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There are no chips/boards implementing the standard P extension as it is nowhere near finalised. The base for the proposed P extension came from Andes who have
by brucehoult 3y ago
There are no chips/boards implementing the standard P extension as it is nowhere near finalised. The base for the proposed P extension came from Andes who have been shipping their custom packed SIMD ISA on their own NDS32 and then RISC-V cores for a number of years.
There are currently no chips or boards implementing RVV 1.0. There seems to be a prospect for a board with a single core 1.6 GHz dual-issue in-order core (C908) implementing RVV 1.0 for $30-$40 perhaps towards the end of the year. https://twitter.com/SipeedIO/status/1654055669774036993 https://twitter.com/SipeedIO/status/1654055669774036993
There have been chips and boards implementing the mid-2019 RVV draft 0.7.1 since the first Allwinner D1 board with single 1.0 GHz 64 bit C906 core in April 2021 (and a lot more since). In the last few months we have seen three new chips implementing this vector ISA:
- Buffalo Lab BL808 with a 480 MHz C906 (plus a couple of 32 bit cores) and 64 MB of PSRAM: Pine64 Ox64, Sipeed M1s
- THead TH1520 with 4x 2.0 GHz OoO C910 cores similar to Arm A72 in e.g. Pi 4: Lichee Pi 4A, Roma laptop (supposedly), other as yet unannounced boards coming soon
- Sophon SG2042 with 64x 2.0 GHz OoO C910 cores, 64 MB L3 cache, 32x PCIe gen 4, four DDR channels. I've been using one of these remotely via ssh. The first retail machine with it, the Milk-V "Pioneer" is available for preorder in China now, reportedly Crowdsupply soon.
RVV 0.7.1 is very similar to 1.0, but there were a few changes in between that make them incompatible (which is expected because draft specs were never expected to be widely implemented .. but here we are). SOME carefully-written code is binary compatible between them e.g. memcpy(), but in general a little usually trivial conversion is necessary.
- camel-cdr 3y agoI've got my hands on an Allwinner D1, is it possible to use intrinsics for rvv 0.7.1? I'd like to already test a few things in my c libraries. Are there any resources other than carefully reading the spec, that documents the differences between 0.7.1 and 1.0?
- brucehoult 3y agoThere was no work on C intrinsics yet when 0.7.1 was the current draft. That started with 0.8, if I recall correctly. I'd rather program directly in assembly language, or in inline asm, than in intrinsics anyway. They are verbose, ugly, hard to write, hard to read, and even hard to modify because things such as the LMUL are baked into every single function name. I don't know of any document that carefully shows the differences. I'd like to create one, if I had someone to pay for my time to do it.
- GeorgeTirebiter 3y agoMinor: Bouffalo Lab BL808