From: chenxiaolong <chenxiaolong@loongson.cn>
To: Xi Ruoyao <xry111@xry111.site>, gcc-patches@gcc.gnu.org
Cc: i@xen0n.name, xuchenghua@loongson.cn, chenglulu@loongson.cn
Subject: Re: [PATCH v1 4/4] LoongArch: Add tests for Loongson SX floating-point conversion instructions.
Date: Thu, 07 Sep 2023 10:38:30 +0800 [thread overview]
Message-ID: <80c315eab9316df9801b2f82ccb4de44f556c220.camel@loongson.cn> (raw)
In-Reply-To: <1092975a1cdc4f1bd357d5499540faf755b65854.camel@xry111.site>
在 2023-09-06三的 18:56 +0800，Xi Ruoyao写道：
> On Wed, 2023-09-06 at 18:45 +0800, Xiaolong Chen wrote:
> > + *((int*)& __m128_op0[3]) = 0x004200a0;
> > + *((int*)& __m128_op0[2]) = 0x00000000;
> > + *((int*)& __m128_op0[1]) = 0x004200a0;
> > + *((int*)& __m128_op0[0]) = 0x00200001;
>
> These are aliasing rule violation and they will suddenly blow up when
> GCC optimizer starts to optimize more aggressively based on the
> aliasing
> rule.
>
> Try not to use these (you can write a helper function to memcpy()
> into a
> __m128). Or use -fno-strict-alising in dg-options.
>
Okay, thanks for the tip. After carefully reading the gcc manual, a new
addition -fno-strict-aliasing in dg-options is added.
Thanks.
prev parent reply other threads:[~2023-09-07 2:38 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-06 10:45 Xiaolong Chen
2023-09-06 10:56 ` Xi Ruoyao
2023-09-07 2:38 ` chenxiaolong [this message]
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