Thanks On Nov 17, 2009, at 1:08 PM, Jed Brown wrote:
> I think this is complete. > > http://petsc.cs.iit.edu/petsc/petsc-dev/rev/a36906938641 > > This was my first time messing with configure. It works in all > cases I > have tested, let me know if I screwed up. The default alignment is > now > 16, configurable via --with-memalign. Alignment of pointers > compiles to > (gcc-4.4.2/x86-64 at all positive optimization levels) > > lea r9,[r8+rbx*1+0xf] > and r9,0xfffffffffffffff0 > > so there should be no concern over runtime cost of alignment. If the > user provides their own malloc (via PetscMallocSet) which does not > provide the desired alignment then the first array will not have that > alignment (obviously) but every other will. It costs a few extra > bytes > per allocation but this should only add up to a few kB in real > applications. > > Jed >
