[llvm-dev] [RFC] Upstream development of support for yet-to-be-ratified RISC-V extensions

[Evandro Menezes via llvm-dev]

> On Jan 21, 2020, at 7:00, Alex Bradbury via llvm-dev <llvm-dev at lists.llvm.org> wrote:
> 
> ...
> 
> So based on feedback so far, I'd like to narrow the field to:
> 
> Option 1)
> * Unratified extensions are not available through the ISA naming
> string and are enabled via `-riscv-experimental-foo` or similar
> * A warning is always emitted when enabling experimental extensions
> * Support is always compiled in, and the flags aren't ifdeffed out
> 
> Option 2)
> * Unratified extensions can be enabled by passing a flag like
> -riscv-enable-experimental-extensions and additionally putting the
> extension name and version number in the ISA naming string (version
> number is always required, and we will only accept the 'current'
> version number).
> * A warning is always emitted when enabling experimental extensions
> * Support is always compiled in, and the flags aren't ifdeffed out

Option 2 seems more intentional to me, so it gets my vote.

Thank you, Alex.

__ 
Evandro Menezes ◊ SiFive ◊ Austin, TX