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* [Qemu-arm] ARM: SVE while issue
@ 2018-07-31 13:52 Laurent Desnogues
  2018-07-31 16:36 ` [Qemu-devel] " Richard Henderson
  0 siblings, 1 reply; 3+ messages in thread
From: Laurent Desnogues @ 2018-07-31 13:52 UTC (permalink / raw)
  To: Richard Henderson; +Cc: qemu-arm, qemu-devel@nongnu.org

Hello Richard,

according to SVE specification, whilels/whilele instructions have a
special case where if the second operand is the maximum (un)signed
integer then the result is an all-true predicate.  The current code in
trans_WHILE doesn't seem to capture that requirement.  I'm afraid the
fix won't be as trivial as for the other two bugs I reported :-)

Thanks,

Laurent

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [Qemu-devel] ARM: SVE while issue
  2018-07-31 13:52 [Qemu-arm] ARM: SVE while issue Laurent Desnogues
@ 2018-07-31 16:36 ` Richard Henderson
  2018-08-01  5:53   ` [Qemu-arm] " Laurent Desnogues
  0 siblings, 1 reply; 3+ messages in thread
From: Richard Henderson @ 2018-07-31 16:36 UTC (permalink / raw)
  To: Laurent Desnogues; +Cc: qemu-arm, qemu-devel@nongnu.org

On 07/31/2018 09:52 AM, Laurent Desnogues wrote:
> Hello Richard,
> 
> according to SVE specification, whilels/whilele instructions have a
> special case where if the second operand is the maximum (un)signed
> integer then the result is an all-true predicate.  The current code in
> trans_WHILE doesn't seem to capture that requirement.  I'm afraid the
> fix won't be as trivial as for the other two bugs I reported :-)

Still not too bad.
Testing a fix for my branch now.

Annoying that risu didn't randomly generate this case,
and I totally mis-read the documentation for this.


r~


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [Qemu-arm] ARM: SVE while issue
  2018-07-31 16:36 ` [Qemu-devel] " Richard Henderson
@ 2018-08-01  5:53   ` Laurent Desnogues
  0 siblings, 0 replies; 3+ messages in thread
From: Laurent Desnogues @ 2018-08-01  5:53 UTC (permalink / raw)
  To: Richard Henderson; +Cc: qemu-arm, qemu-devel@nongnu.org

Hello,

On Tue, Jul 31, 2018 at 6:36 PM, Richard Henderson
<richard.henderson@linaro.org> wrote:
> On 07/31/2018 09:52 AM, Laurent Desnogues wrote:
>> Hello Richard,
>>
>> according to SVE specification, whilels/whilele instructions have a
>> special case where if the second operand is the maximum (un)signed
>> integer then the result is an all-true predicate.  The current code in
>> trans_WHILE doesn't seem to capture that requirement.  I'm afraid the
>> fix won't be as trivial as for the other two bugs I reported :-)
>
> Still not too bad.
> Testing a fix for my branch now.

I gave it a look and tested it, it works fine!

Thanks,

Laurent

> Annoying that risu didn't randomly generate this case,
> and I totally mis-read the documentation for this.
>
>
> r~
>

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2018-08-01  5:53 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2018-07-31 13:52 [Qemu-arm] ARM: SVE while issue Laurent Desnogues
2018-07-31 16:36 ` [Qemu-devel] " Richard Henderson
2018-08-01  5:53   ` [Qemu-arm] " Laurent Desnogues

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