Add support for ELF PLT references for ARM MC asm printing. Adding a
new VariantKind to the MCSymbolExpr seems like overkill, but I'm not sure
there's a more straightforward way to get the printing difference captured.
(i.e., x86 uses @PLT, ARM uses (PLT)).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114613 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMBaseInfo.h b/lib/Target/ARM/ARMBaseInfo.h
index a460a5c..2da7be2 100644
--- a/lib/Target/ARM/ARMBaseInfo.h
+++ b/lib/Target/ARM/ARMBaseInfo.h
@@ -181,7 +181,11 @@
/// MO_HI16 - On a symbol operand, this represents a relocation containing
/// higher 16 bit of the address. Used only via movt instruction.
- MO_HI16
+ MO_HI16,
+
+ /// MO_PLT - On a symbol operand, this represents an ELF PLT reference on a
+ /// call operand.
+ MO_PLT
};
} // end namespace ARMII
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index dc68d39..ae1fead 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -1195,8 +1195,14 @@
SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
Callee = DAG.getNode(ARMISD::PIC_ADD, dl,
getPointerTy(), Callee, PICLabel);
- } else
- Callee = DAG.getTargetGlobalAddress(GV, dl, getPointerTy());
+ } else {
+ // On ELF targets for PIC code, direct calls should go through the PLT
+ unsigned OpFlags = 0;
+ if (Subtarget->isTargetELF() &&
+ getTargetMachine().getRelocationModel() == Reloc::PIC_)
+ OpFlags = ARMII::MO_PLT;
+ Callee = DAG.getTargetGlobalAddress(GV, dl, getPointerTy(), 0, OpFlags);
+ }
} else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
isDirect = true;
bool isStub = Subtarget->isTargetDarwin() &&
@@ -1217,8 +1223,14 @@
SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
Callee = DAG.getNode(ARMISD::PIC_ADD, dl,
getPointerTy(), Callee, PICLabel);
- } else
- Callee = DAG.getTargetExternalSymbol(Sym, getPointerTy());
+ } else {
+ unsigned OpFlags = 0;
+ // On ELF targets for PIC code, direct calls should go through the PLT
+ if (Subtarget->isTargetELF() &&
+ getTargetMachine().getRelocationModel() == Reloc::PIC_)
+ OpFlags = ARMII::MO_PLT;
+ Callee = DAG.getTargetExternalSymbol(Sym, getPointerTy(), OpFlags);
+ }
}
// FIXME: handle tail calls differently.
diff --git a/lib/Target/ARM/ARMMCInstLower.cpp b/lib/Target/ARM/ARMMCInstLower.cpp
index ecd289c..e2155f1 100644
--- a/lib/Target/ARM/ARMMCInstLower.cpp
+++ b/lib/Target/ARM/ARMMCInstLower.cpp
@@ -33,7 +33,6 @@
const MCSymbolRefExpr *ARMMCInstLower::
GetSymbolRef(const MachineOperand &MO) const {
assert(MO.isGlobal() && "Isn't a global address reference?");
- // FIXME: HANDLE PLT references how??
const MCSymbolRefExpr *SymRef;
const MCSymbol *Symbol = GetGlobalAddressSymbol(MO.getGlobal());
@@ -49,22 +48,36 @@
case ARMII::MO_HI16:
SymRef = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_ARM_HI16, Ctx);
break;
+ case ARMII::MO_PLT:
+ SymRef = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_ARM_PLT, Ctx);
+ break;
}
return SymRef;
}
-MCSymbol *ARMMCInstLower::
+const MCSymbolRefExpr *ARMMCInstLower::
GetExternalSymbolSymbol(const MachineOperand &MO) const {
- // FIXME: HANDLE PLT references how??
- // FIXME: This probably needs to be merged with the above SymbolRef stuff
- // to handle :lower16: and :upper16: (?)
+ const MCSymbolRefExpr *SymRef;
+ const MCSymbol *Symbol = Printer.GetExternalSymbolSymbol(MO.getSymbolName());
+
switch (MO.getTargetFlags()) {
- default: assert(0 && "Unknown target flag on GV operand");
- case 0: break;
+ default: assert(0 && "Unknown target flag on external symbol operand");
+ case 0:
+ SymRef = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_None, Ctx);
+ break;
+ case ARMII::MO_LO16:
+ SymRef = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_ARM_LO16, Ctx);
+ break;
+ case ARMII::MO_HI16:
+ SymRef = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_ARM_HI16, Ctx);
+ break;
+ case ARMII::MO_PLT:
+ SymRef = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_ARM_PLT, Ctx);
+ break;
}
- return Printer.GetExternalSymbolSymbol(MO.getSymbolName());
+ return SymRef;
}
@@ -157,7 +170,7 @@
MCOp = LowerSymbolRefOperand(MO, GetSymbolRef(MO));
break;
case MachineOperand::MO_ExternalSymbol:
- MCOp = LowerSymbolOperand(MO, GetExternalSymbolSymbol(MO));
+ MCOp = LowerSymbolRefOperand(MO, GetExternalSymbolSymbol(MO));
break;
case MachineOperand::MO_JumpTableIndex:
MCOp = LowerSymbolOperand(MO, GetJumpTableSymbol(MO));
diff --git a/lib/Target/ARM/ARMMCInstLower.h b/lib/Target/ARM/ARMMCInstLower.h
index 79ed2e9..c4d27f8 100644
--- a/lib/Target/ARM/ARMMCInstLower.h
+++ b/lib/Target/ARM/ARMMCInstLower.h
@@ -43,7 +43,8 @@
//MCSymbol *GetPICBaseSymbol() const;
MCSymbol *GetGlobalAddressSymbol(const GlobalValue *GV) const;
const MCSymbolRefExpr *GetSymbolRef(const MachineOperand &MO) const;
- MCSymbol *GetExternalSymbolSymbol(const MachineOperand &MO) const;
+ const MCSymbolRefExpr *GetExternalSymbolSymbol(const MachineOperand &MO)
+ const;
MCSymbol *GetJumpTableSymbol(const MachineOperand &MO) const;
MCSymbol *GetConstantPoolIndexSymbol(const MachineOperand &MO) const;
MCOperand LowerSymbolRefOperand(const MachineOperand &MO,