Skip to content

Fix SYCL instID[0] corruption when RTC_MAX_INSTANCE_LEVEL_COUNT > 1 #645

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
stefanatwork merged 2 commits into from
Oct 29, 2026
Merged

Fix SYCL instID[0] corruption when RTC_MAX_INSTANCE_LEVEL_COUNT > 1 #645

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
474d919
Fix SYCL instID[0] corruption when RTC_MAX_INSTANCE_LEVEL_COUNT > 1
stefanatwork Oct 27, 2026
b50a132
Merge branch 'master' into fix/sycl-instance-level-count-bug
stefanatwork Oct 29, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
15 changes: 9 additions & 6 deletions kernels/common/instance_stack.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -160,12 +160,15 @@ RTC_FORCEINLINE void copy_UU(const RTCRayQueryContext* context, const unsigned*
#else

unsigned int depth = context->instStackSize;

for (unsigned l = 0; l < depth; ++l)
tgt[l] = src[l];

for (unsigned l = depth; l < RTC_MAX_INSTANCE_LEVEL_COUNT; ++l)
tgt[l] = RTC_INVALID_GEOMETRY_ID;

/* NOTE: Splitting this into two separate loops (one copying the first
* `depth` elements, one filling the remainder with
* RTC_INVALID_GEOMETRY_ID) has been observed to get miscompiled by some
* SYCL/GPU compilers when `depth` is a runtime value, silently reversing
* which elements get the copied value and which get invalidated. Using a
* single fused loop with a per-element select avoids triggering this. */
for (unsigned l = 0; l < RTC_MAX_INSTANCE_LEVEL_COUNT; ++l)
tgt[l] = (l < depth) ? src[l] : RTC_INVALID_GEOMETRY_ID;

#endif
}
Expand Down
Loading