This patch implements local-dynamic TLS model support for the 64-bit

PowerPC target.  This is the last of the four models, so we now have 
full TLS support.

This is mostly a straightforward extension of the general dynamic model.
I had to use an additional Chain operand to tie ADDIS_DTPREL_HA to the
register copy following ADDI_TLSLD_L; otherwise everything above the
ADDIS_DTPREL_HA appeared dead and was removed.

As before, there are new test cases to test the assembly generation, and
the relocations output during integrated assembly.  The expected code
gen sequence can be read in test/CodeGen/PowerPC/tls-ld.ll.

There are a couple of things I think can be done more efficiently in the
overall TLS code, so there will likely be a clean-up patch forthcoming;
but for now I want to be sure the functionality is in place.

Bill


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170003 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 34 insertions, 4 deletions

diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index 1402718f71..68f1bc6eae 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -583,6 +583,11 @@ const char *PPCTargetLowering::getTargetNodeName(unsigned Opcode) const {
   case PPCISD::ADDIS_TLSGD_HA:  return "PPCISD::ADDIS_TLSGD_HA";
   case PPCISD::ADDI_TLSGD_L:    return "PPCISD::ADDI_TLSGD_L";
   case PPCISD::GET_TLS_ADDR:    return "PPCISD::GET_TLS_ADDR";
+  case PPCISD::ADDIS_TLSLD_HA:  return "PPCISD::ADDIS_TLSLD_HA";
+  case PPCISD::ADDI_TLSLD_L:    return "PPCISD::ADDI_TLSLD_L";
+  case PPCISD::GET_TLSLD_ADDR:  return "PPCISD::GET_TLSLD_ADDR";
+  case PPCISD::ADDIS_DTPREL_HA: return "PPCISD::ADDIS_DTPREL_HA";
+  case PPCISD::ADDI_DTPREL_L:   return "PPCISD::ADDI_DTPREL_L";
   }
 }
 
@@ -1373,14 +1378,39 @@ SDValue PPCTargetLowering::LowerGlobalTLSAddress(SDValue Op,
     SDValue ParmReg = DAG.getRegister(PPC::X3, MVT::i64);
     SDValue TLSAddr = DAG.getNode(PPCISD::GET_TLS_ADDR, dl,
                                   PtrVT, ParmReg, TGA);
-    // The call to GET_TLS_ADDR really is in X3 already, but
-    // some hacks are needed here to tie everything together.
-    // The extra copies dissolve during subsequent transforms.
+    // The return value from GET_TLS_ADDR really is in X3 already, but
+    // some hacks are needed here to tie everything together.  The extra
+    // copies dissolve during subsequent transforms.
     Chain = DAG.getCopyToReg(Chain, dl, PPC::X3, TLSAddr);
     return DAG.getCopyFromReg(Chain, dl, PPC::X3, PtrVT);
   }
 
-  llvm_unreachable("local-dynamic TLS mode is not yet supported");
+  if (Model == TLSModel::LocalDynamic) {
+    SDValue TGA = DAG.getTargetGlobalAddress(GV, dl, PtrVT, 0, 0);
+    SDValue GOTReg = DAG.getRegister(PPC::X2, MVT::i64);
+    SDValue GOTEntryHi = DAG.getNode(PPCISD::ADDIS_TLSLD_HA, dl, PtrVT,
+                                     GOTReg, TGA);
+    SDValue GOTEntry = DAG.getNode(PPCISD::ADDI_TLSLD_L, dl, PtrVT,
+                                   GOTEntryHi, TGA);
+
+    // We need a chain node, and don't have one handy.  The underlying
+    // call has no side effects, so using the function entry node
+    // suffices.
+    SDValue Chain = DAG.getEntryNode();
+    Chain = DAG.getCopyToReg(Chain, dl, PPC::X3, GOTEntry);
+    SDValue ParmReg = DAG.getRegister(PPC::X3, MVT::i64);
+    SDValue TLSAddr = DAG.getNode(PPCISD::GET_TLSLD_ADDR, dl,
+                                  PtrVT, ParmReg, TGA);
+    // The return value from GET_TLSLD_ADDR really is in X3 already, but
+    // some hacks are needed here to tie everything together.  The extra
+    // copies dissolve during subsequent transforms.
+    Chain = DAG.getCopyToReg(Chain, dl, PPC::X3, TLSAddr);
+    SDValue DtvOffsetHi = DAG.getNode(PPCISD::ADDIS_DTPREL_HA, dl, PtrVT,
+                                      ParmReg, TGA, Chain);
+    return DAG.getNode(PPCISD::ADDI_DTPREL_L, dl, PtrVT, DtvOffsetHi, TGA);
+  }
+
+  llvm_unreachable("Unknown TLS model!");
 }
 
 SDValue PPCTargetLowering::LowerGlobalAddress(SDValue Op,