aboutsummaryrefslogtreecommitdiffstats
path: root/src/glsl/linker.cpp
diff options
context:
space:
mode:
authorTimothy Arceri <[email protected]>2015-11-21 12:47:25 +1100
committerTimothy Arceri <[email protected]>2015-12-01 12:45:03 +1100
commit12ba6cfba7974cdf4609b146303a5988447d30c2 (patch)
tree9f3c004317ca9cee410a1a8b4954b88079d3f564 /src/glsl/linker.cpp
parent4d64459a92a4c1a64fb7051fd1320c14c1854dcb (diff)
glsl: optimise inputs/outputs with explicit locations
This change allows used defined inputs/outputs with explicit locations to be removed if they are detected to not be used between shaders at link time. To enable this we change the is_unmatched_generic_inout field to be flagged when we have a user defined varying. Previously explicit_location was assumed to be set only in builtins however SSO allows the user to set an explicit location. We then add a function to match explicit locations between shaders. V2: call match_explicit_outputs_to_inputs() after is_unmatched_generic_inout has been initialised. Cc: Gregory Hainaut <[email protected]> Reviewed-by: Tapani Pälli <[email protected]>
Diffstat (limited to 'src/glsl/linker.cpp')
-rw-r--r--src/glsl/linker.cpp82
1 files changed, 70 insertions, 12 deletions
diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index 5ff433ccba9..d2df33d8920 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -631,20 +631,12 @@ link_invalidate_variable_locations(exec_list *ir)
/* ir_variable::is_unmatched_generic_inout is used by the linker while
* connecting outputs from one stage to inputs of the next stage.
- *
- * There are two implicit assumptions here. First, we assume that any
- * built-in variable (i.e., non-generic in or out) will have
- * explicit_location set. Second, we assume that any generic in or out
- * will not have explicit_location set.
- *
- * This second assumption will only be valid until
- * GL_ARB_separate_shader_objects is supported. When that extension is
- * implemented, this function will need some modifications.
*/
- if (!var->data.explicit_location) {
- var->data.is_unmatched_generic_inout = 1;
- } else {
+ if (var->data.explicit_location &&
+ var->data.location < VARYING_SLOT_VAR0) {
var->data.is_unmatched_generic_inout = 0;
+ } else {
+ var->data.is_unmatched_generic_inout = 1;
}
}
}
@@ -2421,6 +2413,7 @@ assign_attribute_or_color_locations(gl_shader_program *prog,
continue;
if (var->data.explicit_location) {
+ var->data.is_unmatched_generic_inout = 0;
if ((var->data.location >= (int)(max_index + generic_base))
|| (var->data.location < 0)) {
linker_error(prog,
@@ -2690,6 +2683,61 @@ assign_attribute_or_color_locations(gl_shader_program *prog,
return true;
}
+/**
+ * Match explicit locations of outputs to inputs and deactivate the
+ * unmatch flag if found so we don't optimise them away.
+ */
+void
+match_explicit_outputs_to_inputs(struct gl_shader_program *prog,
+ gl_shader *producer,
+ gl_shader *consumer)
+{
+ glsl_symbol_table parameters;
+ ir_variable *explicit_locations[MAX_VARYING] = { NULL };
+
+ /* Find all shader outputs in the "producer" stage.
+ */
+ foreach_in_list(ir_instruction, node, producer->ir) {
+ ir_variable *const var = node->as_variable();
+
+ if ((var == NULL) || (var->data.mode != ir_var_shader_out))
+ continue;
+
+ /* Mark output as matched if separate shader with no linked consumer */
+ if (consumer == NULL)
+ var->data.is_unmatched_generic_inout = 0;
+
+ if (var->data.explicit_location &&
+ var->data.location >= VARYING_SLOT_VAR0) {
+ const unsigned idx = var->data.location - VARYING_SLOT_VAR0;
+ if (explicit_locations[idx] == NULL)
+ explicit_locations[idx] = var;
+ }
+ }
+
+ /* Match inputs to outputs */
+ foreach_in_list(ir_instruction, node, consumer->ir) {
+ ir_variable *const input = node->as_variable();
+
+ if ((input == NULL) || (input->data.mode != ir_var_shader_in))
+ continue;
+
+ /* Mark input as matched if separate shader with no linked producer */
+ if (producer == NULL)
+ input->data.is_unmatched_generic_inout = 0;
+
+ ir_variable *output = NULL;
+ if (input->data.explicit_location
+ && input->data.location >= VARYING_SLOT_VAR0) {
+ output = explicit_locations[input->data.location - VARYING_SLOT_VAR0];
+
+ if (output != NULL){
+ input->data.is_unmatched_generic_inout = 0;
+ output->data.is_unmatched_generic_inout = 0;
+ }
+ }
+ }
+}
/**
* Demote shader inputs and outputs that are not used in other stages
@@ -4258,6 +4306,16 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
}
}
+ prev = first;
+ for (unsigned i = prev + 1; i <= MESA_SHADER_FRAGMENT; i++) {
+ if (prog->_LinkedShaders[i] == NULL)
+ continue;
+
+ match_explicit_outputs_to_inputs(prog, prog->_LinkedShaders[prev],
+ prog->_LinkedShaders[i]);
+ prev = i;
+ }
+
if (!assign_attribute_or_color_locations(prog, &ctx->Const,
MESA_SHADER_VERTEX)) {
goto done;