[Mesa-dev] [PATCH v2 25/32] i965: add cache fallback support using serialized nir

[Jordan Justen]

If the i965 gen program cannot be loaded from the cache, then we
fallback to using a serialized nir program.

This is based on "i965: add cache fallback support" by Timothy Arceri
<timothy.arceri at collabora.com>. Tim's version was written to fallback
to compiling from source, and therefore had to be much more complex.
After Connor and Jason implemented nir serialization, I was able to
rewrite and greatly simplify this patch.

Signed-off-by: Jordan Justen <jordan.l.justen at intel.com>
---
 src/mesa/drivers/dri/i965/brw_disk_cache.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/mesa/drivers/dri/i965/brw_disk_cache.c b/src/mesa/drivers/dri/i965/brw_disk_cache.c
index d89df846d5..790fad6925 100644
--- a/src/mesa/drivers/dri/i965/brw_disk_cache.c
+++ b/src/mesa/drivers/dri/i965/brw_disk_cache.c
@@ -24,6 +24,7 @@
 #include "compiler/blob.h"
 #include "compiler/glsl/ir_uniform.h"
 #include "compiler/glsl/shader_cache.h"
+#include "compiler/nir/nir_serialize.h"
 #include "main/mtypes.h"
 #include "util/disk_cache.h"
 #include "util/macros.h"
@@ -79,6 +80,27 @@ gen_shader_sha1(struct brw_context *brw, struct gl_program *prog,
    _mesa_sha1_compute(manifest, strlen(manifest), out_sha1);
 }
 
+static void
+fallback_to_full_recompile(struct brw_context *brw, struct gl_program *prog,
+                           gl_shader_stage stage)
+{
+   prog->program_written_to_cache = false;
+   if (brw->ctx._Shader->Flags & GLSL_CACHE_INFO) {
+      fprintf(stderr, "falling back to nir %s.\n",
+              _mesa_shader_stage_to_abbrev(prog->info.stage));
+   }
+
+   if (!prog->nir) {
+      assert(prog->serialized_nir && prog->serialized_nir_size > 0);
+      const struct nir_shader_compiler_options *options =
+         brw->ctx.Const.ShaderCompilerOptions[stage].NirOptions;
+      struct blob_reader reader;
+      blob_reader_init(&reader, prog->serialized_nir,
+                       prog->serialized_nir_size);
+      prog->nir = nir_deserialize(NULL, options, &reader);
+   }
+}
+
 static void
 read_program_data(struct gl_program *glprog, struct blob_reader *binary,
                   struct brw_stage_prog_data *prog_data,
@@ -298,6 +320,9 @@ brw_disk_cache_upload_program(struct brw_context *brw, gl_shader_stage stage)
        prog->sh.LinkedTransformFeedback->api_enabled)
       return false;
 
+   if (brw->ctx._Shader->Flags & GLSL_CACHE_FALLBACK)
+      goto FAIL;
+
    if (prog->sh.data->LinkStatus != linking_skipped)
       goto FAIL;
 
@@ -311,7 +336,7 @@ brw_disk_cache_upload_program(struct brw_context *brw, gl_shader_stage stage)
    return true;
 
 FAIL:
-   /*FIXME: Fall back and compile from source here. */
+   fallback_to_full_recompile(brw, prog, stage);
    return false;
 }
 
-- 
2.15.0.rc0