Re: movmemm pattern

2010-10-26 Thread Richard Guenther
On Tue, Oct 26, 2010 at 1:12 PM, Paul Koning wrote: > > On Oct 26, 2010, at 1:27 PM, Dave Korn wrote: > >> On 26/10/2010 17:16, Paul Koning wrote: >>> On Oct 25, 2010, at 9:28 PM, Dave Korn wrote: ... What happens if you dereference i and j before the memcpy in foo?  Do you the

Re: movmemm pattern

2010-10-26 Thread Paul Koning
On Oct 26, 2010, at 1:27 PM, Dave Korn wrote: > On 26/10/2010 17:16, Paul Koning wrote: >> On Oct 25, 2010, at 9:28 PM, Dave Korn wrote: >>> ... >>> >>> What happens if you dereference i and j before the memcpy in foo? Do you >>> then get int-sized shared alignment in movmemM? >>> >>> extern i

Re: movmemm pattern

2010-10-26 Thread Dave Korn
On 26/10/2010 17:16, Paul Koning wrote: > On Oct 25, 2010, at 9:28 PM, Dave Korn wrote: > >> On 26/10/2010 01:53, Paul Koning wrote: >>> On Oct 25, 2010, at 3:44 PM, Richard Guenther wrote: >>> On Mon, Oct 25, 2010 at 11:26 AM, Paul Koning wrote: > Question on movmemm: > > G

Re: movmemm pattern

2010-10-26 Thread Paul Koning
On Oct 25, 2010, at 9:28 PM, Dave Korn wrote: > On 26/10/2010 01:53, Paul Koning wrote: >> On Oct 25, 2010, at 3:44 PM, Richard Guenther wrote: >> >>> On Mon, Oct 25, 2010 at 11:26 AM, Paul Koning >>> wrote: Question on movmemm: Given extern int *i, *j; void foo (void

Re: movmemm pattern

2010-10-26 Thread Joseph S. Myers
On Mon, 25 Oct 2010, Richard Guenther wrote: > Because the int * could point to unaligned data and there is no access > that would prove otherwise (memcpy accepts any alignment). As previously discussed, in ISO C storing a pointer in a particular pointer type or converting to / through that type

Re: movmemm pattern

2010-10-25 Thread Dave Korn
On 26/10/2010 01:53, Paul Koning wrote: > On Oct 25, 2010, at 3:44 PM, Richard Guenther wrote: > >> On Mon, Oct 25, 2010 at 11:26 AM, Paul Koning >> wrote: >>> Question on movmemm: >>> >>> Given >>> >>> extern int *i, *j; void foo (void) { memcpy (i, j, 10); } >>> >>> I would expect to see arg

Re: movmemm pattern

2010-10-25 Thread Paul Koning
On Oct 25, 2010, at 3:44 PM, Richard Guenther wrote: > On Mon, Oct 25, 2010 at 11:26 AM, Paul Koning wrote: >> Question on movmemm: >> >> Given >> >> extern int *i, *j; >> void foo (void) { memcpy (i, j, 10); } >> >> I would expect to see argument 4 (the shared alignment) to be sizeof(int) >

Re: movmemm pattern

2010-10-25 Thread Richard Guenther
On Mon, Oct 25, 2010 at 11:26 AM, Paul Koning wrote: > Question on movmemm: > > Given > > extern int *i, *j; > void foo (void) { memcpy (i, j, 10); } > > I would expect to see argument 4 (the shared alignment) to be sizeof(int) > since both argument are pointers to int.  What I get instead is 1.