spirv: Only emit functions which are actually used

Instead of emitting absolutely everything, just emit the few functions
that are actually referenced in some way by the entrypoint.  This should
save us quite a bit of time when handed large shader modules containing
many entrypoints.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>

diff --git a/src/compiler/spirv/spirv_to_nir.c b/src/compiler/spirv/spirv_to_nir.c
index c58cf5cbfdf84ccf9d45a5b4d058e63103b172d2..2c4f5b0c93e485b2363ed836b35e33a20c3bcb86 100644 (file)
--- a/src/compiler/spirv/spirv_to_nir.c
+++ b/src/compiler/spirv/spirv_to_nir.c
@@ -1394,8 +1394,11 @@ vtn_handle_function_call(struct vtn_builder *b, SpvOp opcode,
                          const uint32_t *w, unsigned count)
 {
    struct vtn_type *res_type = vtn_value(b, w[1], vtn_value_type_type)->type;
-   struct nir_function *callee =
-      vtn_value(b, w[3], vtn_value_type_function)->func->impl->function;
+   struct vtn_function *vtn_callee =
+      vtn_value(b, w[3], vtn_value_type_function)->func;
+   struct nir_function *callee = vtn_callee->impl->function;
+
+   vtn_callee->referenced = true;
 
    nir_call_instr *call = nir_call_instr_create(b->nb.shader, callee);
    for (unsigned i = 0; i < call->num_params; i++) {
@@ -3366,12 +3369,22 @@ spirv_to_nir(const uint32_t *words, size_t word_count,
 
    vtn_build_cfg(b, words, word_end);
 
-   foreach_list_typed(struct vtn_function, func, node, &b->functions) {
-      b->const_table = _mesa_hash_table_create(b, _mesa_hash_pointer,
-                                               _mesa_key_pointer_equal);
-
-      vtn_function_emit(b, func, vtn_handle_body_instruction);
-   }
+   assert(b->entry_point->value_type == vtn_value_type_function);
+   b->entry_point->func->referenced = true;
+
+   bool progress;
+   do {
+      progress = false;
+      foreach_list_typed(struct vtn_function, func, node, &b->functions) {
+         if (func->referenced && !func->emitted) {
+            b->const_table = _mesa_hash_table_create(b, _mesa_hash_pointer,
+                                                     _mesa_key_pointer_equal);
+
+            vtn_function_emit(b, func, vtn_handle_body_instruction);
+            progress = true;
+         }
+      }
+   } while (progress);
 
    assert(b->entry_point->value_type == vtn_value_type_function);
    nir_function *entry_point = b->entry_point->func->impl->function;

diff --git a/src/compiler/spirv/vtn_cfg.c b/src/compiler/spirv/vtn_cfg.c
index 13f022177100cc4e43c6f11c21054c75e04e01b1..70bbccb7cddd23e7e9ca694d7f2c44ef14fb30d5 100644 (file)
--- a/src/compiler/spirv/vtn_cfg.c
+++ b/src/compiler/spirv/vtn_cfg.c
@@ -783,4 +783,6 @@ vtn_function_emit(struct vtn_builder *b, struct vtn_function *func,
     */
    if (b->has_loop_continue)
       nir_repair_ssa_impl(func->impl);
+
+   func->emitted = true;
 }

diff --git a/src/compiler/spirv/vtn_private.h b/src/compiler/spirv/vtn_private.h
index 173a7b3d7c7f98180d059f96a117d0eed6f5c1c6..751f5011b7d48bf76214d96a4ed89d1379f4504e 100644 (file)
--- a/src/compiler/spirv/vtn_private.h
+++ b/src/compiler/spirv/vtn_private.h
@@ -159,6 +159,9 @@ struct vtn_block {
 struct vtn_function {
    struct exec_node node;
 
+   bool referenced;
+   bool emitted;
+
    nir_function_impl *impl;
    struct vtn_block *start_block;