From: Richard Henderson <rth@twiddle.net>
To: Max Filippov <jcmvbkbc@gmail.com>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 23/26] target-xtensa: implement interrupt option
Date: Tue, 24 May 2011 07:59:21 -0700 [thread overview]
Message-ID: <4DDBC7C9.4060808@twiddle.net> (raw)
In-Reply-To: <BANLkTin3hbbvZ5CjC_b2QVtoN+veOp00yw@mail.gmail.com>
On 05/24/2011 03:28 AM, Max Filippov wrote:
>>> - cycles fed into advance_ccount may (and on real hardware actually
>>> do) depend on executed commands/pipeline/cache hits. Most of this
>>> stuff may be counted at the translation time;
>>
>> Since CCOUNT, as seen by any one thread of execution, on real hw depends
>> on cache hits, interrupts, and other asynchronous stuff, then don't bother
>> trying to account for it on a per-instruction basis. Just define a clock
>> that runs at a given rate and be done. No need to advance it manually.
>
> It means no cycle-accurate emulation. This was one of my goals, maybe
> not closest one. Is it acceptable to have two simulation modes -- fast
> functional and slower cycle-accurate?
Huh. Given that you're not modeling the caches, I don't see how you could
hope for true cycle accuracy. As for whether a mostly-cycle-accurate mode
should be a goal... I'll have to defer to other QEMU maintainers.
r~
next prev parent reply other threads:[~2011-05-24 14:59 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-17 22:32 [Qemu-devel] [PATCH 00/26] target-xtensa: introduce new target architecture Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 01/26] target-xtensa: add target stubs Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 02/26] target-xtensa: add target to the configure script Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 03/26] target-xtensa: implement disas_xtensa_insn Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 04/26] target-xtensa: implement narrow instructions Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 05/26] target-xtensa: implement RT0 group Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 06/26] target-xtensa: add sample board Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 07/26] target-xtensa: implement conditional jumps Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 08/26] target-xtensa: implement JX/RET0/CALLX Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 09/26] target-xtensa: add special and user registers Max Filippov
2011-05-19 20:59 ` Richard Henderson
2011-05-20 7:34 ` Max Filippov
2011-05-20 14:18 ` Richard Henderson
2011-05-17 22:32 ` [Qemu-devel] [PATCH 10/26] target-xtensa: implement RST3 group Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 11/26] target-xtensa: implement shifts (ST1 and RST1 groups) Max Filippov
2011-05-19 21:15 ` Richard Henderson
2011-05-17 22:32 ` [Qemu-devel] [PATCH 12/26] target-xtensa: implement LSAI group Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 13/26] target-xtensa: mark reserved and TBD opcodes Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 14/26] target-xtensa: implement SYNC group Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 15/26] target-xtensa: implement CACHE group Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 16/26] target-xtensa: implement exceptions Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 17/26] target-xtensa: implement RST2 group (32 bit mul/div/rem) Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 18/26] target-xtensa: implement windowed registers Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 19/26] target-xtensa: implement loop option Max Filippov
2011-05-19 21:51 ` Richard Henderson
2011-05-20 7:25 ` Max Filippov
2011-05-20 9:10 ` Max Filippov
2011-05-20 14:14 ` Richard Henderson
2011-05-17 22:32 ` [Qemu-devel] [PATCH 20/26] target-xtensa: implement extended L32R Max Filippov
2011-05-19 22:00 ` Richard Henderson
2011-05-20 7:14 ` Max Filippov
2011-05-20 15:30 ` Richard Henderson
2011-05-17 22:32 ` [Qemu-devel] [PATCH 21/26] target-xtensa: implement unaligned exception option Max Filippov
2011-05-19 22:04 ` Richard Henderson
2011-05-22 12:10 ` Max Filippov
2011-05-22 16:57 ` Richard Henderson
2011-05-22 20:12 ` Max Filippov
2011-05-23 13:51 ` Richard Henderson
2011-05-23 23:20 ` Max Filippov
2011-05-24 14:57 ` Richard Henderson
2011-05-17 22:32 ` [Qemu-devel] [PATCH 22/26] target-xtensa: implement SIMCALL Max Filippov
2011-05-19 22:07 ` Richard Henderson
2011-05-17 22:32 ` [Qemu-devel] [PATCH 23/26] target-xtensa: implement interrupt option Max Filippov
2011-05-20 15:44 ` Richard Henderson
2011-05-20 20:05 ` Max Filippov
2011-05-20 20:49 ` Richard Henderson
2011-05-20 21:30 ` Max Filippov
2011-05-20 22:19 ` Richard Henderson
2011-05-24 10:28 ` Max Filippov
2011-05-24 14:59 ` Richard Henderson [this message]
2011-05-24 15:11 ` Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 24/26] target-xtensa: implement accurate window check Max Filippov
2011-05-20 15:58 ` Richard Henderson
2011-05-20 19:04 ` Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 25/26] target-xtensa: implement CPENABLE and PRID SRs Max Filippov
2011-05-17 22:32 ` [Qemu-devel] [PATCH 26/26] target-xtensa: implement relocatable vectors Max Filippov
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