On Fri, Nov 13, 2009 at 11:09 PM, Barry Smith <bsmith at mcs.anl.gov> wrote: > > > ? Good point, I have removed it. > > ? I put it in because I wanted an easy way to test that PETSc double arrays > are always 8 byte aligned (and the unaligned struct values were giving me > lots of false alarms). > > ? I guess we can test for double align on x86_64 systems. > > ? Barry > > The IBM BlueGene doesn't like 4 byte aligned doubles and sends a bus error > after a certain number are generated, Thus I was motivated to make PETSc a > bit clearer on that. >
But then the compiler in the BlueGene does not -malign-double by default? That would be weird and annoying... > > On Nov 12, 2009, at 9:29 AM, Lisandro Dalcin wrote: > >> On Wed, Nov 11, 2009 at 11:02 PM, Barry Smith <bsmith at mcs.anl.gov> wrote: >>> >>> ?Satish, >>> >>> ? gcc supports the option ?-malign-double on some systems. Please add it >>> to >>> the flags that configure checks for c and c++ and have it added if it >>> exists. >>> >> >> Definitely -1. Why are you asking for this? On x86_64 this is the >> default. In i386, this flag is likely going to break ABI's. >> >> >> -- >> Lisandro Dalc?n >> --------------- >> Centro Internacional de M?todos Computacionales en Ingenier?a (CIMEC) >> Instituto de Desarrollo Tecnol?gico para la Industria Qu?mica (INTEC) >> Consejo Nacional de Investigaciones Cient?ficas y T?cnicas (CONICET) >> PTLC - G?emes 3450, (3000) Santa Fe, Argentina >> Tel/Fax: +54-(0)342-451.1594 > > -- Lisandro Dalc?n --------------- Centro Internacional de M?todos Computacionales en Ingenier?a (CIMEC) Instituto de Desarrollo Tecnol?gico para la Industria Qu?mica (INTEC) Consejo Nacional de Investigaciones Cient?ficas y T?cnicas (CONICET) PTLC - G?emes 3450, (3000) Santa Fe, Argentina Tel/Fax: +54-(0)342-451.1594
