[mips] Fix debug information for __thread variable

This patch fixes debug information for __thread variable on Mips
using .dtprelword and .dtpreldword directives.

Patch by Aleksandar Beserminji.

Differential Revision: http://reviews.llvm.org/D28770

llvm-svn: 292624

4 files changed, 27 insertions, 0 deletions

diff --git a/llvm/lib/Target/Mips/MipsAsmPrinter.cpp b/llvm/lib/Target/Mips/MipsAsmPrinter.cpp
index 179695bc698..04d6529a073 100644
--- a/llvm/lib/Target/Mips/MipsAsmPrinter.cpp
+++ b/llvm/lib/Target/Mips/MipsAsmPrinter.cpp
@@ -1037,6 +1037,22 @@ void MipsAsmPrinter::PrintDebugValueComment(const MachineInstr *MI,
   // TODO: implement
 }
 
+// Emit .dtprelword or .dtpreldword directive
+// and value for debug thread local expression.
+void MipsAsmPrinter::EmitDebugValue(const MCExpr *Value,
+                                          unsigned Size) const {
+  switch (Size) {
+  case 4:
+    OutStreamer->EmitDTPRel32Value(Value);
+    break;
+  case 8:
+    OutStreamer->EmitDTPRel64Value(Value);
+    break;
+  default:
+    llvm_unreachable("Unexpected size of expression value.");
+  }
+}
+
 // Align all targets of indirect branches on bundle size.  Used only if target
 // is NaCl.
 void MipsAsmPrinter::NaClAlignIndirectJumpTargets(MachineFunction &MF) {
diff --git a/llvm/lib/Target/Mips/MipsAsmPrinter.h b/llvm/lib/Target/Mips/MipsAsmPrinter.h
index 259e557e128..c5cf5241c23 100644
--- a/llvm/lib/Target/Mips/MipsAsmPrinter.h
+++ b/llvm/lib/Target/Mips/MipsAsmPrinter.h
@@ -140,6 +140,7 @@ public:
   void EmitStartOfAsmFile(Module &M) override;
   void EmitEndOfAsmFile(Module &M) override;
   void PrintDebugValueComment(const MachineInstr *MI, raw_ostream &OS);
+  void EmitDebugValue(const MCExpr *Value, unsigned Size) const override;
 };
 }
 
diff --git a/llvm/lib/Target/Mips/MipsTargetObjectFile.cpp b/llvm/lib/Target/Mips/MipsTargetObjectFile.cpp
index fadab780612..c5d6a05d661 100644
--- a/llvm/lib/Target/Mips/MipsTargetObjectFile.cpp
+++ b/llvm/lib/Target/Mips/MipsTargetObjectFile.cpp
@@ -148,3 +148,11 @@ MCSection *MipsTargetObjectFile::getSectionForConstant(const DataLayout &DL,
   // Otherwise, we work the same as ELF.
   return TargetLoweringObjectFileELF::getSectionForConstant(DL, Kind, C, Align);
 }
+
+const MCExpr *
+MipsTargetObjectFile::getDebugThreadLocalSymbol(const MCSymbol *Sym) const {
+  const MCExpr *Expr =
+      MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_None, getContext());
+  return MCBinaryExpr::createAdd(
+      Expr, MCConstantExpr::create(0x8000, getContext()), getContext());
+}
diff --git a/llvm/lib/Target/Mips/MipsTargetObjectFile.h b/llvm/lib/Target/Mips/MipsTargetObjectFile.h
index e5423f9578a..a37ec154ff7 100644
--- a/llvm/lib/Target/Mips/MipsTargetObjectFile.h
+++ b/llvm/lib/Target/Mips/MipsTargetObjectFile.h
@@ -42,6 +42,8 @@ class MipsTargetMachine;
     MCSection *getSectionForConstant(const DataLayout &DL, SectionKind Kind,
                                      const Constant *C,
                                      unsigned &Align) const override;
+    /// Describe a TLS variable address within debug info.
+    const MCExpr *getDebugThreadLocalSymbol(const MCSymbol *Sym) const override;
   };
 } // end namespace llvm