Arun Raghavan wrote: > > > On Fri, 27 May 2016, at 10:07 PM, Rex Dieter wrote: >> Rex Dieter wrote: >> >> > Felipe Sateler wrote: >> > >> >>> Is there some reason you can't /build/ with SSE2 support on the >> >>> compiler? Or were you suggesting that we needed to add compiler >> >>> flags to make this work? >> >> >> >> My fear is that enabling SSE2 support globally for the library might >> >> induce gcc to use SSE2 instructions in its generated code. See the >> >> -msse section in the gcc manual[1]: >> >> >> >>> In particular, the file containing the CPU detection code should be >> >>> compiled without these options. >> >> >> >> So, I think what is needed is to split sse-using functions to a >> >> separate file and add -msse2 only to that file. However, I am not very >> >> confident I understand this very well, so this may not be optimal >> >> either. >> > >> > Ah, sneaky, if that's true, the approach I took in the initial patches >> > I posted elsewhere in this thread aren't ideal either. >> > >> > I'll go back and see if I can work up something better. >> >> OK, this version applies the -msse2 flag only to the source objects that >> need it, and it at least compiles. No runtime testing done yet. >> >> (I'll do more testing, and followup if I find anything more is needed) > > Were you able to test this out? The approach looks okay to me,. Yes, only rudimentary runtime testing (on i686) so far though. -- Rex
