nir: Add a concept of constant data associated with a shader

This commit adds a concept to NIR of having a blob of constant data
associated with a shader.  Instead of being a UBO or uniform that can be
manipulated by the client, this constant data considered part of the
shader and remains constant across all invocations of the given shader
until the end of time.  To access this constant data from the shader, we
add a new load_constant intrinsic.  The intention is that drivers will
eventually lower load_constant intrinsics to load_ubo, load_uniform, or
something similar.  Constant data will be used by the optimization pass
in the next commit but this concept may also be useful for OpenCL.

v2 (Jason Ekstrand):
 - Rename num_constants to constant_data_size (anholt)

Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index e35bef612df8842fa86b88a433aa117850a30598..cc5f88d6f54138013abf6ee01f003827275fd267 100644 (file)
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -2067,6 +2067,14 @@ typedef struct nir_shader {
     * access plus one
     */
    unsigned num_inputs, num_uniforms, num_outputs, num_shared;
+
+   /** Constant data associated with this shader.
+    *
+    * Constant data is loaded through load_constant intrinsics.  See also
+    * nir_opt_large_constants.
+    */
+   void *constant_data;
+   unsigned constant_data_size;
 } nir_shader;
 
 static inline nir_function_impl *

diff --git a/src/compiler/nir/nir_clone.c b/src/compiler/nir/nir_clone.c
index 23bb17eeba3821a6f8acf6d1ec24a8d80b25d6d1..989c5051a54bd3faa8d8671ea0a7c066489505d1 100644 (file)
--- a/src/compiler/nir/nir_clone.c
+++ b/src/compiler/nir/nir_clone.c
@@ -734,6 +734,12 @@ nir_shader_clone(void *mem_ctx, const nir_shader *s)
    ns->num_outputs = s->num_outputs;
    ns->num_shared = s->num_shared;
 
+   ns->constant_data_size = s->constant_data_size;
+   if (s->constant_data_size > 0) {
+      ns->constant_data = ralloc_size(ns, s->constant_data_size);
+      memcpy(ns->constant_data, s->constant_data, s->constant_data_size);
+   }
+
    free_clone_state(&state);
 
    return ns;

diff --git a/src/compiler/nir/nir_intrinsics.py b/src/compiler/nir/nir_intrinsics.py
index d9d0bbdfccfcbada376e2bcaf3fcdf5ce29f2e8d..44a5b76beb6d6e73623bc4a83183549b24466659 100644 (file)
--- a/src/compiler/nir/nir_intrinsics.py
+++ b/src/compiler/nir/nir_intrinsics.py
@@ -532,6 +532,8 @@ load("per_vertex_output", 2, [BASE, COMPONENT], [CAN_ELIMINATE])
 load("shared", 1, [BASE], [CAN_ELIMINATE])
 # src[] = { offset }. const_index[] = { base, range }
 load("push_constant", 1, [BASE, RANGE], [CAN_ELIMINATE, CAN_REORDER])
+# src[] = { offset }. const_index[] = { base, range }
+load("constant", 1, [BASE, RANGE], [CAN_ELIMINATE, CAN_REORDER])
 
 # Stores work the same way as loads, except now the first source is the value
 # to store and the second (and possibly third) source specify where to store

diff --git a/src/compiler/nir/nir_serialize.c b/src/compiler/nir/nir_serialize.c
index cc4bf23aa0f2b2180b23f35a0439c6b75d76c1af..6a30738c2d764751f1fbb6a0648a27df922636d2 100644 (file)
--- a/src/compiler/nir/nir_serialize.c
+++ b/src/compiler/nir/nir_serialize.c
@@ -1116,6 +1116,10 @@ nir_serialize(struct blob *blob, const nir_shader *nir)
       write_function_impl(&ctx, fxn->impl);
    }
 
+   blob_write_uint32(blob, nir->constant_data_size);
+   if (nir->constant_data_size > 0)
+      blob_write_bytes(blob, nir->constant_data, nir->constant_data_size);
+
    *(uintptr_t *)(blob->data + idx_size_offset) = ctx.next_idx;
 
    _mesa_hash_table_destroy(ctx.remap_table, NULL);
@@ -1169,6 +1173,14 @@ nir_deserialize(void *mem_ctx,
    nir_foreach_function(fxn, ctx.nir)
       fxn->impl = read_function_impl(&ctx, fxn);
 
+   ctx.nir->constant_data_size = blob_read_uint32(blob);
+   if (ctx.nir->constant_data_size > 0) {
+      ctx.nir->constant_data =
+         ralloc_size(ctx.nir, ctx.nir->constant_data_size);
+      blob_copy_bytes(blob, ctx.nir->constant_data,
+                      ctx.nir->constant_data_size);
+   }
+
    free(ctx.idx_table);
 
    return ctx.nir;

diff --git a/src/compiler/nir/nir_sweep.c b/src/compiler/nir/nir_sweep.c
index b14bf139c1bca52f47eb950159771913638b17d2..aab641388dbcf40df906533e2749870da5b4aefe 100644 (file)
--- a/src/compiler/nir/nir_sweep.c
+++ b/src/compiler/nir/nir_sweep.c
@@ -167,6 +167,8 @@ nir_sweep(nir_shader *nir)
       sweep_function(nir, func);
    }
 
+   ralloc_steal(nir, nir->constant_data);
+
    /* Free everything we didn't steal back. */
    ralloc_free(rubbish);
 }