[Mesa-dev] [PATCH v2 1/4] glsl: look for multiple variables simultaneously with find_assignment_visitor
Nicolai Hähnle
nhaehnle at gmail.com
Mon Jul 3 12:34:32 UTC 2017
From: Nicolai Hähnle <nicolai.haehnle at amd.com>
Save some passes over the IR.
v2: redesign to make the users of find_assignments more readable
Reviewed-by: Ian Romanick <ian.d.romanick at intel.com> (v1)
---
src/compiler/glsl/linker.cpp | 120 ++++++++++++++++++++++++++++---------------
1 file changed, 79 insertions(+), 41 deletions(-)
diff --git a/src/compiler/glsl/linker.cpp b/src/compiler/glsl/linker.cpp
index 15295da..4aa4682 100644
--- a/src/compiler/glsl/linker.cpp
+++ b/src/compiler/glsl/linker.cpp
@@ -83,82 +83,120 @@
#include "ir_uniform.h"
#include "builtin_functions.h"
#include "shader_cache.h"
#include "main/shaderobj.h"
#include "main/enums.h"
namespace {
+struct find_variable {
+ const char *name;
+ bool found;
+
+ find_variable(const char *name) : name(name), found(false) {}
+};
+
/**
* Visitor that determines whether or not a variable is ever written.
+ *
+ * Use \ref find_assignments for convenience.
*/
class find_assignment_visitor : public ir_hierarchical_visitor {
public:
- find_assignment_visitor(const char *name)
- : name(name), found(false)
+ find_assignment_visitor(unsigned num_vars,
+ find_variable * const *vars)
+ : num_variables(num_vars), num_found(0), variables(vars)
{
- /* empty */
}
virtual ir_visitor_status visit_enter(ir_assignment *ir)
{
ir_variable *const var = ir->lhs->variable_referenced();
- if (strcmp(name, var->name) == 0) {
- found = true;
- return visit_stop;
- }
-
- return visit_continue_with_parent;
+ return check_variable_name(var->name);
}
virtual ir_visitor_status visit_enter(ir_call *ir)
{
foreach_two_lists(formal_node, &ir->callee->parameters,
actual_node, &ir->actual_parameters) {
ir_rvalue *param_rval = (ir_rvalue *) actual_node;
ir_variable *sig_param = (ir_variable *) formal_node;
if (sig_param->data.mode == ir_var_function_out ||
sig_param->data.mode == ir_var_function_inout) {
ir_variable *var = param_rval->variable_referenced();
- if (var && strcmp(name, var->name) == 0) {
- found = true;
+ if (var && check_variable_name(var->name) == visit_stop)
return visit_stop;
- }
}
}
if (ir->return_deref != NULL) {
ir_variable *const var = ir->return_deref->variable_referenced();
- if (strcmp(name, var->name) == 0) {
- found = true;
+ if (check_variable_name(var->name) == visit_stop)
return visit_stop;
- }
}
return visit_continue_with_parent;
}
- bool variable_found()
+private:
+ ir_visitor_status check_variable_name(const char *name)
{
- return found;
+ for (unsigned i = 0; i < num_variables; ++i) {
+ if (strcmp(variables[i]->name, name) == 0) {
+ if (variables[i]->found) {
+ variables[i]->found = true;
+ if (++num_found >= num_variables)
+ return visit_stop;
+ }
+ break;
+ }
+ }
+
+ return visit_continue_with_parent;
}
private:
- const char *name; /**< Find writes to a variable with this name. */
- bool found; /**< Was a write to the variable found? */
+ unsigned num_variables;
+ unsigned num_found;
+ find_variable * const *variables;
};
+/**
+ * Determine whether or not any of NULL-terminated list of variables is ever
+ * written to.
+ */
+static void
+find_assignments(exec_list *ir, find_variable * const *vars)
+{
+ unsigned num_variables = 0;
+
+ for (find_variable * const *v = vars; *v; ++v)
+ num_variables++;
+
+ find_assignment_visitor visitor(num_variables, vars);
+ visitor.run(ir);
+}
+
+/**
+ * Determine whether or not the given variable is ever written to.
+ */
+static void
+find_assignments(exec_list *ir, find_variable *var)
+{
+ find_assignment_visitor visitor(1, &var);
+ visitor.run(ir);
+}
/**
* Visitor that determines whether or not a variable is ever read.
*/
class find_deref_visitor : public ir_hierarchical_visitor {
public:
find_deref_visitor(const char *name)
: name(name), found(false)
{
/* empty */
@@ -560,61 +598,62 @@ analyze_clip_cull_usage(struct gl_shader_program *prog,
/* From section 7.1 (Vertex Shader Special Variables) of the
* GLSL 1.30 spec:
*
* "It is an error for a shader to statically write both
* gl_ClipVertex and gl_ClipDistance."
*
* This does not apply to GLSL ES shaders, since GLSL ES defines neither
* gl_ClipVertex nor gl_ClipDistance. However with
* GL_EXT_clip_cull_distance, this functionality is exposed in ES 3.0.
