| /* |
| * 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_in_list_safe(ir_variable, var, instructions) { |
| if (var->ir_type != ir_type_variable || 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 (!is_gl_identifier(var->name)) |
| 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. |
| * |
| * For compute shaders, gl_GlobalInvocationID has some dependencies, so |
| * we avoid removing these dependencies. |
| * |
| * We also avoid removing gl_GlobalInvocationID at this stage because it |
| * might be used by a linked shader. In this case it still needs to be |
| * initialized by the main function. |
| * |
| * gl_GlobalInvocationID = |
| * gl_WorkGroupID * gl_WorkGroupSize + gl_LocalInvocationID |
| * |
| * Similarly, we initialize gl_LocalInvocationIndex in the main function: |
| * |
| * gl_LocalInvocationIndex = |
| * gl_LocalInvocationID.z * gl_WorkGroupSize.x * gl_WorkGroupSize.y + |
| * gl_LocalInvocationID.y * gl_WorkGroupSize.x + |
| * gl_LocalInvocationID.x; |
| * |
| * Matrix uniforms with "Transpose" are not eliminated because there's |
| * an optimization pass that can turn references to the regular matrix |
| * into references to the transpose matrix. Eliminating the transpose |
| * matrix would cause that pass to generate references to undeclareds |
| * variables (thank you, ir_validate). |
| * |
| * It doesn't seem worth the effort to track when the transpose could be |
| * eliminated (i.e., when the non-transpose was eliminated). |
| */ |
| if (strcmp(var->name, "gl_ModelViewProjectionMatrix") == 0 |
| || strcmp(var->name, "gl_Vertex") == 0 |
| || strcmp(var->name, "gl_WorkGroupID") == 0 |
| || strcmp(var->name, "gl_WorkGroupSize") == 0 |
| || strcmp(var->name, "gl_LocalInvocationID") == 0 |
| || strcmp(var->name, "gl_GlobalInvocationID") == 0 |
| || strcmp(var->name, "gl_LocalInvocationIndex") == 0 |
| || strstr(var->name, "Transpose") != NULL) |
| continue; |
| |
| var->remove(); |
| } |
| } |