mesa: sort state vars with constant indexing for ARB programs

This enables merging of state variables such as local parameters
for faster constant uploads. For Trine 2, this mainly sorts local
parameters which are in a random order.

Originally, the next pass added state variables (the code after this code).
If we add them before that, _mesa_add_state_reference will be a no-op
later and will return the ones we added.

So add all state parameters (without indirect indexing). After they are
added, sort them within the parameter list. Then fix their offsets to
correspond to their location after sorting.

Reviewed-by: Zoltán Böszörményi <zboszor@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8183>

diff --git a/src/mesa/program/prog_parameter_layout.c b/src/mesa/program/prog_parameter_layout.c
index db53d7b..1815107 100644 (file)
--- a/src/mesa/program/prog_parameter_layout.c
+++ b/src/mesa/program/prog_parameter_layout.c
@@ -119,8 +119,27 @@ copy_indirect_accessed_array(struct gl_program_parameter_list *src,
 }
 
 
+static int compare_state_var(const void *a1, const void *a2)
+{
+   const struct gl_program_parameter *p1 =
+      (const struct gl_program_parameter *)a1;
+   const struct gl_program_parameter *p2 =
+      (const struct gl_program_parameter *)a2;
+
+   for (unsigned i = 0; i < STATE_LENGTH; i++) {
+      if (p1->StateIndexes[i] != p2->StateIndexes[i])
+         return p1->StateIndexes[i] - p2->StateIndexes[i];
+   }
+   return 0;
+}
+
+
 /**
- * XXX description???
+ * Create the final program parameter list in this order:
+ * - constants and state variables with variable indexing are first
+ * - other constants are next
+ * - other state variables are last and sorted
+ *
  * \return GL_TRUE for success, GL_FALSE for failure
  */
 GLboolean
@@ -173,7 +192,48 @@ _mesa_layout_parameters(struct asm_parser_state *state)
          }
       }
 
-      /* PASS 2:  Move any parameters that are not accessed indirectly from the
+      /* PASS 2:  Add sorted state variables. */
+      if (file == PROGRAM_STATE_VAR) {
+         unsigned first_state_var = layout->NumParameters;
+
+         /* Add state variables with constant indexing. */
+         for (inst = state->inst_head; inst != NULL; inst = inst->next) {
+            for (unsigned i = 0; i < 3; i++) {
+               const struct gl_program_parameter *p;
+               const int idx = inst->SrcReg[i].Base.Index;
+
+               p = &state->prog->Parameters->Parameters[idx];
+
+               if (inst->SrcReg[i].Base.RelAddr ||
+                   inst->SrcReg[i].Base.File <= PROGRAM_OUTPUT ||
+                   inst->SrcReg[i].Base.File >= PROGRAM_WRITE_ONLY ||
+                   p->Type != file)
+                  continue;
+
+               _mesa_add_state_reference(layout, p->StateIndexes);
+            }
+         }
+
+         /* Sort if we have added at least 2 state vars. */
+         if (first_state_var + 2 <= layout->NumParameters) {
+            /* All state vars should be vec4s. */
+            for (unsigned i = first_state_var; i < layout->NumParameters; i++) {
+               assert(layout->Parameters[i].Size == 4);
+               assert(layout->Parameters[i].ValueOffset == i * 4);
+            }
+
+            qsort(layout->Parameters + first_state_var,
+                  layout->NumParameters - first_state_var,
+                  sizeof(layout->Parameters[0]), compare_state_var);
+
+            /* Fix offsets. */
+            for (unsigned i = first_state_var; i < layout->NumParameters; i++) {
+               layout->Parameters[i].ValueOffset = i * 4;
+            }
+         }
+      }
+
+      /* PASS 3:  Move any parameters that are not accessed indirectly from the
        * original parameter list to the new parameter list.
        */
       for (inst = state->inst_head; inst != NULL; inst = inst->next) {