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From: Andi Kleen <andi@firstfloor.org>
References: <4E74FC29.1050003@mail.berlios.de>
	<1316289634-18786-5-git-send-email-weil@mail.berlios.de>
Date: Sat, 17 Sep 2011 21:03:05 -0700
In-Reply-To: <1316289634-18786-5-git-send-email-weil@mail.berlios.de> (Stefan
	Weil's message of "Sat, 17 Sep 2011 22:00:31 +0200")
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Subject: Re: [Qemu-devel] [PATCH 5/8] tcg: Add interpreter for bytecode
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To: Stefan Weil <weil@mail.berlios.de>
Cc: QEMU Developers <qemu-devel@nongnu.org>

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

-- 
ak@linux.intel.com -- Speaking for myself only