Handle _GLOBAL_OFFSET_TABLE_ in 64 bit mode.

With this MC is able to handle _GLOBAL_OFFSET_TABLE_ in 64 bit mode, which is
needed for medium and large code models.

This fixes pr19470.

llvm-svn: 206793

4 files changed, 15 insertions, 1 deletions

diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
index cfe8918574f..bf30a8e6663 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
@@ -58,6 +58,7 @@ static unsigned getFixupKindLog2Size(unsigned Kind) {
   case FK_PCRel_8:
   case FK_SecRel_8:
   case FK_Data_8:
+  case X86::reloc_global_offset_table8:
     return 3;
   }
 }
diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86ELFObjectWriter.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86ELFObjectWriter.cpp
index c44d88d48b6..c4a1af86157 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86ELFObjectWriter.cpp
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86ELFObjectWriter.cpp
@@ -98,6 +98,12 @@ unsigned X86ELFObjectWriter::GetRelocType(const MCValue &Target,
     } else {
       switch ((unsigned)Fixup.getKind()) {
       default: llvm_unreachable("invalid fixup kind!");
+      case X86::reloc_global_offset_table8:
+        Type = ELF::R_X86_64_GOTPC64;
+        break;
+      case X86::reloc_global_offset_table:
+        Type = ELF::R_X86_64_GOTPC32;
+        break;
       case FK_Data_8:
         switch (Modifier) {
         default:
diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86FixupKinds.h b/llvm/lib/Target/X86/MCTargetDesc/X86FixupKinds.h
index f2e34cbe0d6..09396b790df 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86FixupKinds.h
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86FixupKinds.h
@@ -23,6 +23,7 @@ enum Fixups {
   reloc_global_offset_table,                 // 32-bit, relative to the start
                                              // of the instruction. Used only
                                              // for _GLOBAL_OFFSET_TABLE_.
+  reloc_global_offset_table8,                // 64-bit variant.
   // Marker
   LastTargetFixupKind,
   NumTargetFixupKinds = LastTargetFixupKind - FirstTargetFixupKind
diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
index e6fb0377f00..4dcb6fd9188 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
@@ -339,7 +339,13 @@ EmitImmediate(const MCOperand &DispOp, SMLoc Loc, unsigned Size,
     if (Kind != GOT_None) {
       assert(ImmOffset == 0);
 
-      FixupKind = MCFixupKind(X86::reloc_global_offset_table);
+      if (Size == 8) {
+        FixupKind = MCFixupKind(X86::reloc_global_offset_table8);
+      } else {
+        assert(Size == 4);
+        FixupKind = MCFixupKind(X86::reloc_global_offset_table);
+      }
+
       if (Kind == GOT_Normal)
         ImmOffset = CurByte;
     } else if (Expr->getKind() == MCExpr::SymbolRef) {