Re: [BK+PATCH] remove __constant_memcpy

[Linus Torvalds]

On Thu, 17 Apr 2003, Jeff Garzik wrote:
> 
> __constant_memcpy was used for small, constant-sized cases AFTER
> the kernel made the decision not to hand the copy duties over to the
> kernel's MMX/SSE code.  Take a look at the bottom of the patch below,
> and also this snip from a non-hacked string.h, for illustration...

This is the part I don't like

 #define memcpy(t, f, n) \
 (__builtin_constant_p(n) ? \
- __constant_memcpy((t),(f),(n)) : \
+ __builtin_memcpy((t),(f),(n)) : \
  __memcpy((t),(f),(n)))

Notice? Our old __constant_memcpy() would do the rigth thing for large 
copies. In conrast, I don't know that gcc will do so.

		Linus