[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
diff --git a/test/CodeGen/PowerPC/tls-ld.ll b/test/CodeGen/PowerPC/tls-ld.ll
index 4b7aae5..db02a56 100644
--- a/test/CodeGen/PowerPC/tls-ld.ll
+++ b/test/CodeGen/PowerPC/tls-ld.ll
@@ -18,7 +18,7 @@
; CHECK: addis [[REG:[0-9]+]], 2, a@got@tlsld@ha
; CHECK-NEXT: addi 3, [[REG]], a@got@tlsld@l
-; CHECK: bl __tls_get_addr(a@TLSLD)
+; CHECK: bl __tls_get_addr(a@tlsld)
; CHECK-NEXT: nop
; CHECK: addis [[REG2:[0-9]+]], 3, a@dtprel@ha
; CHECK-NEXT: addi {{[0-9]+}}, [[REG2]], a@dtprel@l