llvm/lib/Target/ARM/ARMMCInstLower.cpp
David Peixotto 0fc8c68b11 Add support for parsing ARM symbol variants on ELF targets
ARM symbol variants are written with parens instead of @ like this:

  .word __GLOBAL_I_a(target1)

This commit adds support for parsing these symbol variants in
expressions. We introduce a new flag to MCAsmInfo that indicates the
parser should use parens to parse the symbol variant. The expression
parser is modified to look for symbol variants using parens instead
of @ when the corresponding MCAsmInfo flag is true.

The MCAsmInfo parens flag is enabled only for ARM on ELF.

By adding this flag to MCAsmInfo, we are able to get rid of
redundant ARM-specific symbol variants and use the generic variants
instead (e.g. VK_GOT instead of VK_ARM_GOT). We use the new
UseParensForSymbolVariant attribute in MCAsmInfo to correctly print
the symbol variants for arm.

To achive this we need to keep a handle to the MCAsmInfo in the
MCSymbolRefExpr class that we can check when printing the symbol
variant.

Updated Tests:
  Changed case of symbol variant to match the generic kind.
  test/CodeGen/ARM/tls-models.ll
  test/CodeGen/ARM/tls1.ll
  test/CodeGen/ARM/tls2.ll
  test/CodeGen/Thumb2/tls1.ll
  test/CodeGen/Thumb2/tls2.ll

PR18080


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196424 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-04 22:43:20 +00:00

129 lines
4.2 KiB
C++

//===-- ARMMCInstLower.cpp - Convert ARM MachineInstr to an MCInst --------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains code to lower ARM MachineInstrs to their corresponding
// MCInst records.
//
//===----------------------------------------------------------------------===//
#include "ARM.h"
#include "ARMAsmPrinter.h"
#include "MCTargetDesc/ARMMCExpr.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/IR/Constants.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/Target/Mangler.h"
using namespace llvm;
MCOperand ARMAsmPrinter::GetSymbolRef(const MachineOperand &MO,
const MCSymbol *Symbol) {
const MCExpr *Expr;
unsigned Option = MO.getTargetFlags() & ARMII::MO_OPTION_MASK;
switch (Option) {
default: {
Expr = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_None,
OutContext);
switch (Option) {
default: llvm_unreachable("Unknown target flag on symbol operand");
case 0:
break;
case ARMII::MO_LO16:
Expr = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_None,
OutContext);
Expr = ARMMCExpr::CreateLower16(Expr, OutContext);
break;
case ARMII::MO_HI16:
Expr = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_None,
OutContext);
Expr = ARMMCExpr::CreateUpper16(Expr, OutContext);
break;
}
break;
}
case ARMII::MO_PLT:
Expr = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_PLT,
OutContext);
break;
}
if (!MO.isJTI() && MO.getOffset())
Expr = MCBinaryExpr::CreateAdd(Expr,
MCConstantExpr::Create(MO.getOffset(),
OutContext),
OutContext);
return MCOperand::CreateExpr(Expr);
}
bool ARMAsmPrinter::lowerOperand(const MachineOperand &MO,
MCOperand &MCOp) {
switch (MO.getType()) {
default: llvm_unreachable("unknown operand type");
case MachineOperand::MO_Register:
// Ignore all non-CPSR implicit register operands.
if (MO.isImplicit() && MO.getReg() != ARM::CPSR)
return false;
assert(!MO.getSubReg() && "Subregs should be eliminated!");
MCOp = MCOperand::CreateReg(MO.getReg());
break;
case MachineOperand::MO_Immediate:
MCOp = MCOperand::CreateImm(MO.getImm());
break;
case MachineOperand::MO_MachineBasicBlock:
MCOp = MCOperand::CreateExpr(MCSymbolRefExpr::Create(
MO.getMBB()->getSymbol(), OutContext));
break;
case MachineOperand::MO_GlobalAddress: {
MCOp = GetSymbolRef(MO,
GetARMGVSymbol(MO.getGlobal(), MO.getTargetFlags()));
break;
}
case MachineOperand::MO_ExternalSymbol:
MCOp = GetSymbolRef(MO,
GetExternalSymbolSymbol(MO.getSymbolName()));
break;
case MachineOperand::MO_JumpTableIndex:
MCOp = GetSymbolRef(MO, GetJTISymbol(MO.getIndex()));
break;
case MachineOperand::MO_ConstantPoolIndex:
MCOp = GetSymbolRef(MO, GetCPISymbol(MO.getIndex()));
break;
case MachineOperand::MO_BlockAddress:
MCOp = GetSymbolRef(MO, GetBlockAddressSymbol(MO.getBlockAddress()));
break;
case MachineOperand::MO_FPImmediate: {
APFloat Val = MO.getFPImm()->getValueAPF();
bool ignored;
Val.convert(APFloat::IEEEdouble, APFloat::rmTowardZero, &ignored);
MCOp = MCOperand::CreateFPImm(Val.convertToDouble());
break;
}
case MachineOperand::MO_RegisterMask:
// Ignore call clobbers.
return false;
}
return true;
}
void llvm::LowerARMMachineInstrToMCInst(const MachineInstr *MI, MCInst &OutMI,
ARMAsmPrinter &AP) {
OutMI.setOpcode(MI->getOpcode());
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
MCOperand MCOp;
if (AP.lowerOperand(MO, MCOp))
OutMI.addOperand(MCOp);
}
}