Re: [PATCH v5] arch/arm: optimization for memcpy on AArch64

[Thomas Monjalon <thomas@monjalon.net>]

Hi,

All the code is using ARM64, but the title suggests AArch64.
What is the difference between AArch64 and ARM64 (and ARMv8)?

04/01/2018 11:20, Herbert Guan:
> +/**************************************
> + * Beginning of customization section
> + **************************************/
> +#define RTE_ARM64_MEMCPY_ALIGN_MASK 0x0F
> +#ifndef RTE_ARCH_ARM64_MEMCPY_STRICT_ALIGN
> +/* Only src unalignment will be treaed as unaligned copy */

typo: treaed

> +#define RTE_ARM64_MEMCPY_IS_UNALIGNED_COPY(dst, src) \
> +	((uintptr_t)(dst) & RTE_ARM64_MEMCPY_ALIGN_MASK)
> +#else
> +/* Both dst and src unalignment will be treated as unaligned copy */
> +#define RTE_ARM64_MEMCPY_IS_UNALIGNED_COPY(dst, src) \
> +	(((uintptr_t)(dst) | (uintptr_t)(src)) & RTE_ARM64_MEMCPY_ALIGN_MASK)
> +#endif
> +
> +
> +/*
> + * If copy size is larger than threshold, memcpy() will be used.
> + * Run "memcpy_perf_autotest" to determine the proper threshold.
> + */
> +#define RTE_ARM64_MEMCPY_ALIGNED_THRESHOLD       ((size_t)(0xffffffff))
> +#define RTE_ARM64_MEMCPY_UNALIGNED_THRESHOLD     ((size_t)(0xffffffff))
> +
> +/*
> + * The logic of USE_RTE_MEMCPY() can also be modified to best fit platform.
> + */
> +#define USE_RTE_MEMCPY(dst, src, n) \
> +((!RTE_ARM64_MEMCPY_IS_UNALIGNED_COPY(dst, src) && \
> +n <= RTE_ARM64_MEMCPY_ALIGNED_THRESHOLD) \
> +|| (RTE_ARM64_MEMCPY_IS_UNALIGNED_COPY(dst, src) && \
> +n <= RTE_ARM64_MEMCPY_UNALIGNED_THRESHOLD))
> +
> +/**************************************
> + * End of customization section
> + **************************************/

Modifying the code to asjust the platform is not easy for deployment.
Can we move some customization variables inside the configuration file?