On Oct 23, 2011, at 1:59 PM, David Edelsohn wrote: > On Sun, Oct 23, 2011 at 10:16 AM, Perry Smith <pedz...@gmail.com> wrote: > >> libgomp.so.1 wants libc.a, libpthreads.a, and libgcc_s.a. The first two do >> not present a problem. But there are four libgcc_s.a (normal, ppc64, >> pthread, and ppc64+pthread). >> >> Note that there is also four versions of libgomp.so.1 (normal, ppc64, >> pthread, ppc64+pthread). >> >> My question is: which libgcc_s.a should I link to? (this question is for >> each of the four versions of libgomp.so.1). >> >> Setting LIBPATH or whatever I do is going to override the internal path >> (since the internal path is broken). So, this may be a question that has >> never been asked or answered. >> >> My knee jerk is that the normal libgomp.so.1 wants the normal libgcc_s.a, >> the ppc64 wants the ppc64, etc. But I notice that it will always include >> pthread so that is what caused me to pause and ask. >> >> Part of me wonders if the two non-pthread versions of libgomp make any >> sense. I don't really know anything about libgomp. > > libgomp (-fopenmp) does not make sense without pthreads. -fopenmp > implies pthreads. > > One thing to note: AIX tools default to 32 bit mode, although all > systems are 64 bit, unlike GNU/Linux, which defaults to 64 bit mode > (on x86-64 and PPC64). > > Only two of the four libgomp multilibs truly are necessary, but > avoiding the non-pthread builds is not worth the trouble. The > non-pthread libgomp libraries never will be used, unless GCC is > invoked incorrectly. Each library, including libgomp, should list its > multilib install directory first, e.g., ppc64 pthread would be > > -Wl,-blibpath:.../lib/gcc/powerpc-ibm-aix6.1.3.0/4.6.0/pthread/ppc64:.../lib/pthread/ppc64:/usr/lib:/lib > > and default would be > > -Wl,-blibpath:.../lib/gcc/powerpc-ibm-aix6.1.3.0/4.6.0:.../lib:/usr/lib:/lib > > The GCC build process and driver directory search process make a lot > of assumptions that the system directories follow a Linux/SVR4/Solaris > layout. To follow AIX style, the PPC64 and PPC32 non-reentrant > (non-pthreads) libraries should be archived into the same file > libgomp.a (which never would be referenced) and the reentrant > (pthreads) libraries for PPC64 and PPC32 should be archived into > libgomp_r.a. The benefit has not been shown to be worth the effort.
Thanks David, One more question on this quest (drifting a little more off topic). In my log files I see a lot of these errors: > ld: 0711-768 WARNING: Object > ../libsupc++/.libs/libsupc++convenience.a[eh_terminate.o], section 1, > function .std::terminate(): > The branch at address 0x10c is not followed by a recognized no-op > or TOC-reload instruction. The unrecognized instruction is 0x0. The build continues and completes. I just want to make sure that I can safely ignore them. Surfing the web, sometimes I see people flag the as errors and other times not. Thank you again, pedz
