[Mesa-dev] [PATCH 2/2] glsl/cs: Initialize gl_LocalInvocationIndex in main()
Jordan Justen
jordan.l.justen at intel.com
Sun Aug 23 01:50:11 PDT 2015
We initialize gl_LocalInvocationIndex based on the extension spec
formula:
gl_LocalInvocationIndex =
gl_LocalInvocationID.z * gl_WorkGroupSize.x * gl_WorkGroupSize.y +
gl_LocalInvocationID.y * gl_WorkGroupSize.x +
gl_LocalInvocationID.x;
https://www.opengl.org/registry/specs/ARB/compute_shader.txt
Signed-off-by: Jordan Justen <jordan.l.justen at intel.com>
---
src/glsl/builtin_variables.cpp | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/src/glsl/builtin_variables.cpp b/src/glsl/builtin_variables.cpp
index 8f8be90..082c73a 100644
--- a/src/glsl/builtin_variables.cpp
+++ b/src/glsl/builtin_variables.cpp
@@ -1059,6 +1059,7 @@ builtin_variable_generator::generate_cs_special_vars()
add_system_value(SYSTEM_VALUE_WORK_GROUP_ID, glsl_type::uvec3_type,
"gl_WorkGroupID");
add_variable("gl_GlobalInvocationID", glsl_type::uvec3_type, ir_var_auto, 0);
+ add_variable("gl_LocalInvocationIndex", glsl_type::uint_type, ir_var_auto, 0);
/* TODO: finish this. */
}
@@ -1217,6 +1218,11 @@ _mesa_glsl_initialize_variables(exec_list *instructions,
}
+using ir_builder::swizzle_x;
+using ir_builder::swizzle_y;
+using ir_builder::swizzle_z;
+
+
/**
* Initialize compute shader variables with values that are derived from other
* compute shader variable.
@@ -1249,6 +1255,28 @@ initialize_cs_derived_variables(gl_shader *shader,
gl_WorkGroupSize),
gl_LocalInvocationID));
main_sig->body.push_head(inst);
+
+ /* gl_LocalInvocationIndex =
+ * gl_LocalInvocationID.z * gl_WorkGroupSize.x * gl_WorkGroupSize.y +
+ * gl_LocalInvocationID.y * gl_WorkGroupSize.x +
+ * gl_LocalInvocationID.x;
+ */
+ ir_expression *index_z =
+ ir_builder::mul(ir_builder::mul(swizzle_z(gl_LocalInvocationID),
+ swizzle_x(gl_WorkGroupSize)),
+ swizzle_y(gl_WorkGroupSize));
+ ir_expression *index_y =
+ ir_builder::mul(swizzle_y(gl_LocalInvocationID),
+ swizzle_x(gl_WorkGroupSize));
+ ir_expression *index_y_plus_z = ir_builder::add(index_y, index_z);
+ ir_builder::operand index_x(swizzle_x(gl_LocalInvocationID));
+ ir_expression *index_x_plus_y_plus_z =
+ ir_builder::add(index_y_plus_z, index_x);
+ ir_variable *gl_LocalInvocationIndex =
+ shader->symbols->get_variable("gl_LocalInvocationIndex");
+ assert(gl_LocalInvocationIndex);
+ inst = ir_builder::assign(gl_LocalInvocationIndex, index_x_plus_y_plus_z);
+ main_sig->body.push_head(inst);
}
--
2.1.4
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