[Mesa-dev] [PATCH 25/46] glsl: lower gl_TessLevel* from float[n] to vecn.
Marek Olšák
maraeo at gmail.com
Thu Jul 16 11:43:44 PDT 2015
On Sat, Jun 20, 2015 at 12:08 AM, Kenneth Graunke <kenneth at whitecape.org> wrote:
> On Wednesday, June 17, 2015 01:01:21 AM Marek Olšák wrote:
>> From: Fabian Bieler <fabianbieler at fastmail.fm>
>>
>> Similar to gl_ClipDistance -> gl_ClipDistanceMESA
>> ---
>> src/glsl/Makefile.sources | 1 +
>> src/glsl/ir_optimization.h | 1 +
>> src/glsl/link_varyings.cpp | 51 +++-
>> src/glsl/link_varyings.h | 13 +-
>> src/glsl/linker.cpp | 4 +
>> src/glsl/lower_tess_level.cpp | 462 ++++++++++++++++++++++++++++++++
>> src/mesa/drivers/dri/i965/brw_context.c | 1 +
>> src/mesa/main/mtypes.h | 1 +
>> 8 files changed, 521 insertions(+), 13 deletions(-)
>> create mode 100644 src/glsl/lower_tess_level.cpp
>>
>> diff --git a/src/glsl/Makefile.sources b/src/glsl/Makefile.sources
>> index d784a81..b3b84d6 100644
>> --- a/src/glsl/Makefile.sources
>> +++ b/src/glsl/Makefile.sources
>> @@ -154,6 +154,7 @@ LIBGLSL_FILES = \
>> lower_packed_varyings.cpp \
>> lower_named_interface_blocks.cpp \
>> lower_packing_builtins.cpp \
>> + lower_tess_level.cpp \
>> lower_texture_projection.cpp \
>> lower_variable_index_to_cond_assign.cpp \
>> lower_vec_index_to_cond_assign.cpp \
>> diff --git a/src/glsl/ir_optimization.h b/src/glsl/ir_optimization.h
>> index e6939f3..688a5e1 100644
>> --- a/src/glsl/ir_optimization.h
>> +++ b/src/glsl/ir_optimization.h
>> @@ -132,6 +132,7 @@ bool optimize_split_arrays(exec_list *instructions, bool linked);
>> bool lower_offset_arrays(exec_list *instructions);
>> void optimize_dead_builtin_variables(exec_list *instructions,
>> enum ir_variable_mode other);
>> +bool lower_tess_level(gl_shader *shader);
>>
>> bool lower_vertex_id(gl_shader *shader);
>>
>> diff --git a/src/glsl/link_varyings.cpp b/src/glsl/link_varyings.cpp
>> index 373d337..d439b62 100644
>> --- a/src/glsl/link_varyings.cpp
>> +++ b/src/glsl/link_varyings.cpp
>> @@ -318,7 +318,7 @@ 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_mesa_var = none;
>
> This seems like a bad name..."is_foo" suggests a boolean (rather than an
> enum), and "mesa_var" is pretty generic. Perhaps calling it
> "lowered_builtin_array_variable" would be better?
>
>> this->skip_components = 0;
>> this->next_buffer_separator = false;
>> this->matched_candidate = NULL;
>> @@ -367,8 +367,15 @@ tfeedback_decl::init(struct gl_context *ctx, const void *mem_ctx,
>> */
>> if (ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].LowerClipDistance &&
>> strcmp(this->var_name, "gl_ClipDistance") == 0) {
>> - this->is_clip_distance_mesa = true;
>> + this->is_mesa_var = clip_distance;
>> }
>> +
>> + if (ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].LowerTessLevel &&
>> + (strcmp(this->var_name, "gl_TessLevelOuter") == 0))
>> + this->is_mesa_var = tess_level_outer;
>> + if (ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].LowerTessLevel &&
>> + (strcmp(this->var_name, "gl_TessLevelInner") == 0))
>> + this->is_mesa_var = tess_level_inner;
>
> Using ShaderCompilerOptions[MESA_SHADER_VERTEX] for LowerTessLevel seems
> odd - perhaps LowerClipDistance and LowerTessLevel really shouldn't be
> per-stage options, and just live in ctx->Const? *shrug*
>
>> }
>>
>>
>> @@ -415,9 +422,22 @@ 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 ?
>> - prog->LastClipDistanceArraySize :
>> - this->matched_candidate->type->array_size();
>> + unsigned actual_array_size;
>> + switch (this->is_mesa_var) {
>> + case clip_distance:
>> + actual_array_size = prog->LastClipDistanceArraySize;
>> + break;
>> + case tess_level_outer:
>> + actual_array_size = 4;
>> + break;
>> + case tess_level_inner:
>> + actual_array_size = 2;
>> + break;
>> + case none:
>> + default:
>> + actual_array_size = this->matched_candidate->type->array_size();
>> + break;
>> + }
>>
>> if (this->is_subscripted) {
>> /* Check array bounds. */
>> @@ -428,7 +448,7 @@ 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_mesa_var ?
