llvm-6502/lib/Target/PowerPC/PPCCodeEmitter.cpp
Bill Schmidt d7802bf0dd This patch introduces initial-exec model support for thread-local storage
on 64-bit PowerPC ELF.

The patch includes code to handle external assembly and MC output with the
integrated assembler.  It intentionally does not support the "old" JIT.

For the initial-exec TLS model, the ABI requires the following to calculate
the address of external thread-local variable x:

 Code sequence            Relocation                  Symbol
  ld 9,x@got@tprel(2)      R_PPC64_GOT_TPREL16_DS      x
  add 9,9,x@tls            R_PPC64_TLS                 x

The register 9 is arbitrary here.  The linker will replace x@got@tprel
with the offset relative to the thread pointer to the generated GOT
entry for symbol x.  It will replace x@tls with the thread-pointer
register (13).

The two test cases verify correct assembly output and relocation output
as just described.

PowerPC-specific selection node variants are added for the two
instructions above:  LD_GOT_TPREL and ADD_TLS.  These are inserted
when an initial-exec global variable is encountered by
PPCTargetLowering::LowerGlobalTLSAddress(), and later lowered to
machine instructions LDgotTPREL and ADD8TLS.  LDgotTPREL is a pseudo
that uses the same LDrs support added for medium code model's LDtocL,
with a different relocation type.

The rest of the processing is straightforward.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169281 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-04 16:18:08 +00:00

