vtn: plumb through OpEntryPoint

mark nir_functions as entrypoints according to the source.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Konstantin Seurer <konstantin.seurer@gmail.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Mary Guillemard <mary.guillemard@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32382>

src/compiler/spirv/spirv_to_nir.c

@@ -4869,6 +4869,7 @@ vtn_handle_entry_point(struct vtn_builder *b, const uint32_t *w,
    /* Let this be a name label regardless */
    unsigned name_words;
    entry_point->name = vtn_string_literal(b, &w[3], count - 3, &name_words);
+   entry_point->is_entrypoint = true;
 
    gl_shader_stage stage = vtn_stage_for_execution_model(w[1]);
    vtn_fail_if(stage == MESA_SHADER_NONE,

src/compiler/spirv/vtn_cfg.c

@@ -280,6 +280,17 @@ vtn_cfg_handle_prepass_instruction(struct vtn_builder *b, SpvOp opcode,
       func->dont_inline = b->func->control & SpvFunctionControlDontInlineMask;
       func->is_exported = b->func->linkage == SpvLinkageTypeExport;
 
+      /* This is a bit subtle: if we are compiling a non-library, we will have
+       * exactly one entrypoint. But in library mode, we can have 0, 1, or even
+       * multiple entrypoints. This is OK.
+       *
+       * So, we set is_entrypoint for libraries here (plumbing OpEntryPoint),
+       * but set is_entrypoint elsewhere for graphics shaders.
+       */
+      if (b->options->create_library) {
+         func->is_entrypoint = val->is_entrypoint;
+      }
+
       func->num_params = num_params;
       func->params = rzalloc_array(b->shader, nir_parameter, num_params);
 

src/compiler/spirv/vtn_private.h

@@ -569,6 +569,9 @@ struct vtn_value {
    /* Valid when all the members of the value are undef. */
    bool is_undef_constant:1;
 
+   /* Marked as OpEntryPoint */
+   bool is_entrypoint:1;
+
    const char *name;
    struct vtn_decoration *decoration;
    struct vtn_type *type;