llvm/lib/Target/PowerPC/PPC.h
Ulrich Weigand a68f58ab2b [PowerPC] Always use "assembler dialect" 1
A setting in MCAsmInfo defines the "assembler dialect" to use.  This is used
by common code to choose between alternatives in a multi-alternative GNU
inline asm statement like the following:

  __asm__ ("{sfe|subfe} %0,%1,%2" : "=r" (out) : "r" (in1), "r" (in2));

The meaning of these dialects is platform specific, and GCC defines those
for PowerPC to use dialect 0 for old-style (POWER) mnemonics and 1 for
new-style (PowerPC) mnemonics, like in the example above.

To be compatible with inline asm used with GCC, LLVM ought to do the same.
Specifically, this means we should always use assembler dialect 1 since
old-style mnemonics really aren't supported on any current platform.

However, the current LLVM back-end uses:
  AssemblerDialect = 1;           // New-Style mnemonics.
in PPCMCAsmInfoDarwin, and
  AssemblerDialect = 0;           // Old-Style mnemonics.
in PPCLinuxMCAsmInfo.

The Linux setting really isn't correct, we should be using new-style
mnemonics everywhere.  This is changed by this commit.

Unfortunately, the setting of this variable is overloaded in the back-end
to decide whether or not we are on a Darwin target.  This is done in
PPCInstPrinter (the "SyntaxVariant" is initialized from the MCAsmInfo
AssemblerDialect setting), and also in PPCMCExpr.  Setting AssemblerDialect
to 1 for both Darwin and Linux no longer allows us to make this distinction.

Instead, this patch uses the MCSubtargetInfo passed to createPPCMCInstPrinter
to distinguish Darwin targets, and ignores the SyntaxVariant parameter.
As to PPCMCExpr, this patch adds an explicit isDarwin argument that needs
to be passed in by the caller when creating a target MCExpr.  (To do so
this patch implicitly also reverts commit 184441.)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185858 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-08 20:20:51 +00:00

98 lines
3.1 KiB
C++

//===-- PPC.h - Top-level interface for PowerPC Target ----------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the entry points for global functions defined in the LLVM
// PowerPC back-end.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_TARGET_POWERPC_H
#define LLVM_TARGET_POWERPC_H
#include "MCTargetDesc/PPCMCTargetDesc.h"
#include <string>
// GCC #defines PPC on Linux but we use it as our namespace name
#undef PPC
namespace llvm {
class PPCTargetMachine;
class FunctionPass;
class ImmutablePass;
class JITCodeEmitter;
class MachineInstr;
class AsmPrinter;
class MCInst;
FunctionPass *createPPCCTRLoops(PPCTargetMachine &TM);
#ifndef NDEBUG
FunctionPass *createPPCCTRLoopsVerify();
#endif
FunctionPass *createPPCEarlyReturnPass();
FunctionPass *createPPCBranchSelectionPass();
FunctionPass *createPPCISelDag(PPCTargetMachine &TM);
FunctionPass *createPPCJITCodeEmitterPass(PPCTargetMachine &TM,
JITCodeEmitter &MCE);
void LowerPPCMachineInstrToMCInst(const MachineInstr *MI, MCInst &OutMI,
AsmPrinter &AP, bool isDarwin);
/// \brief Creates an PPC-specific Target Transformation Info pass.
ImmutablePass *createPPCTargetTransformInfoPass(const PPCTargetMachine *TM);
namespace PPCII {
/// Target Operand Flag enum.
enum TOF {
//===------------------------------------------------------------------===//
// PPC Specific MachineOperand flags.
MO_NO_FLAG,
/// MO_DARWIN_STUB - On a symbol operand "FOO", this indicates that the
/// reference is actually to the "FOO$stub" symbol. This is used for calls
/// and jumps to external functions on Tiger and earlier.
MO_DARWIN_STUB = 1,
/// MO_PIC_FLAG - If this bit is set, the symbol reference is relative to
/// the function's picbase, e.g. lo16(symbol-picbase).
MO_PIC_FLAG = 2,
/// MO_NLP_FLAG - If this bit is set, the symbol reference is actually to
/// the non_lazy_ptr for the global, e.g. lo16(symbol$non_lazy_ptr-picbase).
MO_NLP_FLAG = 4,
/// MO_NLP_HIDDEN_FLAG - If this bit is set, the symbol reference is to a
/// symbol with hidden visibility. This causes a different kind of
/// non-lazy-pointer to be generated.
MO_NLP_HIDDEN_FLAG = 8,
/// The next are not flags but distinct values.
MO_ACCESS_MASK = 0xf0,
/// MO_LO, MO_HA - lo16(symbol) and ha16(symbol)
MO_LO = 1 << 4,
MO_HA = 2 << 4,
MO_TPREL_LO = 4 << 4,
MO_TPREL_HA = 3 << 4,
/// These values identify relocations on immediates folded
/// into memory operations.
MO_DTPREL_LO = 5 << 4,
MO_TLSLD_LO = 6 << 4,
MO_TOC_LO = 7 << 4,
// Symbol for VK_PPC_TLS fixup attached to an ADD instruction
MO_TLS = 8 << 4
};
} // end namespace PPCII
} // end namespace llvm;
#endif