This commits add the WaveIsFirstLane() hlsl intrinsinc. This intrinsic
uses the convergence intrinsincs for the SPIR-V backend. On the DXIL
side, I'm not sure what the strategy is for convergence, so I
implemented that like in DXC: a normal builtin function.
Signed-off-by: Nathan Gauër <brioche@google.com>
The structurizer will require the frontend to emit convergence
intrinsics. Once uses to restructurize the control-flow, those
intrinsics shall be removed, as they cannot be converted to
SPIR-V.
This commit adds a new pass to the SPIR-V backend which strips those
intrinsics.
Those 2 new steps are not limited to Vulkan as OpenCL could
also benefit from not crashing if a convertent operation is in
the IR (even though the frontend doesn't generate such intrinsics).
Signed-off-by: Nathan Gauër <brioche@google.com>