>> 1 : vector_elements * matrix_cols;
>> fine_location += array_elem_size * this->array_subscript;
>> this->size = 1;
>> @@ -437,7 +457,7 @@ 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_mesa_var)
>> this->type = GL_FLOAT;
>> else
>> this->type = this->matched_candidate->type->fields.array->gl_type;
>> @@ -560,8 +580,21 @@ const tfeedback_candidate *
>> tfeedback_decl::find_candidate(gl_shader_program *prog,
>> hash_table *tfeedback_candidates)
>> {
>> - const char *name = this->is_clip_distance_mesa
>> - ? "gl_ClipDistanceMESA" : this->var_name;
>> + const char *name = this->var_name;
>> + switch (this->is_mesa_var) {
>> + case none:
>> + name = this->var_name;
>> + break;
>> + case clip_distance:
>> + name = "gl_ClipDistanceMESA";
>> + break;
>> + case tess_level_outer:
>> + name = "gl_TessLevelOuterMESA";
>> + break;
>> + case tess_level_inner:
>> + name = "gl_TessLevelInnerMESA";
>> + break;
>> + }
>> this->matched_candidate = (const tfeedback_candidate *)
>> hash_table_find(tfeedback_candidates, name);
>> if (!this->matched_candidate) {
>> diff --git a/src/glsl/link_varyings.h b/src/glsl/link_varyings.h
>> index afc16a8..e0d57ce 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_mesa_var)
>> return this->size;
>> else
>> return this->vector_elements * this->matrix_columns * this->size;
>> @@ -161,10 +161,15 @@ private:
>> unsigned array_subscript;
>>
>> /**
>> - * True if the variable is gl_ClipDistance and the driver lowers
>> - * gl_ClipDistance to gl_ClipDistanceMESA.
>> + * Non-zero if the variable is gl_ClipDistance, glTessLevelOuter or
>> + * gl_TessLevelInner and the driver lowers it to gl_*MESA.
>> */
>> - bool is_clip_distance_mesa;
>> + enum {
>> + none,
>> + clip_distance,
>> + tess_level_outer,
>> + tess_level_inner,
>> + } is_mesa_var;
>>
>> /**
>> * The vertex shader output location that the linker assigned for this
>> diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
>> index 49a88b9..acf6f81 100644
>> --- a/src/glsl/linker.cpp
>> +++ b/src/glsl/linker.cpp
>> @@ -3224,6 +3224,10 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
>> lower_clip_distance(prog->_LinkedShaders[i]);
>> }
>>
>> + if (ctx->Const.ShaderCompilerOptions[i].LowerTessLevel) {
>> + lower_tess_level(prog->_LinkedShaders[i]);
>> + }
>> +
>> while (do_common_optimization(prog->_LinkedShaders[i]->ir, true, false,
>> &ctx->Const.ShaderCompilerOptions[i],
>> ctx->Const.NativeIntegers))
>> diff --git a/src/glsl/lower_tess_level.cpp b/src/glsl/lower_tess_level.cpp
>> new file mode 100644
>> index 0000000..47ff93e
>> --- /dev/null
>> +++ b/src/glsl/lower_tess_level.cpp
>> @@ -0,0 +1,462 @@
>> +/*
>> + * Copyright © 2014 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
>> +
>> + *
>> + * 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_tess_level.cpp
>> + *
>> + * This pass accounts for the difference between the way gl_TessLevelOuter
>> + * and gl_TessLevelInner is declared in standard GLSL (as an array of
>> + * floats), and the way it is frequently implemented in hardware (as a vec4
>> + * and vec2).
>> + *
>> + * The declaration of gl_TessLevel* is replaced with a declaration
>> + * of gl_TessLevel*MESA, and any references to gl_TessLevel* are
>> + * translated to refer to gl_TessLevel*MESA with the appropriate
>> + * swizzling of array indices. For instance:
>> + *
>> + * gl_TessLevelOuter[i]
>> + *
>> + * is translated into:
>> + *
>> + * gl_TessLevelOuterMESA[i]
>> + *
>> + * Since some hardware may not internally represent gl_TessLevel* as a pair
>> + * of vec4's, this lowering pass is optional. To enable it, set the
>> + * LowerTessLevel 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_tess_level_visitor : public ir_rvalue_visitor {
>> +public:
>> + explicit lower_tess_level_visitor(gl_shader_stage shader_stage)
>> + : progress(false), old_tess_level_outer_var(NULL),
>> + old_tess_level_inner_var(NULL), new_tess_level_outer_var(NULL),
>> + new_tess_level_inner_var(NULL), shader_stage(shader_stage)
>> + {
>> + }
>> +
>> + virtual ir_visitor_status visit(ir_variable *);
>> + bool is_tess_level_array(ir_rvalue *ir);
>> + ir_rvalue *lower_tess_level_array(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_TessLevel*, if found.
