nir: Introduce a nir_opt_move_comparisons() pass.
This tries to move comparisons (a common source of boolean values)
closer to their first use. For GPUs which use condition codes,
this can eliminate a lot of temporary booleans and comparisons
which reload the condition code register based on a boolean.
V2: (Timothy Arceri)
- fix move comparision for phis so we dont end up with:
vec1 32 ssa_227 = phi block_34: ssa_1, block_38: ssa_240
vec1 32 ssa_235 = feq ssa_227, ssa_1
vec1 32 ssa_230 = phi block_34: ssa_221, block_38: ssa_235
- add nir_op_i2b/nir_op_f2b to the list of comparisons.
V3: (Timothy Arceri)
- tidy up suggested by Jason.
- add inot/fnot to move comparison list
V4: (Jason Ekstrand)
- clean up move_comparison_source
- get rid of the tuple
- rework phi handling
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com> [v1]
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
3 files changed
