On 01/23/2013 02:22 PM, Baho Utot wrote: > On 01/23/2013 02:10 PM, Bruce Dubbs wrote: >> Baho Utot wrote: >>> On 01/23/2013 12:43 PM, Philippe Delavalade wrote: >>>> Hi. >>>> >>>> When testing glibc in chapter 6, i obtain an error which looks like one of >>>> those signaled in the book but : >>>> >>>> make[2]: *** [/sources/glibc-build/rt/tst-cputimer1.out] Error 1 >>>> make[1]: *** [rt/tests] Error 2 >>>> >>>> Another error is marked as (ignored) but does not appear in the book : >>>> >>>> make[2]: [/sources/glibc-build/conform/run-conformtest.out] Error 1 >>>> (ignored) >>>> >>>> I guess I can go ahead but if someone can confirm :-) >>>> >>>> Thanks. >>>> >>> Are you on i686 or x86_64? >>> >>> I always had errors on i686 until I compiled glibc with the following >>> CFLAGS and CXXFLAGS >>> >>> -O2 -g -march=i486 -mtune=i686 -pipe >>> >>> Using those flags gives me a clean check with no errors at all. >> -march overrides -mtune. The later is only used if there is no >> appropriate -march setting (rarely).
-march=cpu-type Generate instructions for the machine type cpu-type. In contrast to -mtune=cpu-type, which merely tunes the generated code for the specified cpu-type, -march=cpu-type allows GCC to generate code that may not run at all on processors other than the one indicated. Specifying -march=cpu-type implies -mtune=cpu-type. -mtune=cpu-type Tune to cpu-type everything applicable about the generated code, except for the ABI and the set of available instructions. While picking a specific cpu-type schedules things appropriately for that particular chip, the compiler does not generate any code that cannot run on the default machine type unless you use a -march=cpu-type option. For example, if GCC is configured for i686-pc-linux-gnu then -mtune=pentium4 generates code that is tuned for Pentium 4 but still runs on i686 machines. > if I use -march=i686 mtune=i686 then the checks are not clean and > several fail > > >> -pipe is build optimization and doesn't do anything for the generated >> code. >> >> -g adds debugging info. Probably not needed and removed later with the >> strip command. >> >> -- Bruce >> -- http://linuxfromscratch.org/mailman/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/lfs/faq.html Unsubscribe: See the above information page
