This patch introduces initial-exec model support for thread-local storage

on 64-bit PowerPC ELF.

The patch includes code to handle external assembly and MC output with the
integrated assembler.  It intentionally does not support the "old" JIT.

For the initial-exec TLS model, the ABI requires the following to calculate
the address of external thread-local variable x:

 Code sequence            Relocation                  Symbol
  ld 9,x@got@tprel(2)      R_PPC64_GOT_TPREL16_DS      x
  add 9,9,x@tls            R_PPC64_TLS                 x

The register 9 is arbitrary here.  The linker will replace x@got@tprel
with the offset relative to the thread pointer to the generated GOT
entry for symbol x.  It will replace x@tls with the thread-pointer
register (13).

The two test cases verify correct assembly output and relocation output
as just described.

PowerPC-specific selection node variants are added for the two
instructions above:  LD_GOT_TPREL and ADD_TLS.  These are inserted
when an initial-exec global variable is encountered by
PPCTargetLowering::LowerGlobalTLSAddress(), and later lowered to
machine instructions LDgotTPREL and ADD8TLS.  LDgotTPREL is a pseudo
that uses the same LDrs support added for medium code model's LDtocL,
with a different relocation type.

The rest of the processing is straightforward.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169281 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 14 insertions, 0 deletions

diff --git a/lib/Target/PowerPC/PPCISelLowering.h b/lib/Target/PowerPC/PPCISelLowering.h
index c20356c041..f54a8b77a4 100644
--- a/lib/Target/PowerPC/PPCISelLowering.h
+++ b/lib/Target/PowerPC/PPCISelLowering.h
@@ -178,6 +178,20 @@ namespace llvm {
       CR6SET,
       CR6UNSET,
 
+      /// G8RC = LD_GOT_TPREL Symbol, G8RReg - Used by the initial-exec
+      /// TLS model, produces a LD instruction with base register G8RReg
+      /// and offset sym@got@tprel.  The latter identifies the GOT entry
+      /// containing the offset of "sym" relative to the thread pointer.
+      LD_GOT_TPREL,
+
+      /// G8RC = ADD_TLS G8RReg, Symbol - Used by the initial-exec TLS
+      /// model, produces an ADD instruction that adds the contents of
+      /// G8RReg to the thread pointer.  Symbol contains a relocation
+      /// sym@tls which is to be replaced by the thread pointer and
+      /// identifies to the linker that the instruction is part of a
+      /// TLS sequence.
+      ADD_TLS,
+
       /// STD_32 - This is the STD instruction for use with "32-bit" registers.
       STD_32 = ISD::FIRST_TARGET_MEMORY_OPCODE,