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From: Paolo Bonzini <pbonzini@redhat.com>
To: Peter Maydell <peter.maydell@linaro.org>,
	Richard Henderson <richard.henderson@linaro.org>
Cc: qemu-devel@nongnu.org
Subject: Re: [PATCH] meson: Adjust check for __int128_t
Date: Wed, 24 May 2023 14:37:02 +0200	[thread overview]
Message-ID: <3fbe7180-034f-c60f-1479-f8a9e6473eb7@redhat.com> (raw)
In-Reply-To: <CAFEAcA89YToWdvwprxQgaMBpp4KVFqj8asXpBBcikg8zseSv0w@mail.gmail.com>

On 5/24/23 12:30, Peter Maydell wrote:
> On Tue, 23 May 2023 at 23:39, Richard Henderson
> <richard.henderson@linaro.org> wrote:
>>
>> Remove the signed * signed check, leaving the signed * unsigned check.
>> This link test runs foul of -fsanitize=undefined, where clang-11 has
>> an undefined reference to __muloti4 to check for signed overflow.
> 
> If you can't do a signed * signed multiply then that sounds
> to me like "int128_t doesn't work on this compiler". We
> specifically added this check to catch "some clang with
> -fsanitize=undefined don't actually correctly compile
> int128_t * int128_t" in commit 464e3671f9.

Oops, missed this reply before queuing (and will leave the patch aside 
until the discussion is over).

As long as -fsanitize=undefined is properly covered by CI and we don't 
need int128_t * int128_t multiplication, removing the test is ok IMO, 
though perhaps it should have a comment about why it's avoided.

Paolo



  reply	other threads:[~2023-05-24 12:37 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-23 22:38 [PATCH] meson: Adjust check for __int128_t Richard Henderson
2023-05-24 10:30 ` Peter Maydell
2023-05-24 12:37   ` Paolo Bonzini [this message]
2023-05-24 12:31 ` Paolo Bonzini
2023-05-24 12:33   ` Peter Maydell
2023-05-24 12:41     ` Paolo Bonzini

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