From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
To: Libre-RISCV General Development <libre-riscv-dev@lists.libre-riscv.org>
Subject: Re: [libre-riscv-dev] extremely busy crowdsupply update started
Date: Fri, 27 Mar 2020 19:20:38 +0000
Message-ID: <CAPweEDzdUCst63B3ZFh6jyqLexdq3SjmUstJ=n9dNY=pMT_HyA@mail.gmail.com> (raw)
In-Reply-To: <20200327173545.2974f6c21ade7d9adfcc9808@platen-software.de>
On Fri, Mar 27, 2020 at 4:35 PM Tobias Platen
<libre-soc@platen-software.de> wrote:
>
> On Fri, 27 Mar 2020 15:49:45 +0000
> Luke Kenneth Casson Leighton <lkcl@lkcl.net> wrote:
>
> I've cloned the repository and now I could write something to fill one or more TODOs in the file 023_2020mar26_decoder_emulator_started.mdwn probably either Coriolis2 experimentation started or POWER ISA decoder and Simulator.
sure - i've added you to the repo so you can git push to it.
> I think I'll work on the POWER ISA decoder and Simulator next.
i had an idea about that, based on this:
http://lists.mailinglist.openpowerfoundation.org/pipermail/openpower-hdl-cores/2020-March/000007.html
my feeling is, we're wasting our time trying to "manually" create both
a processor and also a simulator, from "scratch", when there are
perfectly good, machine-readable expressions (at least for the integer
instructions), like this:
lbz RT,D(RA)
34 RT RA D
0 6 11 16 31
if RA = 0 then b <= 0
else b <= (RA)
EA <= + EXTS(D)
RT <= 56^0 || MEM(EA, 1)
i'm advocating, therefore, that we *literally* parse the PDF spec,
create an "interpreter" for those fragments, then auto-generate code
and HDL from them.
mulhwu RT,RA,RB (Rc=0)
mulhwu. RT,RA,RB (Rc=1)
31 RT RA RB / 11 Rc
0 6 11 16 21 22 31
prod0:63 <- (RA)32:63 x (RB)32:63
RT32:63 <- prod0:31
RT0:31 <- undefined
those really don't look very hard, to turn into code, do they?
FP is a little more challenging because they use "words" to describe
most aspects of the hardware. oh wait! Appendix A p775 v3.0B
contains FP to rounding algorithms, and a few more besides.
i would not be at all surprised if, should we do document-parsing, we
had an entire simulator for the integer V3.0 system in a week, and the
hardware in around 2.
l.
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Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-26 21:03 Luke Kenneth Casson Leighton
2020-03-27 5:49 ` Jacob Lifshay
2020-03-27 8:47 ` Luke Kenneth Casson Leighton
2020-03-27 21:31 ` Jacob Lifshay
2020-03-27 21:36 ` Luke Kenneth Casson Leighton
2020-03-31 4:18 ` Jacob Lifshay
2020-03-27 14:39 ` Immanuel, Yehowshua U
2020-03-27 15:49 ` Luke Kenneth Casson Leighton
2020-03-27 16:35 ` Tobias Platen
2020-03-27 19:20 ` Luke Kenneth Casson Leighton [this message]
2020-03-27 21:29 ` Jacob Lifshay
2020-03-27 21:32 ` Luke Kenneth Casson Leighton
2020-03-28 11:52 ` Luke Kenneth Casson Leighton
2020-03-27 16:56 ` Michael Nolan
2020-03-27 19:21 ` Luke Kenneth Casson Leighton
2020-03-28 8:09 ` Jock Tanner
2020-03-28 10:02 ` Luke Kenneth Casson Leighton
2020-03-28 16:44 ` Jean-Paul Chaput
2020-03-28 17:13 ` Luke Kenneth Casson Leighton
2020-03-31 8:17 ` Jean-Paul Chaput
2020-03-31 9:31 ` Luke Kenneth Casson Leighton
2020-03-31 9:32 ` Luke Kenneth Casson Leighton
2020-03-31 9:38 ` [libre-riscv-dev] pyobjc, gnu objective-c and gnustep Luke Kenneth Casson Leighton
2020-03-31 11:42 ` lkcl .
2020-03-31 14:11 ` Jean-Paul Chaput
2020-03-31 14:30 ` lkcl .
2020-03-31 16:16 ` Jacob Lifshay
2020-03-28 17:14 ` [libre-riscv-dev] extremely busy crowdsupply update started Luke Kenneth Casson Leighton
2020-03-28 23:16 ` Luke Kenneth Casson Leighton
2020-03-29 13:23 ` Jock Tanner
2020-03-29 13:46 ` Luke Kenneth Casson Leighton
2020-03-29 10:46 ` Jock Tanner
2020-03-29 11:22 ` Luke Kenneth Casson Leighton
2020-03-29 16:05 ` Immanuel, Yehowshua U
2020-03-29 16:26 ` Luke Kenneth Casson Leighton
2020-03-28 18:07 ` Michael Nolan
2020-03-28 18:33 ` Luke Kenneth Casson Leighton
2020-03-31 11:17 ` Luke Kenneth Casson Leighton
2020-03-29 3:14 ` Immanuel, Yehowshua U
2020-03-29 3:15 ` Immanuel, Yehowshua U
2020-03-31 11:26 ` Luke Kenneth Casson Leighton
2020-03-31 18:09 ` Luke Kenneth Casson Leighton
2020-03-31 18:14 ` Luke Kenneth Casson Leighton
2020-04-01 1:51 ` [libre-riscv-dev] name change announcement on crowdsupply Jacob Lifshay
2020-04-01 1:52 ` Jacob Lifshay
2020-04-01 10:57 ` Luke Kenneth Casson Leighton
2020-04-01 17:31 ` Jacob Lifshay
2020-04-01 17:44 ` Luke Kenneth Casson Leighton
2020-03-31 18:35 ` [libre-riscv-dev] extremely busy crowdsupply update started Cole Poirier
2020-03-31 23:11 ` Cole Poirier
2020-04-01 10:08 ` Luke Kenneth Casson Leighton
2020-04-01 10:54 ` Luke Kenneth Casson Leighton
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