llvm/lib/Target/PowerPC/PPCTLSDynamicCall.cpp
2015-02-04 06:14:38 +00:00

114 lines
3.6 KiB
C++

//===---------- PPCTLSDynamicCall.cpp - TLS Dynamic Call Fixup ------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This pass fixes up GETtls[ld]ADDR[32] machine instructions so that
// they read and write GPR3. These are really call instructions, so
// must use the calling convention registers. This is done in a late
// pass so that TLS variable accesses can be fully commoned.
//
//===----------------------------------------------------------------------===//
#include "PPCInstrInfo.h"
#include "PPC.h"
#include "PPCInstrBuilder.h"
#include "PPCTargetMachine.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
#define DEBUG_TYPE "ppc-tls-dynamic-call"
namespace llvm {
void initializePPCTLSDynamicCallPass(PassRegistry&);
}
namespace {
// PPCTLSDynamicCall pass - Add copies to and from GPR3 around
// GETtls[ld]ADDR[32] machine instructions. These instructions
// are actually call instructions, so the register choice is
// constrained. We delay introducing these copies as late as
// possible so that TLS variable accesses can be fully commoned.
struct PPCTLSDynamicCall : public MachineFunctionPass {
static char ID;
PPCTLSDynamicCall() : MachineFunctionPass(ID) {
initializePPCTLSDynamicCallPass(*PassRegistry::getPassRegistry());
}
const PPCTargetMachine *TM;
const PPCInstrInfo *TII;
protected:
bool processBlock(MachineBasicBlock &MBB) {
bool Changed = false;
bool Is64Bit = TM->getSubtargetImpl()->isPPC64();
for (MachineBasicBlock::iterator I = MBB.begin(), IE = MBB.end();
I != IE; ++I) {
MachineInstr *MI = I;
if (MI->getOpcode() != PPC::GETtlsADDR &&
MI->getOpcode() != PPC::GETtlsldADDR &&
MI->getOpcode() != PPC::GETtlsADDR32 &&
MI->getOpcode() != PPC::GETtlsldADDR32)
continue;
DEBUG(dbgs() << "TLS Dynamic Call Fixup:\n " << *MI;);
unsigned OutReg = MI->getOperand(0).getReg();
unsigned InReg = MI->getOperand(1).getReg();
DebugLoc DL = MI->getDebugLoc();
unsigned GPR3 = Is64Bit ? PPC::X3 : PPC::R3;
BuildMI(MBB, I, DL, TII->get(TargetOpcode::COPY), GPR3)
.addReg(InReg);
MI->getOperand(0).setReg(GPR3);
MI->getOperand(1).setReg(GPR3);
BuildMI(MBB, ++I, DL, TII->get(TargetOpcode::COPY), OutReg)
.addReg(GPR3);
Changed = true;
}
return Changed;
}
public:
bool runOnMachineFunction(MachineFunction &MF) override {
TM = static_cast<const PPCTargetMachine *>(&MF.getTarget());
TII = TM->getSubtargetImpl()->getInstrInfo();
bool Changed = false;
for (MachineFunction::iterator I = MF.begin(); I != MF.end();) {
MachineBasicBlock &B = *I++;
if (processBlock(B))
Changed = true;
}
return Changed;
}
void getAnalysisUsage(AnalysisUsage &AU) const override {
MachineFunctionPass::getAnalysisUsage(AU);
}
};
}
INITIALIZE_PASS_BEGIN(PPCTLSDynamicCall, DEBUG_TYPE,
"PowerPC TLS Dynamic Call Fixup", false, false)
INITIALIZE_PASS_END(PPCTLSDynamicCall, DEBUG_TYPE,
"PowerPC TLS Dynamic Call Fixup", false, false)
char PPCTLSDynamicCall::ID = 0;
FunctionPass*
llvm::createPPCTLSDynamicCallPass() { return new PPCTLSDynamicCall(); }