https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64941
Bug ID: 64941
Summary: -O3 breaks tar
Product: gcc
Version: 4.8.3
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: brian at soulspark dot org
While emerging my gentoo I ended up with a version of tar-1.27.1 that wouldn't
extract one particular package: sys-apps/kbd-1.15.5 (although it worked on
other packages)
The compiled executable produced an error message when attempting to decompress
and untar the file:
tar xf /usr/portage/distfiles/kbd-1.15.5.tar.gz
tar: Skipping to next header
tar: Exiting with failure status due to previous errors
After a bit of trial and error I found if I changed the CFLAGS from:
1) CFLAGS = "-fomit-frame-pointer -pipe -march=native -mtune=native
-fexcess-precision=fast -O3"
to:
2) CFLAGS="-march=native -mtune=native -O2 -pipe -fomit-frame-pointer
-fexcess-precision=fast"
then the code would work as designed.
This is a 64 bit system with abi_32 enabled, but I don't think that makes any
difference in this case.
Steps to reproduce: using gcc 4.8.3 compile the attached tar, the run the
executable to extract the attached kbd. It will fail with the error message
above.
Change to -O2 and it will work fine.
