ARM-software / astc-encoder

The Arm ASTC Encoder, a compressor for the Adaptive Scalable Texture Compression data format.
https://developer.arm.com/graphics
Apache License 2.0
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Simplify SVE table lookup #494

Closed solidpixel closed 3 months ago

solidpixel commented 3 months ago

The design of the SVE vtbl allows us to simply bitwise OR successive lookups for a multi-lookup table because, unlike x86 shuffles, it's guaranteed that high values outside of the active 32-bit slice return zero.

This has no impact on compression, but gives a small (0.5%) improvement to decompression performance.