From: Paul Brook <paul@codesourcery.com>
To: qemu-devel@nongnu.org
Cc: vandung.tran@vn.panasonic.com
Subject: Re: [Qemu-devel] implementation of Vmul instruction in QEMU that seems to be illogical
Date: Mon, 6 Dec 2010 09:22:19 +0000 [thread overview]
Message-ID: <201012060922.20190.paul@codesourcery.com> (raw)
In-Reply-To: <OF5D22D8AB.C05F4024-ON472577F1.00116A33-472577F1.0012BADE@ma.panasonic.com.sg>
> Logically, implementation of Vmull.s32 and vmul.u32 is just similar to the
> 8 and 16 bit cases. For example:
> case 4: gen_helper_neon_mull_s32(dest, a, b); break;
> case 5: gen_helper_neon_mull_u32(dest, a, b); break;
> I implemented in this way and tested. It is OK. So I can't understand why
> Vmull.s32 and vmul.u32 were implemented like this in QEMU 0.12.5. Please
> explain for me !
I think you're asking the wrong question. Instead ask yourself why should we
add a new helper when we already know how to do 32x32->64 multiplies.
Paul
prev parent reply other threads:[~2010-12-06 9:22 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-06 3:22 [Qemu-devel] implementation of Vmul instruction in QEMU that seems to be illogical vandung.tran
2010-12-06 9:22 ` Paul Brook [this message]
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