*/
- find_assignment_visitor clip_distance("gl_ClipDistance");
- find_assignment_visitor cull_distance("gl_CullDistance");
-
- clip_distance.run(shader->ir);
- cull_distance.run(shader->ir);
+ find_variable gl_ClipDistance("gl_ClipDistance");
+ find_variable gl_CullDistance("gl_CullDistance");
+ find_variable gl_ClipVertex("gl_ClipVertex");
+ find_variable * const variables[] = {
+ &gl_ClipDistance,
+ &gl_CullDistance,
+ !prog->IsES ? &gl_ClipVertex : NULL,
+ NULL
+ };
+ find_assignments(shader->ir, variables);
/* From the ARB_cull_distance spec:
*
* It is a compile-time or link-time error for the set of shaders forming
* a program to statically read or write both gl_ClipVertex and either
* gl_ClipDistance or gl_CullDistance.
*
* This does not apply to GLSL ES shaders, since GLSL ES doesn't define
* gl_ClipVertex.
*/
if (!prog->IsES) {
- find_assignment_visitor clip_vertex("gl_ClipVertex");
-
- clip_vertex.run(shader->ir);
-
- if (clip_vertex.variable_found() && clip_distance.variable_found()) {
+ if (gl_ClipVertex.found && gl_ClipDistance.found) {
linker_error(prog, "%s shader writes to both `gl_ClipVertex' "
"and `gl_ClipDistance'\n",
_mesa_shader_stage_to_string(shader->Stage));
return;
}
- if (clip_vertex.variable_found() && cull_distance.variable_found()) {
+ if (gl_ClipVertex.found && gl_CullDistance.found) {
linker_error(prog, "%s shader writes to both `gl_ClipVertex' "
"and `gl_CullDistance'\n",
_mesa_shader_stage_to_string(shader->Stage));
return;
}
}
- if (clip_distance.variable_found()) {
+ if (gl_ClipDistance.found) {
ir_variable *clip_distance_var =
shader->symbols->get_variable("gl_ClipDistance");
assert(clip_distance_var);
*clip_distance_array_size = clip_distance_var->type->length;
}
- if (cull_distance.variable_found()) {
+ if (gl_CullDistance.found) {
ir_variable *cull_distance_var =
shader->symbols->get_variable("gl_CullDistance");
assert(cull_distance_var);
*cull_distance_array_size = cull_distance_var->type->length;
}
/* From the ARB_cull_distance spec:
*
* It is a compile-time or link-time error for the set of shaders forming
* a program to have the sum of the sizes of the gl_ClipDistance and
* gl_CullDistance arrays to be larger than
@@ -669,23 +708,23 @@ validate_vertex_shader_executable(struct gl_shader_program *prog,
* after being written. This value will be used by primitive
* assembly, clipping, culling, and other fixed functionality
* operations, if present, that operate on primitives after
* vertex processing has occurred. Its value is undefined if
* the vertex shader executable does not write gl_Position."
*
* All GLSL ES Versions are similar to GLSL 1.40--failing to write to
* gl_Position is not an error.
*/
if (prog->data->Version < (prog->IsES ? 300 : 140)) {
- find_assignment_visitor find("gl_Position");
- find.run(shader->ir);
- if (!find.variable_found()) {
+ find_variable gl_Position("gl_Position");
+ find_assignments(shader->ir, &gl_Position);
+ if (!gl_Position.found) {
if (prog->IsES) {
linker_warning(prog,
"vertex shader does not write to `gl_Position'. "
"Its value is undefined. \n");
} else {
linker_error(prog,
"vertex shader does not write to `gl_Position'. \n");
}
return;
}
@@ -715,27 +754,26 @@ validate_tess_eval_shader_executable(struct gl_shader_program *prog,
*
* \param shader Fragment shader executable to be verified
*/
void
validate_fragment_shader_executable(struct gl_shader_program *prog,
struct gl_linked_shader *shader)
{
if (shader == NULL)
return;
- find_assignment_visitor frag_color("gl_FragColor");
- find_assignment_visitor frag_data("gl_FragData");
-
- frag_color.run(shader->ir);
- frag_data.run(shader->ir);
+ find_variable gl_FragColor("gl_FragColor");
+ find_variable gl_FragData("gl_FragData");
+ find_variable * const variables[] = { &gl_FragColor, &gl_FragData, NULL };
+ find_assignments(shader->ir, variables);
- if (frag_color.variable_found() && frag_data.variable_found()) {
+ if (gl_FragColor.found && gl_FragData.found) {
linker_error(prog, "fragment shader writes to both "
"`gl_FragColor' and `gl_FragData'\n");
}
}
/**
* Verify that a geometry shader executable meets all semantic requirements
*
* Also sets prog->Geom.VerticesIn, and info.clip_distance_array_sizeand
* info.cull_distance_array_size as a side effect.
--
2.9.3
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