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Message-ID: <516EE108.2030501@redhat.com>
Date: Wed, 17 Apr 2013 17:51:00 -0000
From: "Carlos O'Donell" <carlos@redhat.com>
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To: Will Newton <will.newton@linaro.org>
CC: libc-ports@sourceware.org, patches@linaro.org
Subject: Re: [PATCH v2] ARM: Add Cortex-A15 optimized NEON and VFP memcpy routines, with IFUNC.
References: <516D18F0.4060009@linaro.org>
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On 04/16/2013 02:25 AM, Will Newton wrote:
> +size_t
> +__libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
> +			size_t max)
> +{
> +  size_t i = 0;
> +  int hwcap;
> +
> +  hwcap = GLRO(dl_hwcap);
> +
> +  IFUNC_IMPL (i, name, memcpy,
> +	      IFUNC_IMPL_ADD (array, i, memcpy, hwcap & HWCAP_ARM_NEON,
> +			      __memcpy_neon)
> +	      IFUNC_IMPL_ADD (array, i, memcpy, hwcap & HWCAP_ARM_VFPv3,
> +			      __memcpy_vfp)
> +	      IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_arm));
> +
> +  return i;
> +}

If unaligned access is a requirement why not check for it here?

While unaligned access is virtually free on ARMv6 or higher it
is still possible for the U-bit to be disabled and for this to
crash on such systems.

Cheers,
Carlos.