Minutes of 2020/7/3 meeting

Krste Asanovic

Date: 2020/7/03
Task Group: Vector Extension
Chair: Krste Asanovic
Co-Chair: Roger Espasa
Number of Attendees: ~6
Current issues on github: https://github.com/riscv/riscv-v-spec

This call was sparsely attended due to US Independence day holiday.

Issues discussed:

#373 reserve encodings where rs1=0 and .vx and .vi instructions reduce to simpler

Meeting agreed with reserving these encodings, while acknowledging
implementers might treat as non-conforming variants of existing
instructions. Assemblers should check for reserved usages of these

#365 should vsetvli x0, x0, imm that changes vl set vill?

Consensus at meeting was to leave instruction definition as is.

However, we may want to define assembler syntax for different intended
use cases to help precision of warning/error reporting.

#427 unsigned scalar integer in widening instructions 2*SEW ?

It was felt this proposal needed more justification.

#503 Return of cast operations

There was consensus that this resolution of the casting issue seemed
elegant, imposing no burden on implementations that do not internally
reorganize data while supporting wide machines that optimize internal
data placement.