[PowerPC] Fix problems with large code model (PR17169).

Large code model on PPC64 requires creating and referencing TOC entries when
using the addis/ld form of addressing.  This was not being done in all cases.
The changes in this patch to PPCAsmPrinter::EmitInstruction() fix this.  Two
test cases are also modified to reflect this requirement.

Fast-isel was not creating correct code for loading floating-point constants
using large code model.  This also requires the addis/ld form of addressing.
Previously we were using the addis/lfd shortcut which is only applicable to
medium code model.  One test case is modified to reflect this requirement.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190882 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCFastISel.cpp b/lib/Target/PowerPC/PPCFastISel.cpp
index 09cc21b..4f8e6c1 100644
--- a/lib/Target/PowerPC/PPCFastISel.cpp
+++ b/lib/Target/PowerPC/PPCFastISel.cpp
@@ -1821,10 +1821,19 @@
     // Otherwise we generate LF[SD](Idx[lo], ADDIStocHA(X2, Idx)).
     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(PPC::ADDIStocHA),
             TmpReg).addReg(PPC::X2).addConstantPoolIndex(Idx);
-    BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(Opc), DestReg)
-      .addConstantPoolIndex(Idx, 0, PPCII::MO_TOC_LO)
-      .addReg(TmpReg)
-      .addMemOperand(MMO);
+    // But for large code model, we must generate a LDtocL followed
+    // by the LF[SD].
+    if (CModel == CodeModel::Large) {
+      unsigned TmpReg2 = createResultReg(&PPC::G8RC_and_G8RC_NOX0RegClass);
+      BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(PPC::LDtocL),
+              TmpReg2).addConstantPoolIndex(Idx).addReg(TmpReg);
+      BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(Opc), DestReg)
+        .addImm(0).addReg(TmpReg2);
+    } else 
+      BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(Opc), DestReg)
+        .addConstantPoolIndex(Idx, 0, PPCII::MO_TOC_LO)
+        .addReg(TmpReg)
+        .addMemOperand(MMO);
   }
 
   return DestReg;