subgroup_uniformity

Check navigator.gpu?.wgslLanguageFeatures?.has('subgroup_uniformity') before choosing a shader that uses this language feature. It is available automatically when supported; requires subgroup_uniformity; documents the dependency and rejects the shader on unsupported implementations. This language token is not a requiredFeatures entry for requestDevice(); any additional device requirements are described below.

Uniformity analysis checks that invocations reach collective operations in valid control flow. This extension lets the analysis recognize control flow shared by all invocations in a subgroup, even when other subgroups take a different path. It applies to subgroup and quad built-ins.

Algorithms can use this when different subgroups handle different tasks but each participating subgroup still executes its collective operation together. It can avoid forcing unrelated subgroups down the same branch merely to satisfy a broader uniformity requirement.

Enable the device’s subgroups feature and include enable subgroups; in WGSL as well. This extension does not permit arbitrary per-lane divergence around collectives or relax the requirements of workgroup-wide barriers. For a portable fallback, restructure control flow so the collective is reached uniformly at the broader required scope and select or mask values around it.