fix: avoid workgroupUniformLoad on atomic type for iOS WGSL compatibility#8552
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mvaligursky merged 1 commit intomainfrom Mar 25, 2026
Merged
fix: avoid workgroupUniformLoad on atomic type for iOS WGSL compatibility#8552mvaligursky merged 1 commit intomainfrom
mvaligursky merged 1 commit intomainfrom
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…lity iOS Safari/WebKit strictly enforces that workgroupUniformLoad requires a concrete plain type, rejecting atomic<u32>. Other platforms are lenient. Use a non-atomic workgroup intermediary: thread 0 copies the atomic value into a plain u32 after a barrier, then all threads read it via workgroupUniformLoad on the plain variable. Made-with: Cursor
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iOS Safari/WebKit's WGSL compiler strictly enforces that
workgroupUniformLoadrequires a concrete plain type, rejectingatomic<u32>with the error'atomic<u32>' cannot be used as the type of a 'let'. Other platforms (macOS, Windows, Android) are more lenient and accept this.Changes:
var<workgroup> doneCountShared: u32intermediary variable in both compute rasterize shadersatomicAddcalls are complete, thread 0 copies the atomic value into the plain variable viaatomicLoadworkgroupUniformLoadon the plainu32, which satisfies both iOS (plain type requirement) and the WGSL uniformity analysis (uniform return value)compute-gsplat-tile-rasterizeandcompute-gsplat-local-rasterize