On 9 May 2012 17:19, leif <not.rea...@online.de> wrote: > Bill Hart wrote: >> >> Thanks for the information. I am forwarding this to mpir-devel to see >> what Jason thinks about possibly disabling '-fstrict-aliasing' >> upstream for builds on Debian gcc 4.3.2. > > > Well, in Sage we'd mainly need to bypass the test (or add > '-fno-strict-aliasing') to bootstrap the GCC (4.6.3) spkg; after that's been > built, MPIR and MPFR are rebuilt with the new compiler. > > For MPIR, it would probably make sense to add the test case from PR 36765, > and if that fails, either bail out or work around the bug (with a warning, > by disabling strict aliasing).
Ah yes, that sounds like a good plan. In fact, shouldn't autotools eventually catch up and fix this automatically? Maybe it already has.... Bill. > > > -leif > > > >> I wonder how much of a performance hit is involved. >> >> Bill. >> >> On 9 May 2012 16:23, leif<not.rea...@online.de> wrote: >>> >>> Jeroen Demeyer wrote: >>>> >>>> >>>> On 2012-05-06 23:22, Alexander Dreyer wrote: >>>>> >>>>> >>>>> Hi! >>>>> built and made ptestlong sucessfully on SuSE Enterprise 11. >>>>> >>>>> But I had to hack mpir to accept gcc 4.3.2 64bits: configure had >>>>> hard-coded not to build on this platform, because the original gcc >>>>> 4.3.2 >>>>> was buggy, but mine is patched. (The mpir guys do not test the actual >>>>> bug, but just look for gcc's version.) >>>> >>>> >>>> >>>> I agree, hardcoding that bad version isn't a good idea. Also because >>>> MPIR might just work well enough to build GCC. >>> >>> >>> >>> Turns out that apparently only Debian's GCC 4.3.2 is affected (not >>> vanilla >>> FSF), and only if '-fstrict-aliasing' is enabled (which is the case with >>> '-O2'.) >>> >>> See: >>> >>> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=524472 >>> >>> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36765 >>> >>> >>> So we should probably patch MPIR's 'configure'. >>> >>> >>> -leif >>> >>> >>> -- >>> () The ASCII Ribbon Campaign >>> /\ Help Cure HTML E-Mail >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "sage-release" group. >>> To post to this group, send email to sage-rele...@googlegroups.com. >>> To unsubscribe from this group, send email to >>> sage-release+unsubscr...@googlegroups.com. >>> For more options, visit this group at >>> http://groups.google.com/group/sage-release?hl=en. >>> >> > > > -- > () The ASCII Ribbon Campaign > /\ Help Cure HTML E-Mail > > -- > You received this message because you are subscribed to the Google Groups > "mpir-devel" group. > To post to this group, send email to mpir-devel@googlegroups.com. > To unsubscribe from this group, send email to > mpir-devel+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/mpir-devel?hl=en. > -- You received this message because you are subscribed to the Google Groups "mpir-devel" group. To post to this group, send email to mpir-devel@googlegroups.com. To unsubscribe from this group, send email to mpir-devel+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/mpir-devel?hl=en.
