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authorIan Romanick <ian.d.romanick@intel.com>2013-10-02 12:39:29 -0700
committerIan Romanick <ian.d.romanick@intel.com>2014-05-02 07:19:40 -0700
commit7ff937e5793dc8709c916e043b41142033c8e69e (patch)
treed5eb892659bf47bf335554d8f4fe2ad24b741ddd /src/glsl/link_varyings.cpp
parentd030a3404ca0fedf365cb0fd41eaad7abc8ff132 (diff)
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linker: Modify cross_validate_outputs_to_inputs to match using explicit locations
This will be used for GL_ARB_separate_shader_objects. That extension not only allows separable shaders to rendezvous by location, but it also allows traditionally linked shaders to rendezvous by location. The spec says: 36. How does the behavior of input/output interface matching differ between separable programs and non-separable programs? RESOLVED: The rules for matching individual variables or block members between stages are identical for separable and non-separable programs, with one exception -- matching variables of different type with the same location, as discussed in issue 34, applies only to separable programs. However, the ability to enforce matching requirements differs between program types. In non-separable programs, both sides of an interface are contained in the same linked program. In this case, if the linker detects a mismatch, it will generate a link error. v2: Make sure consumer_inputs_with_locations is initialized when consumer is NULL. Noticed by Chia-I. v3: Rebase on removal of ir_variable::user_location. v4: Replace a (stale) FINISHME with some good explanation comments from Eric. Signed-off-by: Ian Romanick <ian.d.romanick@intel.com> Reviewed-by: Eric Anholt <eric@anholt.net>
Diffstat (limited to 'src/glsl/link_varyings.cpp')
-rw-r--r--src/glsl/link_varyings.cpp88
1 files changed, 80 insertions, 8 deletions
diff --git a/src/glsl/link_varyings.cpp b/src/glsl/link_varyings.cpp
index e5c2751..45f1b10 100644
--- a/src/glsl/link_varyings.cpp
+++ b/src/glsl/link_varyings.cpp
@@ -172,6 +172,7 @@ cross_validate_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.
*/
@@ -181,7 +182,26 @@ cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
if ((var == NULL) || (var->data.mode != ir_var_shader_out))
continue;
- parameters.add_variable(var);
+ if (!var->data.explicit_location
+ || var->data.location < VARYING_SLOT_VAR0)
+ parameters.add_variable(var);
+ else {
+ /* User-defined varyings with explicit locations are handled
+ * differently because they do not need to have matching names.
+ */
+ const unsigned idx = var->data.location - VARYING_SLOT_VAR0;
+
+ if (explicit_locations[idx] != NULL) {
+ linker_error(prog,
+ "%s shader has multiple outputs explicitly "
+ "assigned to location %d\n",
+ _mesa_shader_stage_to_string(producer->Stage),
+ idx);
+ return;
+ }
+
+ explicit_locations[idx] = var;
+ }
}
@@ -220,7 +240,27 @@ cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
front_color, back_color,
consumer->Stage, producer->Stage);
} else {
- ir_variable *const output = parameters.get_variable(input->name);
+ /* The rules for connecting inputs and outputs change in the presence
+ * of explicit locations. In this case, we no longer care about the
+ * names of the variables. Instead, we care only about the
+ * explicitly assigned location.
+ */
+ 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) {
+ linker_error(prog,
+ "%s shader input `%s' with explicit location "
+ "has no matching output\n",
+ _mesa_shader_stage_to_string(consumer->Stage),
+ input->name);
+ }
+ } else {
+ output = parameters.get_variable(input->name);
+ }
+
if (output != NULL) {
cross_validate_types_and_qualifiers(prog, input, output,
consumer->Stage, producer->Stage);
@@ -1051,8 +1091,13 @@ namespace linker {
bool
populate_consumer_input_sets(void *mem_ctx, exec_list *ir,
hash_table *consumer_inputs,
- hash_table *consumer_interface_inputs)
+ hash_table *consumer_interface_inputs,
+ ir_variable *consumer_inputs_with_locations[MAX_VARYING])
{
+ memset(consumer_inputs_with_locations,
+ 0,
+ sizeof(consumer_inputs_with_locations[0]) * MAX_VARYING);
+
foreach_list(node, ir) {
ir_variable *const input_var = ((ir_instruction *) node)->as_variable();
@@ -1060,7 +1105,26 @@ populate_consumer_input_sets(void *mem_ctx, exec_list *ir,
if (input_var->type->is_interface())
return false;
- if (input_var->get_interface_type() != NULL) {
+ if (input_var->data.explicit_location) {
+ /* assign_varying_locations only cares about finding the
+ * ir_variable at the start of a contiguous location block.
+ *
+ * - For !producer, consumer_inputs_with_locations isn't used.
+ *
+ * - For !consumer, consumer_inputs_with_locations is empty.
+ *
+ * For consumer && producer, if you were trying to set some
+ * ir_variable to the middle of a location block on the other side
+ * of producer/consumer, cross_validate_outputs_to_inputs() should
+ * be link-erroring due to either type mismatch or location
+ * overlaps. If the variables do match up, then they've got a
+ * matching data.location and you only looked at
+ * consumer_inputs_with_locations[var->data.location], not any
+ * following entries for the array/structure.
+ */
+ consumer_inputs_with_locations[input_var->data.location] =
+ input_var;
+ } else if (input_var->get_interface_type() != NULL) {
char *const iface_field_name =
ralloc_asprintf(mem_ctx, "%s.%s",
input_var->get_interface_type()->name,
@@ -1087,11 +1151,14 @@ ir_variable *
get_matching_input(void *mem_ctx,
const ir_variable *output_var,
hash_table *consumer_inputs,
- hash_table *consumer_interface_inputs)
+ hash_table *consumer_interface_inputs,
+ ir_variable *consumer_inputs_with_locations[MAX_VARYING])
{
ir_variable *input_var;
- if (output_var->get_interface_type() != NULL) {
+ if (output_var->data.explicit_location) {
+ input_var = consumer_inputs_with_locations[output_var->data.location];
+ } else if (output_var->get_interface_type() != NULL) {
char *const iface_field_name =
ralloc_asprintf(mem_ctx, "%s.%s",
output_var->get_interface_type()->name,
@@ -1210,6 +1277,9 @@ assign_varying_locations(struct gl_context *ctx,
= hash_table_ctor(0, hash_table_string_hash, hash_table_string_compare);
hash_table *consumer_interface_inputs
= hash_table_ctor(0, hash_table_string_hash, hash_table_string_compare);
+ ir_variable *consumer_inputs_with_locations[MAX_VARYING] = {
+ NULL,
+ };
/* Operate in a total of four passes.
*
@@ -1236,7 +1306,8 @@ assign_varying_locations(struct gl_context *ctx,
&& !linker::populate_consumer_input_sets(mem_ctx,
consumer->ir,
consumer_inputs,
- consumer_interface_inputs)) {
+ consumer_interface_inputs,
+ consumer_inputs_with_locations)) {
assert(!"populate_consumer_input_sets failed");
hash_table_dtor(tfeedback_candidates);
hash_table_dtor(consumer_inputs);
@@ -1258,7 +1329,8 @@ assign_varying_locations(struct gl_context *ctx,
ir_variable *const input_var =
linker::get_matching_input(mem_ctx, output_var, consumer_inputs,
- consumer_interface_inputs);
+ consumer_interface_inputs,
+ consumer_inputs_with_locations);
/* If a matching input variable was found, add this ouptut (and the
* input) to the set. If this is a separable program and there is no