I started trying to fix a small issue, but this code has seen a small fix too
many.
The old code was fairly convoluted. Some of the issues it had:
* It failed to check if a symbol difference was in the some section when
converting a relocation to pcrel.
* It failed to check if the relocation was already pcrel.
* The pcrel value computation was wrong in some cases (relocation-pc.s)
* It was missing quiet a few cases where it should not convert symbol
relocations to section relocations, leaving the backends to patch it up.
* It would not propagate the fact that it had changed a relocation to pcrel,
requiring a quiet nasty work around in ARM.
* It was missing comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205076 91177308-0d34-0410-b5e6-96231b3b80d8
Given
bar = foo + 4
.long bar
MC would eat the 4. GNU as includes it in the relocation. The rule seems to be
that a variable that defines a symbol is used in the relocation and one that
does not define a symbol is evaluated and the result included in the relocation.
Fixing this unfortunately required some other changes:
* Since the variable is now evaluated, it would prevent the ELF writer from
noticing the weakref marker the elf streamer uses. This patch then replaces
that with a VariantKind in MCSymbolRefExpr.
* Using VariantKind then requires us to look past other VariantKind to see
.weakref bar,foo
call bar@PLT
doing this also fixes
zed = foo +2
call zed@PLT
so that is a good thing.
* Looking past VariantKind means that the relocation selection has to use
the fixup instead of the target.
This is a reboot of the previous fixes for MC. I will watch the sanitizer
buildbot and wait for a build before adding back the previous fixes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204294 91177308-0d34-0410-b5e6-96231b3b80d8
This adds the actual lib/Target/SystemZ target files necessary to
implement the SystemZ target. Note that at this point, the target
cannot yet be built since the configure bits are missing. Those
will be provided shortly by a follow-on patch.
This version of the patch incorporates feedback from reviews by
Chris Lattner and Anton Korobeynikov. Thanks to all reviewers!
Patch by Richard Sandiford.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181203 91177308-0d34-0410-b5e6-96231b3b80d8
