On Wed, May 28, 2014 at 6:35 PM, Ian Romanick <i...@freedesktop.org> wrote:
> From: Ian Romanick <ian.d.roman...@intel.com>
>
> After compilation (and before linking) we can eliminate quite a few
> built-in variables. Basically, any uniform or constant (e.g.,
> gl_MaxVertexTextureImageUnits) that isn't used (with one exception) can
> be eliminated. System values, vertex shader inputs (with one
> exception), and fragment shader outputs that are not used and not
> re-declared in the shader text can also be removed.
>
> gl_ModelViewProjectMatrix and gl_Vertex are used by the built-in
> function ftransform. There are some complications with eliminating
> these variables (see the comment in the patch), so they are not
> eliminated.
>
> Reduces the peak ir_variable memory usage in a trimmed apitrace of dota2
> by 3.5MB on 64-bit.
>
> Before: IR MEM: variable usage / name / total: 5327760 894914 6222674
> After: IR MEM: variable usage / name / total: 2156568 318192 2474760
>
> Reduces the peak ir_variable memory usage in a trimmed apitrace of dota2
> by 2.8MB on 32-bit.
>
> Before: IR MEM: variable usage / name / total: 4118280 644100 4762380
> After: IR MEM: variable usage / name / total: 1473408 256871 1730279
>
> Signed-off-by: Ian Romanick <ian.d.roman...@intel.com>
> Suggested-by: Eric Anholt <e...@anholt.net>
> Cc: Eric Anholt <e...@anholt.net>
> Cc: Tapani Pälli <tapani.pa...@intel.com>
> Cc: Eero Tamminen <eero.t.tammi...@intel.com>
> ---
> src/glsl/Makefile.sources | 1 +
> src/glsl/glsl_parser_extras.cpp | 20 ++++++++
> src/glsl/ir_optimization.h | 2 +
> src/glsl/opt_dead_builtin_variables.cpp | 82
> +++++++++++++++++++++++++++++++++
> 4 files changed, 105 insertions(+)
> create mode 100644 src/glsl/opt_dead_builtin_variables.cpp
>
> diff --git a/src/glsl/Makefile.sources b/src/glsl/Makefile.sources
> index 6e230f7..a733323 100644
> --- a/src/glsl/Makefile.sources
> +++ b/src/glsl/Makefile.sources
> @@ -88,6 +88,7 @@ LIBGLSL_FILES = \
> $(GLSL_SRCDIR)/opt_copy_propagation.cpp \
> $(GLSL_SRCDIR)/opt_copy_propagation_elements.cpp \
> $(GLSL_SRCDIR)/opt_cse.cpp \
> + $(GLSL_SRCDIR)/opt_dead_builtin_variables.cpp \
> $(GLSL_SRCDIR)/opt_dead_builtin_varyings.cpp \
> $(GLSL_SRCDIR)/opt_dead_code.cpp \
> $(GLSL_SRCDIR)/opt_dead_code_local.cpp \
> diff --git a/src/glsl/glsl_parser_extras.cpp b/src/glsl/glsl_parser_extras.cpp
> index d3339e7..323cb23 100644
> --- a/src/glsl/glsl_parser_extras.cpp
> +++ b/src/glsl/glsl_parser_extras.cpp
> @@ -1485,6 +1485,26 @@ _mesa_glsl_compile_shader(struct gl_context *ctx,
> struct gl_shader *shader,
> ;
>
> validate_ir_tree(shader->ir);
> +
> + enum ir_variable_mode other;
> + switch (shader->Stage) {
> + case MESA_SHADER_VERTEX:
> + other = ir_var_shader_in;
> + break;
> + case MESA_SHADER_FRAGMENT:
> + other = ir_var_shader_out;
> + break;
> + default:
> + /* Something invalide to ensure optimize_dead_builtin_uniforms
invalid?
> + * doesn't remove anything other than uniforms or constants.
> + */
> + other = ir_var_mode_count;
> + break;
> + }
> +
> + optimize_dead_builtin_variables(shader->ir, other);
> +
> + validate_ir_tree(shader->ir);
> }
>
> if (shader->InfoLog)
> diff --git a/src/glsl/ir_optimization.h b/src/glsl/ir_optimization.h
> index c63921c..2dfd81e 100644
> --- a/src/glsl/ir_optimization.h
> +++ b/src/glsl/ir_optimization.h
> @@ -122,6 +122,8 @@ void lower_named_interface_blocks(void *mem_ctx,
> gl_shader *shader);
> bool optimize_redundant_jumps(exec_list *instructions);
> 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);
>
> ir_rvalue *
> compare_index_block(exec_list *instructions, ir_variable *index,
> diff --git a/src/glsl/opt_dead_builtin_variables.cpp
> b/src/glsl/opt_dead_builtin_variables.cpp
> new file mode 100644
> index 0000000..b68e720
> --- /dev/null
> +++ b/src/glsl/opt_dead_builtin_variables.cpp
> @@ -0,0 +1,82 @@
> +/*
> + * 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
> + * 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.
> + */
> +
> +#include "ir.h"
> +#include "ir_visitor.h"
> +#include "ir_optimization.h"
> +
> +/**
> + * Pre-linking, optimize unused built-in variables
> + *
> + * Uniforms, constants, system values, inputs (vertex shader only), and
> + * outputs (fragment shader only) that are not used can be removed.
> + */
> +void
> +optimize_dead_builtin_variables(exec_list *instructions,
> + enum ir_variable_mode other)
> +{
> + foreach_list_safe(n, instructions) {
> + ir_variable *const var = ((ir_instruction *) n)->as_variable();
> +
> + if (var == NULL || var->data.used)
> + continue;
> +
> + if (var->data.mode != ir_var_uniform
> + && var->data.mode != ir_var_auto
> + && var->data.mode != ir_var_system_value
> + && var->data.mode != other)
> + continue;
> +
> + /* So that linker rules can later be enforced, we cannot elimate
> + * variables that were redeclared in the shader code.
> + */
> + if ((var->data.mode == other || var->data.mode == ir_var_system_value)
> + && var->data.how_declared != ir_var_declared_implicitly)
> + continue;
> +
> + if (strncmp(var->name, "gl_", 3) != 0)
> + continue;
> +
> + /* gl_ModelViewProjectionMatrix and gl_Vertex are special because they
> + * are used by ftransform. No other built-in variable is used by a
> + * built-in function. The forward declarations of these variables in
> + * the built-in function shader does not have the "state slot"
> + * information, so removing these variables from the user shader will
> + * cause problems later.
> + *
> + * gl_ModelViewProjectionMatrixTranspose isn't eliminated because
> + * there's an optimization pass that can turn references to
> + * gl_ModelViewProjectionMatrix into references to
> + * gl_ModelViewProjectionMatrixTranspose. Eliminating
> + * gl_ModelViewProjectionMatrixTranspose would cause that pass to
> + * generate references to an undeclared variable (thank you,
> + * ir_validate).
> + */
> + if (strcmp(var->name, "gl_ModelViewProjectionMatrix") == 0
> + || strcmp(var->name, "gl_ModelViewProjectionMatrixTranspose") == 0
> + || strcmp(var->name, "gl_Vertex") == 0)
> + continue;
> +
> + var->remove();
> + }
> +}
> --
> 1.8.1.4
>
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Series is:
Acked-by: Anuj Phogat <anuj.pho...@gmail.com>
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