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From: Paul Brook <paul@codesourcery.com>
Subject: Re: [Qemu-devel] [PATCH] SPARC target : Fix carry flag update
	inaddxcc and subxc
Date: Mon, 10 Apr 2006 19:13:54 +0100
References: <BAY104-F23360ECDB73F3CB2DDA7D2FFCC0@phx.gbl>
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To: qemu-devel@nongnu.org

On Monday 10 April 2006 19:04, Blue Swirl wrote:
> >Doesn't this condition in addx and the corresponding line in subx need
> >similar
> >treatment?
>
> They don't change the flags.

It certainly look like they do.

In particular if TARGET_SPARC64 we have

    if ((T0 & 0xffffffff) < (src1 & 0xffffffff))
        env->psr |= PSR_CARRY;

But if !TARGET_SPARC64 we have

-    if (T0 < src1)
+    if (T0 < src1 || (has_carry && T0 <= src1))
 	env->psr |= PSR_CARRY;

I'd expect these two to be the same (modulo the explicit truncation in the 
first case).

Paul