This discussion went off-topic quite some time ago. Please let this die.
cgf On Sat, May 26, 2012 at 08:51:22PM -0400, Tim Prince wrote: >On 05/26/2012 07:40 PM, Linda Walsh wrote: >> >> >> Every time you fetch a word or instruction that is not 8-byte >> aligned, >> you force a fatal (but caught by the processor and/or OS) signal for >> unaligned >> data. That forces execution out of the pipeline (though not likely >> out of >> cache, sadly, due to frequency of occurrence). That's not counting >> the extra >> cycles to fetch the rest of the data. On some machines that can >> easily amount >> to several dozen instructions worth. >> >There have been compilers for 32-bit Windows for 20 years which gave >8-byte alignments by default. cygwin changed the default configure >parameter in binutils so as to support alignment about 8 years ago. It >was tolerable to some before then as it matters only for 64-bit and >larger objects (doubles, and SSE, after that was introduced). The >characteristics of the worst compiler (with respect to alignment) >available outside of cygwin don't have a bearing on this list. >If the powers that be have decided that 64-bit mode should be supported >on cygwin setup.exe only by mingw cross compilers, I'll accept that. > >-- >Tim Prince > > >-- >Problem reports: http://cygwin.com/problems.html >FAQ: http://cygwin.com/faq/ >Documentation: http://cygwin.com/docs.html >Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple > > -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
