*/
#include "nir_builder.h"
+#include "program/prog_instruction.h"
-void
-nir_lower_tes_patch_vertices(nir_shader *tes_nir, unsigned patch_vertices)
+static nir_variable *
+make_uniform(nir_shader *nir, const gl_state_index16 *tokens)
{
- nir_foreach_function(function, tes_nir) {
+ /* Note: name must be prefixed with "gl_" to trigger slot based
+ * special handling in uniform setup.
+ */
+ nir_variable *var =
+ nir_variable_create(nir, nir_var_uniform, glsl_int_type(),
+ "gl_PatchVerticesIn");
+ var->num_state_slots = 1;
+ var->state_slots = ralloc_array(var, nir_state_slot, var->num_state_slots);
+ memcpy(var->state_slots[0].tokens, tokens, sizeof(*tokens) * STATE_LENGTH);
+ var->state_slots[0].swizzle = SWIZZLE_XXXX;
+
+ return var;
+}
+
+/**
+ * This pass lowers the load_patch_vertices_in intrinsic.
+ *
+ * - If we statically know the value, we lower it to a constant.
+ * (If a TES is linked against a TCS, the TCS tells us the TES input count.)
+ *
+ * - If not, and we're given Mesa state slots, we lower it to a uniform.
+ *
+ * - Otherwise, we leave it as a system value.
+ *
+ * This pass must be run after nir_lower_system_values().
+ */
+bool
+nir_lower_patch_vertices(nir_shader *nir,
+ unsigned static_count,
+ const gl_state_index16 *uniform_state_tokens)
+{
+ bool progress = false;
+ nir_variable *var = NULL;
+
+ /* If there's no static count and we don't want uniforms, there's no
+ * lowering to do...just bail early.
+ */
+ if (static_count == 0 && !uniform_state_tokens)
+ return false;
+
+ nir_foreach_function(function, nir) {
if (function->impl) {
nir_foreach_block(block, function->impl) {
nir_builder b;
continue;
b.cursor = nir_before_instr(&intr->instr);
- nir_ssa_def *val = nir_imm_int(&b, patch_vertices);
+
+ nir_ssa_def *val = NULL;
+ if (static_count) {
+ val = nir_imm_int(&b, static_count);
+ } else {
+ if (!var)
+ var = make_uniform(nir, uniform_state_tokens);
+
+ val = nir_load_var(&b, var);
+ }
+
+ progress = true;
nir_ssa_def_rewrite_uses(&intr->dest.ssa,
nir_src_for_ssa(val));
nir_instr_remove(instr);
}
}
- nir_metadata_preserve(function->impl, nir_metadata_block_index |
- nir_metadata_dominance);
+ if (progress) {
+ nir_metadata_preserve(function->impl, nir_metadata_block_index |
+ nir_metadata_dominance);
+ }
}
}
+
+ return progress;
}