10. At least one non-transitory computer-readable storage medium comprising a set of instructions that, in response to being executed on a computing device, cause the computing device to: determine one or more respective suitability metrics for each of one or more candidate partitioning policies for a set of pixel shader inputs for a graphics frame, each candidate partitioning policy comprising one or more rules for partitioning the set of pixel shader inputs for multi-phase pixel shading based on quality sensitivity values for the pixel shader inputs; select a partitioning policy for the set of pixel shader inputs from among the one or more candidate partitioning policies based on the determined suitability metrics; and construct a multi-phase pixel shader for the graphics frame by partitioning the set of pixel shader inputs into multiple classes according to the selected partitioning policy.
10. At least one non-transitory computer-readable storage medium comprising a set of instructions that, in response to being executed on a computing device, cause the computing device to: determine one or more respective suitability metrics for each of one or more candidate partitioning policies for a set of pixel shader inputs for a graphics frame, each candidate partitioning policy comprising one or more rules for partitioning the set of pixel shader inputs for multi-phase pixel shading based on quality sensitivity values for the pixel shader inputs; select a partitioning policy for the set of pixel shader inputs from among the one or more candidate partitioning policies based on the determined suitability metrics; and construct a multi-phase pixel shader for the graphics frame by partitioning the set of pixel shader inputs into multiple classes according to the selected partitioning policy. 16. The at least one non-transitory computer-readable storage medium of claim 10 , comprising instructions that, in response to being executed on the computing device, cause the computing device to partition the set of pixel shader inputs into a coarse-rate class, a standard-rate class, and a fine-rate class based on set of classification parameters defined by the selected partitioning policy.