Disable null export (for kills) when a frontend defines a pixel
shader as not exporting using amdgpu-color-export and
amdgpu-depth-export function attrbutes.
This allows the generation of export free pixel shaders.
Reviewed By: foad
Differential Revision: https://reviews.llvm.org/D105683
Pass no longer handles skips. Pass now removes unnecessary
unconditional branches and lowers early termination branches.
Hence rename to SILateBranchLowering.
Move code to handle returns to epilog from SIPreEmitPeephole
into SILateBranchLowering. This means SIPreEmitPeephole only
contains optional optimisations, and all required transforms
are in SILateBranchLowering.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D98915
Move implementation of kill intrinsics to WQM pass. Add live lane
tracking by updating a stored exec mask when lanes are killed.
Use live lane tracking to enable early termination of shader
at any point in control flow.
Reviewed By: piotr
Differential Revision: https://reviews.llvm.org/D94746
Add pseudo instruction to allow early termination of pixel shader
anywhere based on the value of SCC. The intention is to use this
when a mask of live lanes is updated, e.g. live lanes in WQM pass.
This facilitates early termination of shaders even when EXEC is
incomplete, e.g. in non-uniform control flow.
Reviewed By: foad
Differential Revision: https://reviews.llvm.org/D88777
