[PowerPC] Load BlockAddress values from the TOC in 64-bit SVR4 code

Since block address values can be larger than 2GB in 64-bit code, they
cannot be loaded simply using an @l / @ha pair, but instead must be
loaded from the TOC, just like GlobalAddress, ConstantPool, and
JumpTable values are.

The commit also fixes a bug in PPCLinuxAsmPrinter::doFinalization where
temporary labels could not be used as TOC values, since code would
attempt (and fail) to use GetOrCreateSymbol to create a symbol of the
same name as the temporary label.

llvm-svn: 220959
diff --git a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
index 5b68a9eaa..0333888 100644
--- a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -385,7 +385,7 @@
     const MachineOperand &MO = MI->getOperand(1);
 
     // Map symbol -> label of TOC entry
-    assert(MO.isGlobal() || MO.isCPI() || MO.isJTI());
+    assert(MO.isGlobal() || MO.isCPI() || MO.isJTI() || MO.isBlockAddress());
     MCSymbol *MOSymbol = nullptr;
     if (MO.isGlobal())
       MOSymbol = getSymbol(MO.getGlobal());
@@ -393,6 +393,8 @@
       MOSymbol = GetCPISymbol(MO.getIndex());
     else if (MO.isJTI())
       MOSymbol = GetJTISymbol(MO.getIndex());
+    else if (MO.isBlockAddress())
+      MOSymbol = GetBlockAddressSymbol(MO.getBlockAddress());
 
     MCSymbol *TOCEntry = lookUpOrCreateTOCEntry(MOSymbol);
 
@@ -409,6 +411,7 @@
   }
   case PPC::LDtocJTI:
   case PPC::LDtocCPT:
+  case PPC::LDtocBA:
   case PPC::LDtoc: {
     // Transform %X3 = LDtoc <ga:@min1>, %X2
     LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());
@@ -419,7 +422,7 @@
     const MachineOperand &MO = MI->getOperand(1);
 
     // Map symbol -> label of TOC entry
-    assert(MO.isGlobal() || MO.isCPI() || MO.isJTI());
+    assert(MO.isGlobal() || MO.isCPI() || MO.isJTI() || MO.isBlockAddress());
     MCSymbol *MOSymbol = nullptr;
     if (MO.isGlobal())
       MOSymbol = getSymbol(MO.getGlobal());
@@ -427,6 +430,8 @@
       MOSymbol = GetCPISymbol(MO.getIndex());
     else if (MO.isJTI())
       MOSymbol = GetJTISymbol(MO.getIndex());
+    else if (MO.isBlockAddress())
+      MOSymbol = GetBlockAddressSymbol(MO.getBlockAddress());
 
     MCSymbol *TOCEntry = lookUpOrCreateTOCEntry(MOSymbol);
 
@@ -448,7 +453,8 @@
     // reference the symbol directly.
     TmpInst.setOpcode(PPC::ADDIS8);
     const MachineOperand &MO = MI->getOperand(2);
-    assert((MO.isGlobal() || MO.isCPI() || MO.isJTI()) &&
+    assert((MO.isGlobal() || MO.isCPI() || MO.isJTI() ||
+            MO.isBlockAddress()) &&
            "Invalid operand for ADDIStocHA!");
     MCSymbol *MOSymbol = nullptr;
     bool IsExternal = false;
@@ -468,9 +474,12 @@
       MOSymbol = GetCPISymbol(MO.getIndex());
     else if (MO.isJTI())
       MOSymbol = GetJTISymbol(MO.getIndex());
+    else if (MO.isBlockAddress())
+      MOSymbol = GetBlockAddressSymbol(MO.getBlockAddress());
 
     if (IsExternal || IsNonLocalFunction || IsCommon || IsAvailExt ||
-        MO.isJTI() || TM.getCodeModel() == CodeModel::Large)
+        MO.isJTI() || MO.isBlockAddress() ||
+        TM.getCodeModel() == CodeModel::Large)
       MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
 
     const MCExpr *Exp =
@@ -489,12 +498,17 @@
     // associated TOC entry.  Otherwise reference the symbol directly.
     TmpInst.setOpcode(PPC::LD);
     const MachineOperand &MO = MI->getOperand(1);
-    assert((MO.isGlobal() || MO.isJTI() || MO.isCPI()) &&
+    assert((MO.isGlobal() || MO.isCPI() || MO.isJTI() ||
+            MO.isBlockAddress()) &&
            "Invalid operand for LDtocL!");
     MCSymbol *MOSymbol = nullptr;
 
     if (MO.isJTI())
       MOSymbol = lookUpOrCreateTOCEntry(GetJTISymbol(MO.getIndex()));
+    else if (MO.isBlockAddress()) {
+      MOSymbol = GetBlockAddressSymbol(MO.getBlockAddress());
+      MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
+    }
     else if (MO.isCPI()) {
       MOSymbol = GetCPISymbol(MO.getIndex());
       if (TM.getCodeModel() == CodeModel::Large)
@@ -978,7 +992,7 @@
     for (MapVector<MCSymbol*, MCSymbol*>::iterator I = TOC.begin(),
          E = TOC.end(); I != E; ++I) {
       OutStreamer.EmitLabel(I->second);
-      MCSymbol *S = OutContext.GetOrCreateSymbol(I->first->getName());
+      MCSymbol *S = I->first;
       if (isPPC64)
         TS.emitTCEntry(*S);
       else