i&3]
+ *
+ * Since some hardware may not internally represent gl_CullDistance as a pair
+ * of vec4's, this lowering pass is optional. To enable it, set the
+ * LowerCullDistance flag in gl_shader_compiler_options to true.
+ */
+
+#include "glsl_symbol_table.h"
+#include "ir_rvalue_visitor.h"
+#include "ir.h"
+#include "program/prog_instruction.h" /* For WRITEMASK_* */
+
+namespace {
+
+class lower_cull_distance_visitor : public ir_rvalue_visitor {
+public:
+ explicit lower_cull_distance_visitor(gl_shader_stage shader_stage)
+ : progress(false), old_cull_distance_1d_var(NULL),
+ old_cull_distance_2d_var(NULL), new_cull_distance_1d_var(NULL),
+ new_cull_distance_2d_var(NULL), shader_stage(shader_stage)
+ {
+ }
+
+ virtual ir_visitor_status visit(ir_variable *);
+ void create_indices(ir_rvalue*, ir_rvalue *&, ir_rvalue *&);
+ bool is_cull_distance_vec8(ir_rvalue *ir);
+ ir_rvalue *lower_cull_distance_vec8(ir_rvalue *ir);
+ virtual ir_visitor_status visit_leave(ir_assignment *);
+ void visit_new_assignment(ir_assignment *ir);
+ virtual ir_visitor_status visit_leave(ir_call *);
+
+ virtual void handle_rvalue(ir_rvalue **rvalue);
+
+ void fix_lhs(ir_assignment *);
+
+ bool progress;
+
+ /**
+ * Pointer to the declaration of gl_CullDistance, if found.
+ *
+ * Note:
+ *
+ * - the 2d_var is for geometry shader input only.
+ *
+ * - since gl_CullDistance is available in geometry shaders as both an
+ * input and an output, it's possible for both old_cull_distance_1d_var
+ * and old_cull_distance_2d_var to be non-null.
+ */
+ ir_variable *old_cull_distance_1d_var;
+ ir_variable *old_cull_distance_2d_var;
+
+ /**
+ * Pointer to the newly-created gl_CullDistanceMESA variable.
+ */
+ ir_variable *new_cull_distance_1d_var;
+ ir_variable *new_cull_distance_2d_var;
+
+ /**
+ * Type of shader we are compiling (e.g. MESA_SHADER_VERTEX)
+ */
+ const gl_shader_stage shader_stage;
+};
+
+} /* anonymous namespace */
+
+/**
+ * Replace any declaration of gl_CullDistance as an array of floats with a
+ * declaration of gl_CullDistanceMESA as an array of vec4's.
+ */
+ir_visitor_status
+lower_cull_distance_visitor::visit(ir_variable *ir)
+{
+ if (!ir->name || strcmp(ir->name, "gl_CullDistance") != 0)
+ return visit_continue;
+ assert (ir->type->is_array());
+
+ if (!ir->type->fields.array->is_array()) {
+ /* 1D gl_CullDistance (used for vertex and geometry output, and fragment
+ * input).
+ */
+ if (this->old_cull_distance_1d_var)
+ return visit_continue;
+
+ this->progress = true;
+ this->old_cull_distance_1d_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 */
+ this->new_cull_distance_1d_var = ir->clone(ralloc_parent(ir), NULL);
+
+ /* And change the properties that we need to change */
+ this->new_cull_distance_1d_var->name
+ = ralloc_strdup(this->new_cull_distance_1d_var,
+ "gl_CullDistanceMESA");
+ this->new_cull_distance_1d_var->type
+ = glsl_type::get_array_instance(glsl_type::vec4_type, new_size);
+ this->new_cull_distance_1d_var->data.max_array_access
+ = ir->data.max_array_access / 4;
+
+ ir->replace_with(this->new_cull_distance_1d_var);
+ } else {
+ /* 2D gl_CullDistance (used for geometry input). */
+ assert(ir->data.mode == ir_var_shader_in &&
+ this->shader_stage == MESA_SHADER_GEOMETRY);
+ if (this->old_cull_distance_2d_var)
+ return visit_continue;
+
+ this->progress = true;
+ this->old_cull_distance_2d_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 */
+ this->new_cull_distance_2d_var = ir->clone(ralloc_parent(ir), NULL);
+
+ /* And change the properties that we need to change */
+ this->new_cull_distance_2d_var->name
+ = ralloc_strdup(this->new_cull_distance_2d_var, "gl_CullDistanceMESA");
+ this->new_cull_distance_2d_var->type = glsl_type::get_array_instance(
+ glsl_type::get_array_instance(glsl_type::vec4_type,
+ new_size),
+ ir->type->array_size());
+ this->new_cull_distance_2d_var->data.max_array_access
+ = ir->data.max_array_access / 4;
+
+ ir->replace_with(this->new_cull_distance_2d_var);
+ }
+ return visit_continue;
+}
+
+
+/**
+ * Create the necessary GLSL rvalues to index into gl_CullDistanceMESA based
+ * on the rvalue previously used to index into gl_CullDistance.
