diff options
| author | Ulrich Weigand <ulrich.weigand@de.ibm.com> | 2013-07-09 16:41:09 +0000 |
|---|---|---|
| committer | Ulrich Weigand <ulrich.weigand@de.ibm.com> | 2013-07-09 16:41:09 +0000 |
| commit | 7a34599db017a5486cf7cd11eb124984acec8286 (patch) | |
| tree | a23293cc9969724b040480b643b18de412ea1ce9 /test/CodeGen/PowerPC/tls-gd.ll | |
| parent | f2cfef8172fd2eceb036b8caff50623a189ba2ff (diff) | |
| download | llvm-7a34599db017a5486cf7cd11eb124984acec8286.tar.gz llvm-7a34599db017a5486cf7cd11eb124984acec8286.tar.bz2 llvm-7a34599db017a5486cf7cd11eb124984acec8286.tar.xz | |
[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
Diffstat (limited to 'test/CodeGen/PowerPC/tls-gd.ll')
| -rw-r--r-- | test/CodeGen/PowerPC/tls-gd.ll | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/test/CodeGen/PowerPC/tls-gd.ll b/test/CodeGen/PowerPC/tls-gd.ll index 84c654ff69..5f0ef9a050 100644 --- a/test/CodeGen/PowerPC/tls-gd.ll +++ b/test/CodeGen/PowerPC/tls-gd.ll @@ -18,6 +18,6 @@ entry: ; CHECK: addis [[REG:[0-9]+]], 2, a@got@tlsgd@ha ; CHECK-NEXT: addi 3, [[REG]], a@got@tlsgd@l -; CHECK: bl __tls_get_addr(a@TLSGD) +; CHECK: bl __tls_get_addr(a@tlsgd) ; CHECK-NEXT: nop |