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Re: [PATCH, AArch64] Fix for PR61202
- From: James Greenhalgh <james dot greenhalgh at arm dot com>
- To: Carrot Wei <carrot at google dot com>
- Cc: "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>, Marcus Shawcroft <marsha01 at arm dot com>
- Date: Tue, 20 May 2014 07:50:48 +0100
- Subject: Re: [PATCH, AArch64] Fix for PR61202
- Authentication-results: sourceware.org; auth=none
- References: <CAEe8uEA2ObHCT1DPpsAxLr_xTCx0EY5H8Gu=bXZsDPQJmhem0g at mail dot gmail dot com>
On Tue, May 20, 2014 at 07:18:40AM +0100, Carrot Wei wrote:
> Hi
Hi,
> The last operand of instruction sqdmulh can only be low fp registers,
> so we should use constraint "x". But the intrinsic functions use "w".
> This patch fixed the constrains in these intrinsics.
This restriction is only on the _s16 variants of the intrinsics. From the
ARMv8 Architecture Reference Manual:
<Vm> Is the name of the second SIMD&FP source register,
[...]
Restricted to V0-V15 when element size <Ts> is H.
The patch is correct (though I can't approve it) for vqdmulh_n_s16 and
vqdmulhq_n_s16, but the two hunks for vqdmulh_n_s32 and vqdmulhq_n_s32 should
be dropped as they are too restrictive.
Thanks,
James
> 2014-05-19 Guozhi Wei <carrot@google.com>
>
> * config/aarch64/arm_neon.h (vqdmulh_n_s16): Change
> the last operand's constraint.
> (vqdmulh_n_s32): Likewise.
> (vqdmulhq_n_s16): Likewise.
> (vqdmulhq_n_s32): Likewise.