280 lines
10 KiB
C++

//===-- PPCCodeEmitter.cpp - JIT Code Emitter for PowerPC -----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the PowerPC 32-bit CodeEmitter and associated machinery to
// JIT-compile bitcode to native PowerPC.
//
//===----------------------------------------------------------------------===//
#include "PPC.h"
#include "PPCRelocations.h"
#include "PPCTargetMachine.h"
#include "llvm/CodeGen/JITCodeEmitter.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/Module.h"
#include "llvm/PassManager.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
namespace {
class PPCCodeEmitter : public MachineFunctionPass {
TargetMachine &TM;
JITCodeEmitter &MCE;
MachineModuleInfo *MMI;
void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<MachineModuleInfo>();
MachineFunctionPass::getAnalysisUsage(AU);
}
static char ID;
/// MovePCtoLROffset - When/if we see a MovePCtoLR instruction, we record
/// its address in the function into this pointer.
void *MovePCtoLROffset;
public:
PPCCodeEmitter(TargetMachine &tm, JITCodeEmitter &mce)
: MachineFunctionPass(ID), TM(tm), MCE(mce) {}
/// getBinaryCodeForInstr - This function, generated by the
/// CodeEmitterGenerator using TableGen, produces the binary encoding for
/// machine instructions.
uint64_t getBinaryCodeForInstr(const MachineInstr &MI) const;
MachineRelocation GetRelocation(const MachineOperand &MO,
unsigned RelocID) const;
/// getMachineOpValue - evaluates the MachineOperand of a given MachineInstr
unsigned getMachineOpValue(const MachineInstr &MI,
const MachineOperand &MO) const;
unsigned get_crbitm_encoding(const MachineInstr &MI, unsigned OpNo) const;
unsigned getDirectBrEncoding(const MachineInstr &MI, unsigned OpNo) const;
unsigned getCondBrEncoding(const MachineInstr &MI, unsigned OpNo) const;
unsigned getHA16Encoding(const MachineInstr &MI, unsigned OpNo) const;
unsigned getLO16Encoding(const MachineInstr &MI, unsigned OpNo) const;
unsigned getMemRIEncoding(const MachineInstr &MI, unsigned OpNo) const;
unsigned getMemRIXEncoding(const MachineInstr &MI, unsigned OpNo) const;
unsigned getTLSOffsetEncoding(const MachineInstr &MI, unsigned OpNo) const;
unsigned getTLSRegEncoding(const MachineInstr &MI, unsigned OpNo) const;
const char *getPassName() const { return "PowerPC Machine Code Emitter"; }
/// runOnMachineFunction - emits the given MachineFunction to memory
///
bool runOnMachineFunction(MachineFunction &MF);
/// emitBasicBlock - emits the given MachineBasicBlock to memory
///
void emitBasicBlock(MachineBasicBlock &MBB);
};
}
char PPCCodeEmitter::ID = 0;
/// createPPCCodeEmitterPass - Return a pass that emits the collected PPC code
/// to the specified MCE object.
FunctionPass *llvm::createPPCJITCodeEmitterPass(PPCTargetMachine &TM,
JITCodeEmitter &JCE) {
return new PPCCodeEmitter(TM, JCE);
}
bool PPCCodeEmitter::runOnMachineFunction(MachineFunction &MF) {
assert((MF.getTarget().getRelocationModel() != Reloc::Default ||
MF.getTarget().getRelocationModel() != Reloc::Static) &&
"JIT relocation model must be set to static or default!");
MMI = &getAnalysis<MachineModuleInfo>();
MCE.setModuleInfo(MMI);
do {
MovePCtoLROffset = 0;
MCE.startFunction(MF);
for (MachineFunction::iterator BB = MF.begin(), E = MF.end(); BB != E; ++BB)
emitBasicBlock(*BB);
} while (MCE.finishFunction(MF));
return false;
}
void PPCCodeEmitter::emitBasicBlock(MachineBasicBlock &MBB) {
MCE.StartMachineBasicBlock(&MBB);
for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); I != E; ++I){
const MachineInstr &MI = *I;
MCE.processDebugLoc(MI.getDebugLoc(), true);
switch (MI.getOpcode()) {
default:
MCE.emitWordBE(getBinaryCodeForInstr(MI));
break;
case TargetOpcode::PROLOG_LABEL:
case TargetOpcode::EH_LABEL:
MCE.emitLabel(MI.getOperand(0).getMCSymbol());
break;
case TargetOpcode::IMPLICIT_DEF:
case TargetOpcode::KILL:
break; // pseudo opcode, no side effects
case PPC::MovePCtoLR:
case PPC::MovePCtoLR8:
assert(TM.getRelocationModel() == Reloc::PIC_);
MovePCtoLROffset = (void*)MCE.getCurrentPCValue();
MCE.emitWordBE(0x48000005); // bl 1
break;
}
MCE.processDebugLoc(MI.getDebugLoc(), false);
}
}
unsigned PPCCodeEmitter::get_crbitm_encoding(const MachineInstr &MI,
unsigned OpNo) const {
const MachineOperand &MO = MI.getOperand(OpNo);
assert((MI.getOpcode() == PPC::MTCRF || MI.getOpcode() == PPC::MTCRF8 ||
MI.getOpcode() == PPC::MFOCRF) &&
