From: Stefan Weil <weil@mail.berlios.de>
To: Andi Kleen <andi@firstfloor.org>
Cc: QEMU Developers <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [PATCH 5/8] tcg: Add interpreter for bytecode
Date: Sun, 18 Sep 2011 07:49:15 +0200 [thread overview]
Message-ID: <4E75865B.5040106@mail.berlios.de> (raw)
In-Reply-To: <m2pqiyebuu.fsf@firstfloor.org>
Am 18.09.2011 06:03, schrieb Andi Kleen:
> Stefan Weil <weil@mail.berlios.de> writes:
>> +
>> + switch (opc) {
>> + case INDEX_op_end:
>> + case INDEX_op_nop:
>> + break;
>
> You could probably get some more speed out of this by using a threaded
> interpreter with gcc's computed goto extension. That's typically
> significantly faster than a plain switch in a loop.
>
> static void *ops[] = {
> &&op1,
> &&op2,
> ...
> };
>
> #define NEXT() goto *ops[*tb_ptr++];
>
> op1:
> ...
> NEXT();
>
> -Andi
Is there really any difference in the generated code?
gcc already uses a jump table internally to handle the
switch cases.
- Stefan
next prev parent reply other threads:[~2011-09-18 5:49 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-17 19:59 [Qemu-devel] [PATCH 0/8] tcg/interpreter: Add TCG + interpreter for bytecode (virtual machine) Stefan Weil
2011-09-17 20:00 ` [Qemu-devel] [PATCH 1/8] tcg: Declare TCG_TARGET_REG_BITS in tcg.h Stefan Weil
2011-09-17 20:00 ` [Qemu-devel] [PATCH 2/8] tcg: Don't declare TCG_TARGET_REG_BITS in tcg-target.h Stefan Weil
2011-09-17 20:00 ` [Qemu-devel] [PATCH 3/8] tcg: Add forward declarations for local functions Stefan Weil
2011-09-17 21:40 ` Peter Maydell
2011-09-17 20:00 ` [Qemu-devel] [PATCH 4/8] tcg: Add some assertions Stefan Weil
2011-09-17 20:00 ` [Qemu-devel] [PATCH 5/8] tcg: Add interpreter for bytecode Stefan Weil
2011-09-18 4:03 ` Andi Kleen
2011-09-18 5:49 ` Stefan Weil [this message]
2011-09-18 7:22 ` Paolo Bonzini
2011-09-18 17:54 ` Avi Kivity
2011-09-19 6:52 ` Andi Kleen
2011-09-19 11:56 ` Avi Kivity
2011-09-19 14:48 ` Andi Kleen
2011-09-18 10:18 ` Blue Swirl
2011-09-19 16:43 ` Richard Henderson
2011-09-19 20:24 ` Stuart Brady
2011-10-16 21:54 ` Stuart Brady
2011-09-17 20:00 ` [Qemu-devel] [PATCH 6/8] tcg: Add bytecode generator for tcg interpreter Stefan Weil
2011-09-18 10:03 ` Blue Swirl
2011-09-19 22:28 ` Stuart Brady
2011-10-01 16:54 ` Andreas Färber
2011-10-01 21:25 ` Stefan Weil
2011-10-09 16:19 ` Andreas Färber
2011-09-17 20:00 ` [Qemu-devel] [PATCH 7/8] tcg: Add tcg interpreter to configure / make Stefan Weil
2011-09-18 9:37 ` Blue Swirl
2011-09-18 10:14 ` Stefan Weil
2011-09-17 20:00 ` [Qemu-devel] [PATCH 8/8] ppc: Support tcg interpreter on ppc hosts Stefan Weil
2011-09-17 21:31 ` Peter Maydell
2011-09-17 21:33 ` Stefan Weil
2011-09-18 10:26 ` [Qemu-devel] [PATCH 0/8] tcg/interpreter: Add TCG + interpreter for bytecode (virtual machine) Blue Swirl
2011-09-18 10:49 ` malc
2011-09-18 12:12 ` Blue Swirl
2011-09-18 12:46 ` malc
2011-09-18 13:00 ` Blue Swirl
2011-09-18 13:13 ` malc
2011-09-18 13:26 ` Blue Swirl
2011-09-25 20:37 ` Stefan Weil
2011-10-01 12:02 ` Blue Swirl
2011-09-18 15:02 ` Mulyadi Santosa
2011-09-18 15:13 ` Stefan Weil
2011-09-18 16:39 ` Mulyadi Santosa
2011-09-18 20:15 ` Stefan Weil
2011-09-19 15:14 ` Mulyadi Santosa
2011-09-19 8:40 ` David Gilbert
2011-09-19 10:20 ` Stefan Hajnoczi
2011-09-19 10:27 ` David Gilbert
2011-09-18 18:02 ` Avi Kivity
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