nir: add subroutine fields to nir_function

Acked-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28538>

src/compiler/glsl/glsl_to_nir.cpp

@@ -672,6 +672,14 @@ nir_visitor::create_function(ir_function_signature *ir)
    }
    assert(np == func->num_params);
 
+   func->is_subroutine = ir->function()->is_subroutine;
+   func->num_subroutine_types = ir->function()->num_subroutine_types;
+   func->subroutine_index = ir->function()->subroutine_index;
+   func->subroutine_types =
+      ralloc_array(func, const struct glsl_type *, func->num_subroutine_types);
+   for (int i = 0; i < func->num_subroutine_types; i++)
+     func->subroutine_types[i] = ir->function()->subroutine_types[i];
+
    _mesa_hash_table_insert(this->overload_table, ir, func);
 }
 

src/compiler/nir/nir.c

@@ -502,6 +502,10 @@ nir_function_create(nir_shader *shader, const char *name)
    func->is_preamble = false;
    func->dont_inline = false;
    func->should_inline = false;
+   func->is_subroutine = false;
+   func->subroutine_index = 0;
+   func->num_subroutine_types = 0;
+   func->subroutine_types = NULL;
 
    /* Only meaningful for shader libraries, so don't export by default. */
    func->is_exported = false;

src/compiler/nir/nir.h

@@ -3525,6 +3525,23 @@ typedef struct nir_function {
    /* from SPIR-V function control */
    bool should_inline;
    bool dont_inline; /* from SPIR-V */
+
+   /**
+    * Is this function a subroutine type declaration
+    * e.g. subroutine void type1(float arg1);
+    */
+   bool is_subroutine;
+
+   /**
+    * Is this function associated to a subroutine type
+    * e.g. subroutine (type1, type2) function_name { function_body };
+    * would have num_subroutine_types 2,
+    * and pointers to the type1 and type2 types.
+    */
+   int num_subroutine_types;
+   const struct glsl_type **subroutine_types;
+
+   int subroutine_index;
 } nir_function;
 
 typedef enum {

src/compiler/nir/nir_clone.c

@@ -667,6 +667,16 @@ nir_function_clone(nir_shader *ns, const nir_function *fxn)
    nfxn->is_preamble = fxn->is_preamble;
    nfxn->should_inline = fxn->should_inline;
    nfxn->dont_inline = fxn->dont_inline;
+   nfxn->is_subroutine = fxn->is_subroutine;
+   nfxn->num_subroutine_types = fxn->num_subroutine_types;
+   nfxn->subroutine_index = fxn->subroutine_index;
+   if (fxn->num_subroutine_types) {
+      nfxn->subroutine_types = ralloc_array(ns, const struct glsl_type *,
+                                            fxn->num_subroutine_types);
+      for (unsigned i = 0; i < fxn->num_subroutine_types; i++) {
+         nfxn->subroutine_types[i] = fxn->subroutine_types[i];
+      }
+   }
 
    /* At first glance, it looks like we should clone the function_impl here.
     * However, call instructions need to be able to reference at least the

src/compiler/nir/nir_serialize.c

@@ -1897,10 +1897,18 @@ write_function(write_ctx *ctx, const nir_function *fxn)
       flags |= 0x10;
    if (fxn->dont_inline)
       flags |= 0x20;
+   if (fxn->is_subroutine)
+      flags |= 0x40;
    blob_write_uint32(ctx->blob, flags);
    if (fxn->name)
       blob_write_string(ctx->blob, fxn->name);
 
+   blob_write_uint32(ctx->blob, fxn->subroutine_index);
+   blob_write_uint32(ctx->blob, fxn->num_subroutine_types);
+   for (unsigned i = 0; i < fxn->num_subroutine_types; i++) {
+      encode_type_to_blob(ctx->blob, fxn->subroutine_types[i]);
+   }
+
    write_add_object(ctx, fxn);
 
    blob_write_uint32(ctx->blob, fxn->num_params);
@@ -1922,11 +1930,18 @@ static void
 read_function(read_ctx *ctx)
 {
    uint32_t flags = blob_read_uint32(ctx->blob);
+
    bool has_name = flags & 0x4;
    char *name = has_name ? blob_read_string(ctx->blob) : NULL;
 
    nir_function *fxn = nir_function_create(ctx->nir, name);
 
+   fxn->subroutine_index = blob_read_uint32(ctx->blob);
+   fxn->num_subroutine_types = blob_read_uint32(ctx->blob);
+   for (unsigned i = 0; i < fxn->num_subroutine_types; i++) {
+      fxn->subroutine_types[i] = decode_type_from_blob(ctx->blob);
+   }
+
    read_add_object(ctx, fxn);
 
    fxn->num_params = blob_read_uint32(ctx->blob);
@@ -1943,6 +1958,7 @@ read_function(read_ctx *ctx)
       fxn->impl = NIR_SERIALIZE_FUNC_HAS_IMPL;
    fxn->should_inline = flags & 0x10;
    fxn->dont_inline = flags & 0x20;
+   fxn->is_subroutine = flags & 0x40;
 }
 
 static void