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From: Nathan Whitehorn <nwhitehorn@freebsd.org>
To: Richard Henderson <rth@twiddle.net>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH] ppc64: fix mtmsr behavior on 64-bit targets
Date: Sat, 04 Jun 2011 14:28:09 -0500	[thread overview]
Message-ID: <4DEA8749.6090902@freebsd.org> (raw)
In-Reply-To: <4DE52823.4000805@twiddle.net>

On 05/31/11 12:40, Richard Henderson wrote:
> On 05/31/2011 07:56 AM, Nathan Whitehorn wrote:
>>   #if defined(TARGET_PPC64)
>> -        if (!ctx->sf_mode) {
>>               TCGv t0 = tcg_temp_new();
>>               TCGv t1 = tcg_temp_new();
> You're removing a scope in which these variables were defined.
> That seems wrong, at minimum.
>

I'll fix that (and resend the patch), thanks. A note on this: it looks 
like a lot of code here incorrectly changes behavior depending on the 
setting of MSR[SF]. While most of them aren't checking the condition the 
wrong way, like here, MSR[SF] actually changes very few aspects of the 
processor's operation. Turning MSR[SF] on or off on a 64-bit CPU 
basically only affects whether it pays attention to the high 32-bits of 
addresses when doing loads, stores, and branches -- 64-bit arithmetic, 
comparisons, registers, etc. are all available whatever the setting of 
MSR[SF].
-Nathan

  reply	other threads:[~2011-06-04 19:28 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-31 14:56 [Qemu-devel] [PATCH] ppc64: fix mtmsr behavior on 64-bit targets Nathan Whitehorn
2011-05-31 16:48 ` Alexander Graf
2011-05-31 17:40 ` Richard Henderson
2011-06-04 19:28   ` Nathan Whitehorn [this message]
2011-06-05  9:00     ` Alexander Graf
2011-06-05 13:33       ` Nathan Whitehorn
2011-06-05 13:36         ` Nathan Whitehorn
2011-06-05 13:45         ` Alexander Graf
2011-06-12 15:49           ` [Qemu-devel] [PATCH2] " Nathan Whitehorn
2011-06-13 10:20             ` Alexander Graf
2011-06-13 12:52               ` Nathan Whitehorn
2011-06-13 13:17                 ` Alexander Graf

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