SPIR-V Built-In
SubgroupLtMask
Mask of shader invocations in a subgroup with a lower subgroup local invocation ID
SubgroupLtMask
Decorating a variable with the SubgroupLtMask builtin decoration will
make that variable contain the subgroup mask of the current subgroup
invocation.
The bits corresponding to the invocations less than
SubgroupLocalInvocationId are set in the variable decorated with
SubgroupLtMask.
All other bits are set to zero.
SubgroupLtMaskKHR is an alias of SubgroupLtMask.
Valid Usage
VUID-SubgroupLtMask-SubgroupLtMask-04378
The variable decorated with SubgroupLtMask must be declared using
the Input Storage Class
VUID-SubgroupLtMask-SubgroupLtMask-04379
The variable decorated with SubgroupLtMask must be declared as a
four-component vector of 32-bit integer values