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, 9 insertions, 9 deletions

diff --git a/intern/cycles/kernel/kernel_path_volume.h b/intern/cycles/kernel/kernel_path_volume.h
index 6b62005d19a..db10629ee9f 100644
--- a/intern/cycles/kernel/kernel_path_volume.h
+++ b/intern/cycles/kernel/kernel_path_volume.h
@@ -27,8 +27,8 @@ ccl_device_inline void kernel_path_volume_connect_light(KernelGlobals *kg,
 {
 #  ifdef __EMISSION__
   /* 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;
 
@@ -42,7 +42,7 @@ ccl_device_inline void kernel_path_volume_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(
@@ -71,9 +71,9 @@ ccl_device_noinline_cpu bool kernel_path_volume_bounce(KernelGlobals *kg,
 {
   /* sample phase function */
   float phase_pdf;
-  BsdfEval phase_eval;
-  float3 phase_omega_in;
-  differential3 phase_domega_in;
+  BsdfEval phase_eval ccl_optional_struct_init;
+  float3 phase_omega_in ccl_optional_struct_init;
+  differential3 phase_domega_in ccl_optional_struct_init;
   float phase_u, phase_v;
   path_state_rng_2D(kg, state, PRNG_BSDF_U, &phase_u, &phase_v);
   int label;
@@ -139,7 +139,7 @@ ccl_device void kernel_branched_path_volume_connect_light(KernelGlobals *kg,
                                                           const VolumeSegment *segment)
 {
 #    ifdef __EMISSION__
-  BsdfEval L_light;
+  BsdfEval L_light ccl_optional_struct_init;
 
   int num_lights = 1;
   if (sample_all_lights) {
@@ -181,7 +181,7 @@ ccl_device void kernel_branched_path_volume_connect_light(KernelGlobals *kg,
     float num_samples_inv = 1.0f / (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;
@@ -201,7 +201,7 @@ ccl_device void kernel_branched_path_volume_connect_light(KernelGlobals *kg,
           light_u = 0.5f * light_u;
         }
 
-        LightSample ls;
+        LightSample ls ccl_optional_struct_init;
         const int lamp = is_lamp ? i : -1;
         light_sample(kg, lamp, light_u, light_v, sd->time, ray->P, state->bounce, &ls);