This patch improves the 64-bit PowerPC InitialExec TLS support by providing

for a wider range of GOT entries that can hold thread-relative offsets.
This matches the behavior of GCC, which was not documented in the PPC64 TLS
ABI.  The ABI will be updated with the new code sequence.

Former sequence:

  ld 9,x@got@tprel(2)
  add 9,9,x@tls

New sequence:

  addis 9,2,x@got@tprel@ha
  ld 9,x@got@tprel@l(9)
  add 9,9,x@tls

Note that a linker optimization exists to transform the new sequence into
the shorter sequence when appropriate, by replacing the addis with a nop
and modifying the base register and relocation type of the ld.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170209 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 9 insertions, 4 deletions

diff --git a/lib/Target/PowerPC/PPCISelLowering.h b/lib/Target/PowerPC/PPCISelLowering.h
index f36fbfd..12b3df7 100644
--- a/lib/Target/PowerPC/PPCISelLowering.h
+++ b/lib/Target/PowerPC/PPCISelLowering.h
@@ -178,11 +178,16 @@ namespace llvm {
       CR6SET,
       CR6UNSET,
 
-      /// G8RC = LD_GOT_TPREL Symbol, G8RReg - Used by the initial-exec
+      /// G8RC = ADDIS_GOT_TPREL_HA %X2, Symbol - Used by the initial-exec
+      /// TLS model, produces an ADDIS8 instruction that adds the GOT
+      /// base to sym@got@tprel@ha.
+      ADDIS_GOT_TPREL_HA,
+
+      /// G8RC = LD_GOT_TPREL_L 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,
+      /// and offset sym@got@tprel@l.  This completes the addition that
+      /// finds the offset of "sym" relative to the thread pointer.
+      LD_GOT_TPREL_L,
 
       /// G8RC = ADD_TLS G8RReg, Symbol - Used by the initial-exec TLS
       /// model, produces an ADD instruction that adds the contents of