+ *
+ * \param array_index Selects one of the vec4's in gl_CullDistanceMESA
+ * \param swizzle_index Selects a component within the vec4 selected by
+ * array_index.
+ */
+void
+lower_cull_distance_visitor::create_indices(ir_rvalue *old_index,
+ ir_rvalue *&array_index,
+ ir_rvalue *&swizzle_index)
+{
+ void *ctx = ralloc_parent(old_index);
+
+ /* Make sure old_index is a signed int so that the bitwise "shift" and
+ * "and" operations below type check properly.
+ */
+ if (old_index->type != glsl_type::int_type) {
+ assert (old_index->type == glsl_type::uint_type);
+ old_index = new(ctx) ir_expression(ir_unop_u2i, old_index);
+ }
+
+ ir_constant *old_index_constant = old_index->constant_expression_value();
+ if (old_index_constant) {
+ /* 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);
+ } else {
+ /* Create a variable to hold the value of old_index (so that we
+ * don't compute it twice).
+ */
+ ir_variable *old_index_var = new(ctx) ir_variable(
+ glsl_type::int_type, "cull_distance_index", ir_var_temporary);
+ this->base_ir->insert_before(old_index_var);
+ this->base_ir->insert_before(new(ctx) ir_assignment(
+ new(ctx) ir_dereference_variable(old_index_var), old_index));
+
+ /* Create the expression cull_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 cull_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),
+ new(ctx) ir_constant(3));
+ }
+}
+
+
+/**
+ * Determine whether the given rvalue describes an array of 8 floats that
+ * needs to be lowered to an array of 2 vec4's; that is, determine whether it
+ * matches one of the following patterns:
+ *
+ * - gl_CullDistance (if gl_CullDistance is 1D)
+ * - gl_CullDistance[i] (if gl_CullDistance is 2D)
+ */
+bool
+lower_cull_distance_visitor::is_cull_distance_vec8(ir_rvalue *ir)
+{
+ /* Note that geometry shaders contain gl_CullDistance 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_cull_distance_1d_var and
+ * this->old_cull_distance_2d_var to be non-NULL in the same shader.
+ */
+
+ if (this->old_cull_distance_1d_var) {
+ ir_dereference_variable *var_ref = ir->as_dereference_variable();
+ if (var_ref && var_ref->var == this->old_cull_distance_1d_var)
+ return true;
+ }
+ if (this->old_cull_distance_2d_var) {
+ /* 2D cull distance is only possible as a geometry input */
+ assert(this->shader_stage == MESA_SHADER_GEOMETRY);
+
+ ir_dereference_array *array_ref = ir->as_dereference_array();
+ if (array_ref) {
+ ir_dereference_variable *var_ref =
+ array_ref->array->as_dereference_variable();
+ if (var_ref && var_ref->var == this->old_cull_distance_2d_var)
+ return true;
+ }
+ }
+ return false;
+}
+
+
+/**
+ * If the given ir satisfies is_cull_distance_vec8(), return new ir
+ * representing its lowered equivalent. That is, map:
+ *
+ * - gl_CullDistance => gl_CullDistanceMESA (if gl_CullDistance is 1D)
+ * - gl_CullDistance[i] => gl_CullDistanceMESA[i] (if gl_CullDistance is 2D)
+ *
+ * Otherwise return NULL.
