[SystemZ] Support all TLS access models - MC part

The current SystemZ back-end only supports the local-exec TLS access model.
This patch adds all required MC support for the other TLS models, which
means in particular:

- Support additional relocation types for
  Initial-exec model: R_390_TLS_IEENT
  Local-dynamic-model: R_390_TLS_LDO32, R_390_TLS_LDO64,
                       R_390_TLS_LDM32, R_390_TLS_LDM64, R_390_TLS_LDCALL
  General-dynamic model: R_390_TLS_GD32, R_390_TLS_GD64, R_390_TLS_GDCALL

- Support assembler syntax to generate additional relocations
  for use with __tls_get_offset calls:
    :tls_gdcall:
    :tls_ldcall:

The patch also adds a new test to verify fixups and relocations,
and removes the (already unused) FK_390_PLT16DBL/FK_390_PLT32DBL
fixup kinds.

llvm-svn: 229652

1 files changed, 46 insertions, 2 deletions

diff --git a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCObjectWriter.cpp b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCObjectWriter.cpp
index c6a18165889..263251800d7 100644
--- a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCObjectWriter.cpp
+++ b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCObjectWriter.cpp
@@ -55,8 +55,6 @@ static unsigned getPCRelReloc(unsigned Kind) {
   case FK_Data_8:                return ELF::R_390_PC64;
   case SystemZ::FK_390_PC16DBL:  return ELF::R_390_PC16DBL;
   case SystemZ::FK_390_PC32DBL:  return ELF::R_390_PC32DBL;
-  case SystemZ::FK_390_PLT16DBL: return ELF::R_390_PLT16DBL;
-  case SystemZ::FK_390_PLT32DBL: return ELF::R_390_PLT32DBL;
   }
   llvm_unreachable("Unsupported PC-relative address");
 }
@@ -70,6 +68,35 @@ static unsigned getTLSLEReloc(unsigned Kind) {
   llvm_unreachable("Unsupported absolute address");
 }
 
+// Return the R_390_TLS_LDO* relocation type for MCFixupKind Kind.
+static unsigned getTLSLDOReloc(unsigned Kind) {
+  switch (Kind) {
+  case FK_Data_4: return ELF::R_390_TLS_LDO32;
+  case FK_Data_8: return ELF::R_390_TLS_LDO64;
+  }
+  llvm_unreachable("Unsupported absolute address");
+}
+
+// Return the R_390_TLS_LDM* relocation type for MCFixupKind Kind.
+static unsigned getTLSLDMReloc(unsigned Kind) {
+  switch (Kind) {
+  case FK_Data_4: return ELF::R_390_TLS_LDM32;
+  case FK_Data_8: return ELF::R_390_TLS_LDM64;
+  case SystemZ::FK_390_TLS_CALL: return ELF::R_390_TLS_LDCALL;
+  }
+  llvm_unreachable("Unsupported absolute address");
+}
+
+// Return the R_390_TLS_GD* relocation type for MCFixupKind Kind.
+static unsigned getTLSGDReloc(unsigned Kind) {
+  switch (Kind) {
+  case FK_Data_4: return ELF::R_390_TLS_GD32;
+  case FK_Data_8: return ELF::R_390_TLS_GD64;
+  case SystemZ::FK_390_TLS_CALL: return ELF::R_390_TLS_GDCALL;
+  }
+  llvm_unreachable("Unsupported absolute address");
+}
+
 // Return the PLT relocation counterpart of MCFixupKind Kind.
 static unsigned getPLTReloc(unsigned Kind) {
   switch (Kind) {
@@ -94,6 +121,23 @@ unsigned SystemZObjectWriter::GetRelocType(const MCValue &Target,
     assert(!IsPCRel && "NTPOFF shouldn't be PC-relative");
     return getTLSLEReloc(Kind);
 
+  case MCSymbolRefExpr::VK_INDNTPOFF:
+    if (IsPCRel && Kind == SystemZ::FK_390_PC32DBL)
+      return ELF::R_390_TLS_IEENT;
+    llvm_unreachable("Only PC-relative INDNTPOFF accesses are supported for now");
+
+  case MCSymbolRefExpr::VK_DTPOFF:
+    assert(!IsPCRel && "DTPOFF shouldn't be PC-relative");
+    return getTLSLDOReloc(Kind);
+
+  case MCSymbolRefExpr::VK_TLSLDM:
+    assert(!IsPCRel && "TLSLDM shouldn't be PC-relative");
+    return getTLSLDMReloc(Kind);
+
+  case MCSymbolRefExpr::VK_TLSGD:
+    assert(!IsPCRel && "TLSGD shouldn't be PC-relative");
+    return getTLSGDReloc(Kind);
+
   case MCSymbolRefExpr::VK_GOT:
     if (IsPCRel && Kind == SystemZ::FK_390_PC32DBL)
       return ELF::R_390_GOTENT;