svn commit: r333324 - in head/sys: amd64/amd64 conf

[Rodney W. Grimes]

> Author: mjg
> Date: Mon May  7 15:07:28 2018
> New Revision: 333324
> URL: https://svnweb.freebsd.org/changeset/base/333324
> 
> Log:
>   amd64: replace libkern's memset and memmove with assembly variants
>   
>   memmove is repurposed bcopy (arguments swapped, return value added)
>   The libkern variant is a wrapper around bcopy, so this is a big
>   improvement.
>   
>   memset is repurposed memcpy. The librkern variant is doing fishy stuff,
>   including branching on 0 and calling bzero.
>   
>   Both functions are rather crude and subject to partial depessimization.
>   
>   This is a soft prerequisite to adding variants utilizing the
>   'Enhanced REP MOVSB/STOSB' bit and let the kernel patch at runtime.
> 
> Modified:
>   head/sys/amd64/amd64/support.S
>   head/sys/conf/files.amd64
> 
> Modified: head/sys/amd64/amd64/support.S
> ==============================================================================
> --- head/sys/amd64/amd64/support.S	Mon May  7 15:07:26 2018	(r333323)
> +++ head/sys/amd64/amd64/support.S	Mon May  7 15:07:28 2018	(r333324)
> @@ -162,6 +162,58 @@ ENTRY(bcopy)
>  END(bcopy)
>  
>  /*
> + * memmove(dst, src, cnt)
> + *         rdi, rsi, rdx
> + * Original by:
> + *  ws at tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800

If the original is by ws at tools.de, who is this version by?
Or is this simply copied from some other FreeBSD file?

Thanks,
> + */
> +ENTRY(memmove)
> +	PUSH_FRAME_POINTER
> +	movq	%rdi,%r9
> +	movq	%rdx,%rcx
> +
> +	movq	%rdi,%rax
> +	subq	%rsi,%rax
> +	cmpq	%rcx,%rax			/* overlapping && src < dst? */
> +	jb	1f
> +
> +	shrq	$3,%rcx				/* copy by 64-bit words */
> +	rep
> +	movsq
> +	movq	%rdx,%rcx
> +	andq	$7,%rcx				/* any bytes left? */
> +	rep
> +	movsb
> +	movq	%r9,%rax
> +	POP_FRAME_POINTER
> +	ret
> +
> +	/* ALIGN_TEXT */
> +1:
> +	addq	%rcx,%rdi			/* copy backwards */
> +	addq	%rcx,%rsi
> +	decq	%rdi
> +	decq	%rsi
> +	andq	$7,%rcx				/* any fractional bytes? */
> +	std
> +	rep
> +	movsb
> +	movq	%rdx,%rcx			/* copy remainder by 32-bit words */
> +	shrq	$3,%rcx
> +	subq	$7,%rsi
> +	subq	$7,%rdi
> +	rep
> +	movsq
> +	cld
> +	movq	%r9,%rax
> +	POP_FRAME_POINTER
> +	ret
> +END(memmove)
> +
> +/*
> + * memcpy(dst, src, len)
> + *        rdi, rsi, rdx
> + *
>   * Note: memcpy does not support overlapping copies
>   */
>  ENTRY(memcpy)
> @@ -178,6 +230,27 @@ ENTRY(memcpy)
>  	POP_FRAME_POINTER
>  	ret
>  END(memcpy)
> +
> +/*
> + * memset(dst, c,   len)
> + *        rdi, rsi, rdx
> + */
> +ENTRY(memset)
> +	PUSH_FRAME_POINTER
> +	movq	%rdi,%r9
> +	movq	%rdx,%rcx
> +	movq	%rsi,%rax
> +	shrq	$3,%rcx
> +	rep
> +	stosq
> +	movq	%rdx,%rcx
> +	andq	$7,%rcx
> +	rep
> +	stosb
> +	movq	%r9,%rax
> +	POP_FRAME_POINTER
> +	ret
> +END(memset)
>  
>  /*
>   * pagecopy(%rdi=from, %rsi=to)
> 
> Modified: head/sys/conf/files.amd64
> ==============================================================================
> --- head/sys/conf/files.amd64	Mon May  7 15:07:26 2018	(r333323)
> +++ head/sys/conf/files.amd64	Mon May  7 15:07:28 2018	(r333324)
> @@ -620,8 +620,6 @@ isa/vga_isa.c			optional	vga
>  kern/kern_clocksource.c		standard
>  kern/link_elf_obj.c		standard
>  libkern/x86/crc32_sse42.c	standard
> -libkern/memmove.c		standard
> -libkern/memset.c		standard
>  #
>  # IA32 binary support
>  #
> 
> 

-- 
Rod Grimes                                                 rgrimes at freebsd.org