+ */
+ir_rvalue *
+lower_cull_distance_visitor::lower_cull_distance_vec8(ir_rvalue *ir)
+{
+ if (this->old_cull_distance_1d_var) {
+ ir_dereference_variable *var_ref = ir->as_dereference_variable();
+ if (var_ref && var_ref->var == this->old_cull_distance_1d_var) {
+ return new(ralloc_parent(ir))
+ ir_dereference_variable(this->new_cull_distance_1d_var);
+ }
+ }
+ if (this->old_cull_distance_2d_var) {
+ /* 2D cull distance is only possible as a geometry input */
+ assert(this->shader_stage == MESA_SHADER_GEOMETRY);
+
+ ir_dereference_array *array_ref = ir->as_dereference_array();
+ if (array_ref) {
+ ir_dereference_variable *var_ref =
+ array_ref->array->as_dereference_variable();
+ if (var_ref && var_ref->var == this->old_cull_distance_2d_var) {
+ return new(ralloc_parent(ir))
+ ir_dereference_array(this->new_cull_distance_2d_var,
+ array_ref->array_index);
+ }
+ }
+ }
+ return NULL;
+}
+
+
+void
+lower_cull_distance_visitor::handle_rvalue(ir_rvalue **rv)
+{
+ if (*rv == NULL)
+ return;
+
+ ir_dereference_array *const array_deref = (*rv)->as_dereference_array();
+ if (array_deref == NULL)
+ return;
+
+ /* Replace any expression that indexes one of the floats in gl_CullDistance
+ * with an expression that indexes into one of the vec4's in
+ * gl_CullDistanceMESA and accesses the appropriate component.
+ */
+ ir_rvalue *lowered_vec8 =
+ this->lower_cull_distance_vec8(array_deref->array);
+ if (lowered_vec8 != NULL) {
+ this->progress = true;
+ ir_rvalue *array_index;
+ ir_rvalue *swizzle_index;
+ this->create_indices(array_deref->array_index, array_index, swizzle_index);
+ void *mem_ctx = ralloc_parent(array_deref);
+
+ ir_dereference_array *const new_array_deref =
+ new(mem_ctx) ir_dereference_array(lowered_vec8, array_index);
+
+ ir_expression *const expr =
+ new(mem_ctx) ir_expression(ir_binop_vector_extract,
+ new_array_deref,
+ swizzle_index);
+
+ *rv = expr;
+ }
+}
+
+void
+lower_cull_distance_visitor::fix_lhs(ir_assignment *ir)
+{
+ if (ir->lhs->ir_type == ir_type_expression) {
+ void *mem_ctx = ralloc_parent(ir);
+ ir_expression *const expr = (ir_expression *) ir->lhs;
+
+ /* The expression must be of the form:
+ *
+ * (vector_extract gl_CullDistanceMESA[i], j).
+ */
+ assert(expr->operation == ir_binop_vector_extract);
+ assert(expr->operands[0]->ir_type == ir_type_dereference_array);
+ assert(expr->operands[0]->type == glsl_type::vec4_type);
+
+ ir_dereference *const new_lhs = (ir_dereference *) expr->operands[0];
+ ir->rhs = new(mem_ctx) ir_expression(ir_triop_vector_insert,
+ glsl_type::vec4_type,
+ new_lhs->clone(mem_ctx, NULL),
+ ir->rhs,
+ expr->operands[1]);
+ ir->set_lhs(new_lhs);
+ ir->write_mask = WRITEMASK_XYZW;
+ }
+}
+
+/**
+ * Replace any assignment having the 1D gl_CullDistance (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_CullDistanceMESA as appropriate.
+ *
+ * We need to do a similar replacement for 2D gl_CullDistance, 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.:
+ *
+ * foo = gl_in[i].gl_CullDistance
+ */
+ir_visitor_status
+lower_cull_distance_visitor::visit_leave(ir_assignment *ir)
+{
+ /* First invoke the base class visitor. This causes handle_rvalue() to be
+ * called on ir->rhs and ir->condition.
+ */
+ ir_rvalue_visitor::visit_leave(ir);
+
+ if (this->is_cull_distance_vec8(ir->lhs) ||
+ this->is_cull_distance_vec8(ir->rhs)) {
+ /* LHS or RHS of the assignment is the entire 1D gl_CullDistance array
+ * (or a 1D slice of a 2D gl_CullDistance input array). Since we are
+ * reshaping gl_CullDistance 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.
+ *
+ * Note: to unroll into element-by-element assignments, we need to make
+ * clones of the LHS and RHS. This is safe because expressions and
+ * l-values are side-effect free.
+ */
+ void *ctx = ralloc_parent(ir);
+ int array_size = ir->lhs->type->array_size();
+ for (int i = 0; i < array_size; ++i) {
+ ir_dereference_array *new_lhs = new(ctx) ir_dereference_array(
+ ir->lhs->clone(ctx, NULL), new(ctx) ir_constant(i));
+ ir_dereference_array *new_rhs = new(ctx) ir_dereference_array(
+ ir->rhs->clone(ctx, NULL), new(ctx) ir_constant(i));
+ this->handle_rvalue((ir_rvalue **) &new_rhs);
+
+ /* Handle the LHS after creating the new assignment. This must
+ * happen in this order because handle_rvalue may replace the old LHS
+ * with an ir_expression of ir_binop_vector_extract. Since this is
+ * not a valide l-value, this will cause an assertion in the
+ * ir_assignment constructor to fail.
