Re: [Patch PING]: Trivial gcc.dg/visibility-11.c fix for x86_64

[Uros Bizjak <ubizjak at gmail dot com>]

Jan Hubicka wrote:

> > > > 	2006-07-03 Uros Bizjak <uros@kss-loka.si>
> > > >
> > > > 	* gcc.dg/visibility-11.c: Enlarge test array to 1024 bytes to
> > > > 	avoid memcpy optimization.
> > > >        
> > This is OK for mainline, and for the gcc-4_1-branch as the same
> > testsuite failure shows up there?  Thanks for fixing this.
> >    
>
> Note that I have patch that will make memcpy inlines for 1024 bytes too
> (it is still within limit where function call is measurable).  I wouild
> suggest adding at least two extra 0.
>  
This would be a different problem. gcc.dg/visibility-11.c testcase uses 
-Os to make sure that memcpy is not expanded as "store by pieces" 
sequence. However, MOVE_MAX_PIECES is different for x86_64 than for i386:

#define MOVE_MAX_PIECES (TARGET_64BIT ? 8 : 4)

and memcpy is still expanded as "store by pieces", even for -Os, as the 
condition

#define STORE_BY_PIECES_P(SIZE, ALIGN) \
 (move_by_pieces_ninsns (SIZE, ALIGN, STORE_MAX_PIECES + 1) \
  < (unsigned int) MOVE_RATIO)

is true, where:

#define STORE_MAX_PIECES  MIN (MOVE_MAX_PIECES, 2 * sizeof (HOST_WIDE_INT))

and

#define MOVE_RATIO (optimize_size ? 3 : ix86_cost->move_ratio)

Uros.