ir3: Support variants with different constlen's

This provides the mechanism for compiling variants with a reduced
constlen. The next patch provides the policy for choosing which to
reduce.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5607>

1 files changed, 31 insertions, 0 deletions

diff --git a/src/freedreno/ir3/ir3_shader.h b/src/freedreno/ir3/ir3_shader.h
index 353ce22b243..b2dbc64ce2e 100644
--- a/src/freedreno/ir3/ir3_shader.h
+++ b/src/freedreno/ir3/ir3_shader.h
@@ -299,6 +299,12 @@ struct ir3_shader_key {
 			unsigned tessellation : 2;
 
 			unsigned has_gs : 1;
+
+			/* Whether this variant sticks to the "safe" maximum constlen,
+			 * which guarantees that the combined stages will never go over
+			 * the limit:
+			 */
+			unsigned safe_constlen : 1;
 		};
 		uint32_t global;
 	};
@@ -369,6 +375,9 @@ ir3_shader_key_changes_fs(struct ir3_shader_key *key, struct ir3_shader_key *las
 	if (last_key->ucp_enables != key->ucp_enables)
 		return true;
 
+	if (last_key->safe_constlen != key->safe_constlen)
+		return true;
+
 	return false;
 }
 
@@ -391,6 +400,9 @@ ir3_shader_key_changes_vs(struct ir3_shader_key *key, struct ir3_shader_key *las
 	if (last_key->ucp_enables != key->ucp_enables)
 		return true;
 
+	if (last_key->safe_constlen != key->safe_constlen)
+		return true;
+
 	return false;
 }
 
@@ -668,6 +680,25 @@ ir3_const_state(const struct ir3_shader_variant *v)
 	return v->const_state;
 }
 
+/* Given a variant, calculate the maximum constlen it can have.
+ */
+
+static inline unsigned
+ir3_max_const(const struct ir3_shader_variant *v)
+{
+	const struct ir3_compiler *compiler = v->shader->compiler;
+
+	if (v->shader->type == MESA_SHADER_COMPUTE) {
+		return compiler->max_const_compute;
+	} else if (v->key.safe_constlen) {
+		return compiler->max_const_safe;
+	} else if (v->shader->type == MESA_SHADER_FRAGMENT) {
+		return compiler->max_const_frag;
+	} else {
+		return compiler->max_const_geom;
+	}
+}
+
 void * ir3_shader_assemble(struct ir3_shader_variant *v);
 struct ir3_shader_variant * ir3_shader_get_variant(struct ir3_shader *shader,
 		const struct ir3_shader_key *key, bool binning_pass, bool *created);