+ *
+ * If this occurs, replace the mangled LHS with a dereference of the
+ * vector, and replace the RHS with an ir_triop_vector_insert.
+ */
+ ir_assignment *const assign = new(ctx) ir_assignment(new_lhs, new_rhs);
+ this->handle_rvalue((ir_rvalue **) &assign->lhs);
+ this->fix_lhs(assign);
+
+ this->base_ir->insert_before(assign);
+ }
+ ir->remove();
+
+ return visit_continue;
+ }
+
+ /* Handle the LHS as if it were an r-value. Normally
+ * rvalue_visit(ir_assignment *) only visits the RHS, but we need to lower
+ * expressions in the LHS as well.
+ *
+ * This may cause the LHS to get replaced with an ir_expression of
+ * ir_binop_vector_extract. If this occurs, replace it with a dereference
+ * of the vector, and replace the RHS with an ir_triop_vector_insert.
+ */
+ handle_rvalue((ir_rvalue **)&ir->lhs);
+ this->fix_lhs(ir);
+
+ return rvalue_visit(ir);
+}
+
+
+/**
+ * Set up base_ir properly and call visit_leave() on a newly created
+ * ir_assignment node. This is used in cases where we have to insert an
+ * ir_assignment in a place where we know the hierarchical visitor won't see
+ * it.
+ */
+void
+lower_cull_distance_visitor::visit_new_assignment(ir_assignment *ir)
+{
+ ir_instruction *old_base_ir = this->base_ir;
+ this->base_ir = ir;
+ ir->accept(this);
+ this->base_ir = old_base_ir;
+}
+
+
+/**
+ * If a 1D gl_CullDistance 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_CullDistance. Each of these
+ * assignments is then lowered to refer to gl_CullDistanceMESA.
+ *
+ * We need to do a similar replacement for 2D gl_CullDistance, 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.:
+ *
+ * foo(gl_in[i].gl_CullDistance)
+ */
+ir_visitor_status
+lower_cull_distance_visitor::visit_leave(ir_call *ir)
+{
+ void *ctx = ralloc_parent(ir);
+
+ const exec_node *formal_param_node = ir->callee->parameters.head;
+ const exec_node *actual_param_node = ir->actual_parameters.head;
+ while (!actual_param_node->is_tail_sentinel()) {
+ ir_variable *formal_param = (ir_variable *) formal_param_node;
+ ir_rvalue *actual_param = (ir_rvalue *) actual_param_node;
+
+ /* Advance formal_param_node and actual_param_node now so that we can
+ * safely replace actual_param with another node, if necessary, below.
+ */
+ formal_param_node = formal_param_node->next;
+ actual_param_node = actual_param_node->next;
+
+ if (this->is_cull_distance_vec8(actual_param)) {
+ /* User is trying to pass the whole 1D gl_CullDistance array (or a 1D
+ * slice of a 2D gl_CullDistance array) to a function call. Since we
+ * are reshaping gl_CullDistance 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_cull_distance = new(ctx) ir_variable(
+ actual_param->type, "temp_cull_distance", ir_var_temporary);
+ this->base_ir->insert_before(temp_cull_distance);
+ actual_param->replace_with(
+ new(ctx) ir_dereference_variable(temp_cull_distance));
+ if (formal_param->data.mode == ir_var_function_in
+ || formal_param->data.mode == ir_var_function_inout) {
+ /* Copy from gl_CullDistance 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_cull_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_CullDistance 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_cull_distance));
+ this->base_ir->insert_after(new_assignment);
+ this->visit_new_assignment(new_assignment);
+ }
+ }
+ }
+
+ return rvalue_visit(ir);
+}
+
+
+bool
+lower_cull_distance(gl_shader *shader)
+{
+ lower_cull_distance_visitor v(shader->Stage);
+
+ visit_list_elements(&v, shader->ir);
+
+ if (v.new_cull_distance_1d_var)
+ shader->symbols->add_variable(v.new_cull_distance_1d_var);
+ if (v.new_cull_distance_2d_var)
+ shader->symbols->add_variable(v.new_cull_distance_2d_var);
+
+ return v.progress;
+}
--
2.4.1
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