>> + */
>> + ir_variable *old_tess_level_outer_var;
>> + ir_variable *old_tess_level_inner_var;
>> +
>> + /**
>> + * Pointer to the newly-created gl_TessLevel*MESA variables.
>> + */
>> + ir_variable *new_tess_level_outer_var;
>> + ir_variable *new_tess_level_inner_var;
>> +
>> + /**
>> + * Type of shader we are compiling (e.g. MESA_SHADER_TESS_CTRL)
>> + */
>> + const gl_shader_stage shader_stage;
>> +};
>> +
>> +} /* anonymous namespace */
>> +
>> +/**
>> + * Replace any declaration of gl_TessLevel* as an array of floats with a
>> + * declaration of gl_TessLevel*MESA as a vec4.
>> + */
>> +ir_visitor_status
>> +lower_tess_level_visitor::visit(ir_variable *ir)
>> +{
>> + if ((!ir->name) ||
>> + ((strcmp(ir->name, "gl_TessLevelInner") != 0) &&
>> + (strcmp(ir->name, "gl_TessLevelOuter") != 0)))
>> + return visit_continue;
>> +
>> + assert (ir->type->is_array());
>> +
>> + if (strcmp(ir->name, "gl_TessLevelOuter") == 0) {
>> + if (this->old_tess_level_outer_var)
>> + return visit_continue;
>> +
>> + old_tess_level_outer_var = ir;
>> + assert(ir->type->fields.array == glsl_type::float_type);
>> +
>> + /* Clone the old var so that we inherit all of its properties */
>> + new_tess_level_outer_var = ir->clone(ralloc_parent(ir), NULL);
>> +
>> + /* And change the properties that we need to change */
>> + new_tess_level_outer_var->name = ralloc_strdup(new_tess_level_outer_var,
>> + "gl_TessLevelOuterMESA");
>> + new_tess_level_outer_var->type = glsl_type::vec4_type;
>> + new_tess_level_outer_var->data.max_array_access = 0;
>> +
>> + ir->replace_with(new_tess_level_outer_var);
>> + } else if (strcmp(ir->name, "gl_TessLevelInner") == 0) {
>> + if (this->old_tess_level_inner_var)
>> + return visit_continue;
>> +
>> + old_tess_level_inner_var = ir;
>> + assert(ir->type->fields.array == glsl_type::float_type);
>> +
>> + /* Clone the old var so that we inherit all of its properties */
>> + new_tess_level_inner_var = ir->clone(ralloc_parent(ir), NULL);
>> +
>> + /* And change the properties that we need to change */
>> + new_tess_level_inner_var->name = ralloc_strdup(new_tess_level_inner_var,
>> + "gl_TessLevelInnerMESA");
>> + new_tess_level_inner_var->type = glsl_type::vec2_type;
>> + new_tess_level_inner_var->data.max_array_access = 0;
>> +
>> + ir->replace_with(new_tess_level_inner_var);
>> + } else {
>> + assert(0);
>> + }
>> +
>> + this->progress = true;
>> +
>> + return visit_continue;
>> +}
>> +
>> +
>> +/**
>> + * Determine whether the given rvalue describes an array of floats that
>> + * needs to be lowered to a vec4; that is, determine whether it
>> + * matches one of the following patterns:
>> + *
>> + * - gl_TessLevelOuter
>> + * - gl_TessLevelInner
>> + */
>> +bool
>> +lower_tess_level_visitor::is_tess_level_array(ir_rvalue *ir)
>> +{
>> + if (!ir->type->is_array())
>> + return false;
>> + if (ir->type->fields.array != glsl_type::float_type)
>> + return false;
>> +
>> + if (this->old_tess_level_outer_var) {
>> + if (ir->variable_referenced() == this->old_tess_level_outer_var)
>> + return true;
>> + }
>> + if (this->old_tess_level_inner_var) {
>> + if (ir->variable_referenced() == this->old_tess_level_inner_var)
>> + return true;
>> + }
>> + return false;
>> +}
>> +
>> +
>> +/**
>> + * If the given ir satisfies is_tess_level_array(), return new ir
>> + * representing its lowered equivalent. That is, map:
>> + *
>> + * - gl_TessLevelOuter => gl_TessLevelOuterMESA
>> + * - gl_TessLevelInner => gl_TessLevelInnerMESA
>> + *
>> + * Otherwise return NULL.
