search

riscv / riscv-profiles

RISC-V Architecture Profiles
Creative Commons Attribution 4.0 International
116 stars 33 forks source link

Missing requirements on VLEN and ELEN in RVA23U64 #178

Closed xypron closed 3 months ago

xypron commented 3 months ago

The RVA23U64 profile requires the V extension but does not provide minimum values for VLEN (bits in a single vector register) and ELEN (maximum size in bits of a vector element . The only requirement in the Unprivileged Architecture specification, 2024-04-11 is 8 <= ELEN <= VLEN. This makes writing reusable code harder than necessary.

We should require:

xypron commented 3 months ago

31.18.3. V: Vector Extension for Application Processors

has "The V vector extension depends upon the Zvl128b and Zve64d extensions.".