Cycles: code to optionally zero initialize some structs in the kernel

This will be used by Optix to help the compiler figure out scoping. It is not
used by other devices currently, but worth testing if it helps there too.

Ref D5363

1 files changed, 12 insertions, 12 deletions

diff --git a/intern/cycles/kernel/kernel_path_surface.h b/intern/cycles/kernel/kernel_path_surface.h
index d299106ea96..a32690d51eb 100644
--- a/intern/cycles/kernel/kernel_path_surface.h
+++ b/intern/cycles/kernel/kernel_path_surface.h
@@ -32,7 +32,7 @@ ccl_device_noinline_cpu void kernel_branched_path_surface_connect_light(
 {
 #  ifdef __EMISSION__
   /* sample illumination from lights to find path contribution */
-  BsdfEval L_light;
+  BsdfEval L_light ccl_optional_struct_init;
 
   int num_lights = 0;
   if (kernel_data.integrator.use_direct_light) {
@@ -79,7 +79,7 @@ ccl_device_noinline_cpu void kernel_branched_path_surface_connect_light(
     float num_samples_inv = num_samples_adjust / (num_samples * num_all_lights);
 
     for (int j = 0; j < num_samples; j++) {
-      Ray light_ray;
+      Ray light_ray ccl_optional_struct_init;
       light_ray.t = 0.0f; /* reset ray */
 #    ifdef __OBJECT_MOTION__
       light_ray.time = sd->time;
@@ -98,7 +98,7 @@ ccl_device_noinline_cpu void kernel_branched_path_surface_connect_light(
           light_u = 0.5f * light_u;
         }
 
-        LightSample ls;
+        LightSample ls ccl_optional_struct_init;
         const int lamp = is_lamp ? i : -1;
         if (light_sample(kg, lamp, light_u, light_v, sd->time, sd->P, state->bounce, &ls)) {
           /* The sampling probability returned by lamp_light_sample assumes that all lights were
@@ -147,9 +147,9 @@ ccl_device bool kernel_branched_path_surface_bounce(KernelGlobals *kg,
 {
   /* sample BSDF */
   float bsdf_pdf;
-  BsdfEval bsdf_eval;
-  float3 bsdf_omega_in;
-  differential3 bsdf_domega_in;
+  BsdfEval bsdf_eval ccl_optional_struct_init;
+  float3 bsdf_omega_in ccl_optional_struct_init;
+  differential3 bsdf_domega_in ccl_optional_struct_init;
   float bsdf_u, bsdf_v;
   path_branched_rng_2D(
       kg, state->rng_hash, state, sample, num_samples, PRNG_BSDF_U, &bsdf_u, &bsdf_v);
@@ -220,8 +220,8 @@ ccl_device_inline void kernel_path_surface_connect_light(KernelGlobals *kg,
   kernel_branched_path_surface_connect_light(kg, sd, emission_sd, state, throughput, 1.0f, L, all);
 #  else
   /* sample illumination from lights to find path contribution */
-  Ray light_ray;
-  BsdfEval L_light;
+  Ray light_ray ccl_optional_struct_init;
+  BsdfEval L_light ccl_optional_struct_init;
   bool is_lamp = false;
   bool has_emission = false;
 
@@ -234,7 +234,7 @@ ccl_device_inline void kernel_path_surface_connect_light(KernelGlobals *kg,
     float light_u, light_v;
     path_state_rng_2D(kg, state, PRNG_LIGHT_U, &light_u, &light_v);
 
-    LightSample ls;
+    LightSample ls ccl_optional_struct_init;
     if (light_sample(kg, -1, light_u, light_v, sd->time, sd->P, state->bounce, &ls)) {
       float terminate = path_state_rng_light_termination(kg, state);
       has_emission = direct_emission(
@@ -274,9 +274,9 @@ ccl_device bool kernel_path_surface_bounce(KernelGlobals *kg,
   if (sd->flag & SD_BSDF) {
     /* sample BSDF */
     float bsdf_pdf;
-    BsdfEval bsdf_eval;
-    float3 bsdf_omega_in;
-    differential3 bsdf_domega_in;
+    BsdfEval bsdf_eval ccl_optional_struct_init;
+    float3 bsdf_omega_in ccl_optional_struct_init;
+    differential3 bsdf_domega_in ccl_optional_struct_init;
     float bsdf_u, bsdf_v;
     path_state_rng_2D(kg, state, PRNG_BSDF_U, &bsdf_u, &bsdf_v);
     int label;