Re: [BK+PATCH] remove __constant_memcpy

[Timothy Miller <miller@techsource.com>]

Jeff Garzik wrote:

[snip]

>-		case 20:
>-			*(unsigned long *)to = *(const unsigned long *)from;
>-			*(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
>-			*(2+(unsigned long *)to) = *(2+(const unsigned long *)from);
>-			*(3+(unsigned long *)to) = *(3+(const unsigned long *)from);
>-			*(4+(unsigned long *)to) = *(4+(const unsigned long *)from);
>-			return to;
>-	}
>+	if (n <= 128)
>+		return __builtin_memcpy(to, from, n);
>+
> #define COMMON(x) \
> __asm__ __volatile__( \
> 	"rep ; movsl" \
>  
>

Ignorant questions since I haven't been following the discussion:  Does 
this work with unaligned copies?  Does it work well?  What's better, 
letting the CPU do realignment, or writing the code to do bit shifts so 
that both reads and writes are aligned?