llvm-6502/test/MC/PowerPC
Ulrich Weigand 7a34599db0 [PowerPC] Revert r185476 and fix up TLS variant kinds
In the commit message to r185476 I wrote:

>The PowerPC-specific modifiers VK_PPC_TLSGD and VK_PPC_TLSLD
>correspond exactly to the generic modifiers VK_TLSGD and VK_TLSLD.
>This causes some confusion with the asm parser, since VK_PPC_TLSGD
>is output as @tlsgd, which is then read back in as VK_TLSGD.
>
>To avoid this confusion, this patch removes the PowerPC-specific
>modifiers and uses the generic modifiers throughout.  (The only
>drawback is that the generic modifiers are printed in upper case
>while the usual convention on PowerPC is to use lower-case modifiers.
>But this is just a cosmetic issue.)

This was unfortunately incorrect, there is is fact another,
serious drawback to using the default VK_TLSLD/VK_TLSGD
variant kinds: using these causes ELFObjectWriter::RelocNeedsGOT
to return true, which in turn causes the ELFObjectWriter to emit
an undefined reference to _GLOBAL_OFFSET_TABLE_.

This is a problem on powerpc64, because it uses the TOC instead
of the GOT, and the linker does not provide _GLOBAL_OFFSET_TABLE_,
so the symbol remains undefined.  This means shared libraries
using TLS built with the integrated assembler are currently
broken.

While the whole RelocNeedsGOT / _GLOBAL_OFFSET_TABLE_ situation
probably ought to be properly fixed at some point, for now I'm
simply reverting the r185476 commit.  Now this in turn exposes
the breakage of handling @tlsgd/@tlsld in the asm parser that
this check-in was originally intended to fix.

To avoid this regression, I'm also adding a different fix for
this problem: while common code now parses @tlsgd as VK_TLSGD,
a special hack in the asm parser translates this code to the
platform-specific VK_PPC_TLSGD that the back-end now expects.
While this is not really pretty, it's self-contained and
shouldn't hurt anything else for now.  One the underlying
problem is fixed, this hack can be reverted again.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185945 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-09 16:41:09 +00:00
..
lit.local.cfg
ppc64-encoding-bookII.s [PowerPC] Support time base instructions 2013-07-08 15:20:38 +00:00
ppc64-encoding-ext.s
ppc64-encoding-fp.s
ppc64-encoding-vmx.s
ppc64-encoding.s [PowerPC] Support basic compare mnemonics 2013-07-08 14:49:37 +00:00
ppc64-errors.s [PowerPC] Support @tls in the asm parser 2013-07-05 12:22:36 +00:00
ppc64-fixup-apply.s [PowerPC] Support .llong and fix .word 2013-07-09 07:59:25 +00:00
ppc64-fixup-explicit.s
ppc64-fixups.s [PowerPC] Revert r185476 and fix up TLS variant kinds 2013-07-09 16:41:09 +00:00
ppc64-initial-cfa.s
ppc64-operands.s
ppc64-regs.s
ppc64-relocs-01.s
ppc64-tls-relocs-01.s
ppc-llong.s [PowerPC] Support .llong and fix .word 2013-07-09 07:59:25 +00:00
ppc-machine.s [PowerPC] Support ".machine any" 2013-07-09 10:00:34 +00:00
ppc-nop.s [PowerPC] Implement writeNopData 2013-07-04 18:28:46 +00:00
ppc-word.s [PowerPC] Support .llong and fix .word 2013-07-09 07:59:25 +00:00