From: Luke Kenneth Casson Leighton Date: Thu, 26 Apr 2018 09:51:09 +0000 (+0100) Subject: start filling in X-Git-Tag: convert-csv-opcode-to-binary~5483 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=c9613bd8a1946e10a959e9f144377a36c08e1936;p=libreriscv.git start filling in --- diff --git a/isa_conflict_resolution.mdwn b/isa_conflict_resolution.mdwn index 36a29009d..6de6852cc 100644 --- a/isa_conflict_resolution.mdwn +++ b/isa_conflict_resolution.mdwn @@ -217,13 +217,14 @@ take into account the flaws pointed out by trying to use "MISA": * Each custom-defined bit of the MISA-like CSR would (mutually-exclusively) redirect binary encoding(s) to specific encodings * No Extension would *actually* be disabled: its internal state would - be left on (permanently) so that switching could be done inside - inner loops. + be left on (permanently) so that switching of ISA decoding + could be done inside inner loops without adverse impact on + performance. Whilst it was the first "workable" solution it was also noted that the -scheme is quite invasive: it requires an entirely new CSR to be added -to the privileged spec. This does not completely fulfil the "minimum -impact" requirement. +scheme is invasive: it requires an entirely new CSR to be added +to the privileged spec (thus making existing implementations redundant). +This does not completely fulfil the "minimum impact" requirement. Also interesting around the same time an additional discussion was raised that covered the *compiler* side of the same equation. This