Dr. Philipp Tomsich
Dr. Philipp Tomsich is Chief Technologist and Founder of VRULL GmbH, providing strategic R&D for semiconductor companies. He chairs the RISC-V Applications & Tools Committee, serves on the RISC-V Board of Directors, and is Vice-Chair of the Technical Steering Committee, where he champions software ecosystem growth and standards alignment, including efforts to publish RISC-V under ISO.
He instigated the standards-development matrix operations and AI/ML, serving as principal editor of the Integrated Matrix Extension and as the Vice-chair of the Attached Matrix TG.
Session
RISC-V's Zvvm matrix extension stores all tile state in the standard V register file and derives tile geometry algebraically from VLEN, SEW, and a new aspect-ratio field λ. This yields arithmetic intensity that scales with VLEN: a binary compiled at VLEN=256 delivers higher throughput at VLEN=65536 with no recompilation. The same partial-VL mechanism that enables one-column-at-a-time embedded streaming also drives full HPC bulk tiling, while microscaling is integrated via vm-bit opcode aliasing with no new architectural state.
Tile dimensions are not programmer-specified constants — they are consequences of existing parameters. The tile is always square: M = N = VLEN/(SEW×λ), with inner dimension K_eff = λ×W×LMUL. Arithmetic intensity (M/2) grows proportionally with VLEN, and the ratio of intensity to cache-to-VRF bandwidth remains constant — a provable algebraic identity with no equivalent in Arm SME or Intel AMX.
Zvvm's geometry knobs form an intent vocabulary expressed from both sides: software selects LMUL and VL to control K_eff depth and streaming granularity; hardware determines λ and VLEN to shape the tile for its datapath. Setting VL = K_eff with LMUL = 1 gives portable streaming; increasing LMUL or computing multiple C panels trades register pressure for compute intensity — all via the same opcode.
Microscaling (MX) support is integrated by aliasing the vm bit in FP multiply-accumulate opcodes, introducing no new encoding space, registers, or modes.