Rosenzweig: Reverse-engineering the Mali G78
Alyssa Rosenzweig goes into the details of the reverse-engineering of the Mali "Valhall" GPU instruction set.

Valhall linearizes Bifrost, removing the Very Long Instruction Word mechanisms of its predecessors. Valhall replaces the compiler’s static scheduling with hardware dynamic scheduling, trading additional control hardware for higher average performance. That means padding with “no operation” instructions is no longer required, which may decrease code size, promising better instruction cache use.

A document describing the instruction set has been released, along with an assembler and disassembler.