Delete the allocated vector.

[oota-llvm.git] / lib / Target / X86 / X86MCCodeEmitter.cpp

diff --git a/lib/Target/X86/X86MCCodeEmitter.cpp b/lib/Target/X86/X86MCCodeEmitter.cpp
index d5cab49c0d6afa3a162b351af734363037ada463..950fdf107a2c11be894fe6c8a5ad74e88cb465a0 100644 (file)
--- a/lib/Target/X86/X86MCCodeEmitter.cpp
+++ b/lib/Target/X86/X86MCCodeEmitter.cpp
@@ -18,6 +18,7 @@
 #include "llvm/MC/MCCodeEmitter.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCSymbol.h"
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
@@ -38,7 +39,7 @@ public:
   ~X86MCCodeEmitter() {}
 
   unsigned getNumFixupKinds() const {
-    return 6;
+    return 7;
   }
 
   const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const {
@@ -48,7 +49,8 @@ public:
       { "reloc_pcrel_2byte", 0, 2 * 8, MCFixupKindInfo::FKF_IsPCRel },
       { "reloc_riprel_4byte", 0, 4 * 8, MCFixupKindInfo::FKF_IsPCRel },
       { "reloc_riprel_4byte_movq_load", 0, 4 * 8, MCFixupKindInfo::FKF_IsPCRel },
-      { "reloc_signed_4byte", 0, 4 * 8, 0}
+      { "reloc_signed_4byte", 0, 4 * 8, 0},
+      { "reloc_global_offset_table", 0, 4 * 8, 0}
     };
 
     if (Kind < FirstTargetFixupKind)
@@ -193,6 +195,25 @@ static bool Is32BitMemOperand(const MCInst &MI, unsigned Op) {
   return false;
 }
 
+/// StartsWithGlobalOffsetTable - Return true for the simple cases where this
+/// expression starts with _GLOBAL_OFFSET_TABLE_. This is a needed to support
+/// PIC on ELF i386 as that symbol is magic. We check only simple case that
+/// are know to be used: _GLOBAL_OFFSET_TABLE_ by itself or at the start
+/// of a binary expression.
+static bool StartsWithGlobalOffsetTable(const MCExpr *Expr) {
+  if (Expr->getKind() == MCExpr::Binary) {
+    const MCBinaryExpr *BE = static_cast<const MCBinaryExpr *>(Expr);
+    Expr = BE->getLHS();
+  }
+
+  if (Expr->getKind() != MCExpr::SymbolRef)
+    return false;
+
+  const MCSymbolRefExpr *Ref = static_cast<const MCSymbolRefExpr*>(Expr);
+  const MCSymbol &S = Ref->getSymbol();
+  return S.getName() == "_GLOBAL_OFFSET_TABLE_";
+}
+
 void X86MCCodeEmitter::
 EmitImmediate(const MCOperand &DispOp, unsigned Size, MCFixupKind FixupKind,
               unsigned &CurByte, raw_ostream &OS,
@@ -209,6 +230,13 @@ EmitImmediate(const MCOperand &DispOp, unsigned Size, MCFixupKind FixupKind,
   // If we have an immoffset, add it to the expression.
   const MCExpr *Expr = DispOp.getExpr();
 
+  if (FixupKind == FK_Data_4 && StartsWithGlobalOffsetTable(Expr)) {
+    assert(ImmOffset == 0);
+
+    FixupKind = MCFixupKind(X86::reloc_global_offset_table);
+    ImmOffset = CurByte;
+  }
+
   // If the fixup is pc-relative, we need to bias the value to be relative to
   // the start of the field, not the end of the field.
   if (FixupKind == MCFixupKind(X86::reloc_pcrel_4byte) ||
@@ -251,8 +279,7 @@ void X86MCCodeEmitter::EmitMemModRMByte(const MCInst &MI, unsigned Op,
     // movq loads are handled with a special relocation form which allows the
     // linker to eliminate some loads for GOT references which end up in the
     // same linkage unit.
-    if (MI.getOpcode() == X86::MOV64rm ||
-        MI.getOpcode() == X86::MOV64rm_TC)
+    if (MI.getOpcode() == X86::MOV64rm)
       FixupKind = X86::reloc_riprel_4byte_movq_load;
 
     // rip-relative addressing is actually relative to the *next* instruction.