(MO.getReg() >= PPC::CR0 && MO.getReg() <= PPC::CR7));
return 0x80 >> getPPCRegisterNumbering(MO.getReg());
}
MachineRelocation PPCCodeEmitter::GetRelocation(const MachineOperand &MO,
unsigned RelocID) const {
// If in PIC mode, we need to encode the negated address of the
// 'movepctolr' into the unrelocated field. After relocation, we'll have
// &gv-&movepctolr-4 in the imm field. Once &movepctolr is added to the imm
// field, we get &gv. This doesn't happen for branch relocations, which are
// always implicitly pc relative.
intptr_t Cst = 0;
if (TM.getRelocationModel() == Reloc::PIC_) {
assert(MovePCtoLROffset && "MovePCtoLR not seen yet?");
Cst = -(intptr_t)MovePCtoLROffset - 4;
}
if (MO.isGlobal())
return MachineRelocation::getGV(MCE.getCurrentPCOffset(), RelocID,
const_cast<GlobalValue *>(MO.getGlobal()),
Cst, isa<Function>(MO.getGlobal()));
if (MO.isSymbol())
return MachineRelocation::getExtSym(MCE.getCurrentPCOffset(),
RelocID, MO.getSymbolName(), Cst);
if (MO.isCPI())
return MachineRelocation::getConstPool(MCE.getCurrentPCOffset(),
RelocID, MO.getIndex(), Cst);
if (MO.isMBB())
return MachineRelocation::getBB(MCE.getCurrentPCOffset(),
RelocID, MO.getMBB());
assert(MO.isJTI());
return MachineRelocation::getJumpTable(MCE.getCurrentPCOffset(),
RelocID, MO.getIndex(), Cst);
}
unsigned PPCCodeEmitter::getDirectBrEncoding(const MachineInstr &MI,
unsigned OpNo) const {
const MachineOperand &MO = MI.getOperand(OpNo);
if (MO.isReg() || MO.isImm()) return getMachineOpValue(MI, MO);
MCE.addRelocation(GetRelocation(MO, PPC::reloc_pcrel_bx));
return 0;
}
unsigned PPCCodeEmitter::getCondBrEncoding(const MachineInstr &MI,
unsigned OpNo) const {
const MachineOperand &MO = MI.getOperand(OpNo);
MCE.addRelocation(GetRelocation(MO, PPC::reloc_pcrel_bcx));
return 0;
}
unsigned PPCCodeEmitter::getHA16Encoding(const MachineInstr &MI,
unsigned OpNo) const {
const MachineOperand &MO = MI.getOperand(OpNo);
if (MO.isReg() || MO.isImm()) return getMachineOpValue(MI, MO);
MCE.addRelocation(GetRelocation(MO, PPC::reloc_absolute_high));
return 0;
}
unsigned PPCCodeEmitter::getLO16Encoding(const MachineInstr &MI,
unsigned OpNo) const {
const MachineOperand &MO = MI.getOperand(OpNo);
if (MO.isReg() || MO.isImm()) return getMachineOpValue(MI, MO);
MCE.addRelocation(GetRelocation(MO, PPC::reloc_absolute_low));
return 0;
}
unsigned PPCCodeEmitter::getMemRIEncoding(const MachineInstr &MI,
unsigned OpNo) const {
// Encode (imm, reg) as a memri, which has the low 16-bits as the
// displacement and the next 5 bits as the register #.
assert(MI.getOperand(OpNo+1).isReg());
unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo+1)) << 16;
const MachineOperand &MO = MI.getOperand(OpNo);
if (MO.isImm())
return (getMachineOpValue(MI, MO) & 0xFFFF) | RegBits;
// Add a fixup for the displacement field.
MCE.addRelocation(GetRelocation(MO, PPC::reloc_absolute_low));
return RegBits;
}
unsigned PPCCodeEmitter::getMemRIXEncoding(const MachineInstr &MI,
unsigned OpNo) const {
// Encode (imm, reg) as a memrix, which has the low 14-bits as the
// displacement and the next 5 bits as the register #.
assert(MI.getOperand(OpNo+1).isReg());
unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo+1)) << 14;
const MachineOperand &MO = MI.getOperand(OpNo);
if (MO.isImm())
return (getMachineOpValue(MI, MO) & 0x3FFF) | RegBits;
MCE.addRelocation(GetRelocation(MO, PPC::reloc_absolute_low_ix));
return RegBits;
}
unsigned PPCCodeEmitter::getTLSOffsetEncoding(const MachineInstr &MI,
unsigned OpNo) const {
llvm_unreachable("TLS not supported on the old JIT.");
return 0;
}
unsigned PPCCodeEmitter::getTLSRegEncoding(const MachineInstr &MI,
unsigned OpNo) const {
llvm_unreachable("TLS not supported on the old JIT.");
return 0;
}
unsigned PPCCodeEmitter::getMachineOpValue(const MachineInstr &MI,
const MachineOperand &MO) const {
if (MO.isReg()) {
// MTCRF/MFOCRF should go through get_crbitm_encoding for the CR operand.
// The GPR operand should come through here though.
assert((MI.getOpcode() != PPC::MTCRF && MI.getOpcode() != PPC::MTCRF8 &&
MI.getOpcode() != PPC::MFOCRF) ||
MO.getReg() < PPC::CR0 || MO.getReg() > PPC::CR7);
return getPPCRegisterNumbering(MO.getReg());
}
assert(MO.isImm() &&
"Relocation required in an instruction that we cannot encode!");
return MO.getImm();
}
#include "PPCGenCodeEmitter.inc"