>> + */
>> +ir_rvalue *
>> +lower_tess_level_visitor::lower_tess_level_array(ir_rvalue *ir)
>> +{
>> + if (!ir->type->is_array())
>> + return NULL;
>> + if (ir->type->fields.array != glsl_type::float_type)
>> + return NULL;
>> +
>> + ir_variable **new_var = NULL;
>> +
>> + if (this->old_tess_level_outer_var) {
>> + if (ir->variable_referenced() == this->old_tess_level_outer_var)
>> + new_var = &this->new_tess_level_outer_var;
>> + }
>> + if (this->old_tess_level_inner_var) {
>> + if (ir->variable_referenced() == this->old_tess_level_inner_var)
>> + new_var = &this->new_tess_level_inner_var;
>> + }
>> +
>> + if (new_var == NULL)
>> + return NULL;
>> +
>> + assert(ir->as_dereference_variable());
>> + return new(ralloc_parent(ir)) ir_dereference_variable(*new_var);
>> +}
>> +
>> +
>> +void
>> +lower_tess_level_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_TessLevel*
>> + * with an expression that indexes into one of the vec4's
>> + * gl_TessLevel*MESA and accesses the appropriate component.
>> + */
>> + ir_rvalue *lowered_vec4 =
>> + this->lower_tess_level_array(array_deref->array);
>> + if (lowered_vec4 != NULL) {
>> + this->progress = true;
>> + void *mem_ctx = ralloc_parent(array_deref);
>> +
>> + ir_expression *const expr =
>> + new(mem_ctx) ir_expression(ir_binop_vector_extract,
>> + lowered_vec4,
>> + array_deref->array_index);
>> +
>> + *rv = expr;
>> + }
>> +}
>> +
>> +void
>> +lower_tess_level_visitor::fix_lhs(ir_assignment *ir)
>> +{
>> + if (ir->lhs->ir_type != ir_type_expression)
>> + return;
>> + void *mem_ctx = ralloc_parent(ir);
>> + ir_expression *const expr = (ir_expression *) ir->lhs;
>> +
>> + /* The expression must be of the form:
>> + *
>> + * (vector_extract gl_TessLevel*MESA, j).
>> + */
>> + assert(expr->operation == ir_binop_vector_extract);
>> + assert(expr->operands[0]->ir_type == ir_type_dereference_variable);
>> + assert((expr->operands[0]->type == glsl_type::vec4_type) ||
>> + (expr->operands[0]->type == glsl_type::vec2_type));
>> +
>> + ir_dereference *const new_lhs = (ir_dereference *) expr->operands[0];
>> +
>> + ir_constant *old_index_constant = expr->operands[1]->constant_expression_value();
>> + if (!old_index_constant) {
>> + ir->rhs = new(mem_ctx) ir_expression(ir_triop_vector_insert,
>> + glsl_type::vec4_type,
>
> This seems wrong, shouldn't it be vec2 sometimes? i.e. I think we want
> expr->operands[0]->type here...
>
>> + new_lhs->clone(mem_ctx, NULL),
>> + ir->rhs,
>> + expr->operands[1]);
>> + }
>> + ir->set_lhs(new_lhs);
>> +
>> + if (old_index_constant) {
>> + /* gl_TessLevel* is being accessed via a constant index. Don't bother
>> + * creating a vector insert op. Just use a write mask.
>> + */
>> + ir->write_mask = 1 << old_index_constant->get_int_component(0);
>> + } else {
>> + if(expr->operands[0]->type == glsl_type::vec4_type)
>> + ir->write_mask = WRITEMASK_XYZW;
>> + else
>> + ir->write_mask = WRITEMASK_XY;
>
> This could be shortened to:
>
> ir->writemask = (1 << expr->operands[0]->type->vector_elements) - 1;
>
>> + }
>> +}
>> +
>> +/**
>> + * Replace any assignment having a gl_TessLevel* (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_TessLevel*MESA as appropriate.
>> + */
>> +ir_visitor_status
>> +lower_tess_level_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_tess_level_array(ir->lhs) ||
>> + this->is_tess_level_array(ir->rhs)) {
>> + /* LHS or RHS of the assignment is the entire gl_TessLevel* array.
>> + * Since we are
>> + * reshaping gl_TessLevel* from an array of floats to a
>> + * vec4, 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_tess_level_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 gl_TessLevel* 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_TessLevel*. Each of these
>> + * assignments is then lowered to refer to gl_TessLevel*MESA.
>> + */
>> +ir_visitor_status
>> +lower_tess_level_visitor::visit_leave(ir_call *ir)
>> +{
>
> It seems odd that we're handling calls - though the old clip distance
> code seems to do that too. This is post-linking, so calls should have
> been inlined. We use ir_call for a couple of "intrinsics" (for atomic
> counters and image load/store) that never get inlined, but those should
> never match this signature.
>
> i.e. I wonder if we can just delete all of this code.
I don't have an opinion. Your call. Or it can be done later.
Marek
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