Re: [Mesa-dev] [PATCH 15/21] linker: Modify cross_validate_outputs_to_inputs to match using explicit locations
Ian Romanick i...@freedesktop.org writes:
From: Ian Romanick ian.d.roman...@intel.com
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.
diff --git a/src/glsl/link_varyings.cpp b/src/glsl/link_varyings.cpp
index e5c2751..232e230 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;
Relevant citation:
A program will fail to link if any two fragment shader output variables
are assigned to the same location and index, or if any two output
variables from the same non-fragment shader stage are assigned to the same
location.
I think this has a problem of not throwing an error when your explicit
location array overlaps your explicit location scalar, but I don't think
it's that important.
@@ -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 +1105,13 @@ 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) {
+/* FINISHME: If the input is an interface, array, or structure,
it
+ * FINISHME: will use multiple slots.
+ */
+consumer_inputs_with_locations[input_var-data.location] =
+ input_var;
I think this FINISHME shouldn't be there. It looks like
assign_varying_locations() only cares about finding the ir_variable at
the start of a contiguous location block. My reasoning:
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.
pgp1J3otjuldz.pgp
Description: PGP signature
___
mesa-dev mailing
Re: [Mesa-dev] [PATCH 15/21] linker: Modify cross_validate_outputs_to_inputs to match using explicit locations
On 04/30/2014 12:40 PM, Eric Anholt wrote:
Ian Romanick i...@freedesktop.org writes:
From: Ian Romanick ian.d.roman...@intel.com
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.
diff --git a/src/glsl/link_varyings.cpp b/src/glsl/link_varyings.cpp
index e5c2751..232e230 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;
Relevant citation:
A program will fail to link if any two fragment shader output variables
are assigned to the same location and index, or if any two output
variables from the same non-fragment shader stage are assigned to the same
location.
I think this has a problem of not throwing an error when your explicit
location array overlaps your explicit location scalar, but I don't think
it's that important.
I think you're correct on both counts. I'm not sure if the
closed-source drivers enforce this either. More tests.
@@ -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 +1105,13 @@ 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) {
+/* FINISHME: If the input is an interface, array, or structure,
it
+ * FINISHME: will use multiple slots.
+ */
+consumer_inputs_with_locations[input_var-data.location] =
+ input_var;
I think this FINISHME shouldn't be there. It looks like
assign_varying_locations() only cares about finding the ir_variable at
the start of a contiguous location block. My reasoning:
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
