From 8f50647662560167b88851f92c3c891d2e7c1696 Mon Sep 17 00:00:00 2001 From: Jush Lu Date: Thu, 27 Sep 2012 05:21:41 +0000 Subject: [PATCH] [arm-fast-isel] Add support for ELF PIC. This is a preliminary step towards ELF support; currently ARMFastISel hasn't been used for ELF object files yet. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164759 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/ARM/ARM.h | 1 + lib/Target/ARM/ARMFastISel.cpp | 45 ++++++++++++++++++ lib/Target/ARM/ARMInstrInfo.cpp | 62 +++++++++++++++++++++++++ lib/Target/ARM/ARMMachineFunctionInfo.h | 12 ++++- lib/Target/ARM/ARMTargetMachine.cpp | 5 ++ test/CodeGen/ARM/fast-isel-pic.ll | 18 +++++++ 6 files changed, 141 insertions(+), 2 deletions(-) diff --git a/lib/Target/ARM/ARM.h b/lib/Target/ARM/ARM.h index 2a1e8e4d307..1446bbbb8e7 100644 --- a/lib/Target/ARM/ARM.h +++ b/lib/Target/ARM/ARM.h @@ -37,6 +37,7 @@ FunctionPass *createARMJITCodeEmitterPass(ARMBaseTargetMachine &TM, FunctionPass *createARMLoadStoreOptimizationPass(bool PreAlloc = false); FunctionPass *createARMExpandPseudoPass(); +FunctionPass *createARMGlobalBaseRegPass(); FunctionPass *createARMGlobalMergePass(const TargetLowering* tli); FunctionPass *createARMConstantIslandPass(); FunctionPass *createMLxExpansionPass(); diff --git a/lib/Target/ARM/ARMFastISel.cpp b/lib/Target/ARM/ARMFastISel.cpp index f7f6b5dbb1c..8933a02701c 100644 --- a/lib/Target/ARM/ARMFastISel.cpp +++ b/lib/Target/ARM/ARMFastISel.cpp @@ -194,6 +194,7 @@ class ARMFastISel : public FastISel { unsigned ARMMoveToFPReg(EVT VT, unsigned SrcReg); unsigned ARMMoveToIntReg(EVT VT, unsigned SrcReg); unsigned ARMSelectCallOp(bool UseReg); + unsigned ARMLowerPICELF(const GlobalValue *GV, unsigned Align, EVT VT); // Call handling routines. private: @@ -648,6 +649,9 @@ unsigned ARMFastISel::ARMMaterializeGV(const GlobalValue *GV, EVT VT) { Align = TD.getTypeAllocSize(GV->getType()); } + if (Subtarget->isTargetELF() && RelocM == Reloc::PIC_) + return ARMLowerPICELF(GV, Align, VT); + // Grab index. unsigned PCAdj = (RelocM != Reloc::PIC_) ? 0 : (Subtarget->isThumb() ? 4 : 8); @@ -2796,6 +2800,47 @@ bool ARMFastISel::TryToFoldLoad(MachineInstr *MI, unsigned OpNo, return true; } +unsigned ARMFastISel::ARMLowerPICELF(const GlobalValue *GV, + unsigned Align, EVT VT) { + bool UseGOTOFF = GV->hasLocalLinkage() || GV->hasHiddenVisibility(); + ARMConstantPoolConstant *CPV = + ARMConstantPoolConstant::Create(GV, UseGOTOFF ? ARMCP::GOTOFF : ARMCP::GOT); + unsigned Idx = MCP.getConstantPoolIndex(CPV, Align); + + unsigned Opc; + unsigned DestReg1 = createResultReg(TLI.getRegClassFor(VT)); + // Load value. + if (isThumb2) { + AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, + TII.get(ARM::t2LDRpci), DestReg1) + .addConstantPoolIndex(Idx)); + Opc = UseGOTOFF ? ARM::t2ADDrr : ARM::t2LDRs; + } else { + // The extra immediate is for addrmode2. + AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, + DL, TII.get(ARM::LDRcp), DestReg1) + .addConstantPoolIndex(Idx).addImm(0)); + Opc = UseGOTOFF ? ARM::ADDrr : ARM::LDRrs; + } + + unsigned GlobalBaseReg = AFI->getGlobalBaseReg(); + if (GlobalBaseReg == 0) { + GlobalBaseReg = MRI.createVirtualRegister(TLI.getRegClassFor(VT)); + AFI->setGlobalBaseReg(GlobalBaseReg); + } + + unsigned DestReg2 = createResultReg(TLI.getRegClassFor(VT)); + MachineInstrBuilder MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, + DL, TII.get(Opc), DestReg2) + .addReg(DestReg1) + .addReg(GlobalBaseReg); + if (!UseGOTOFF) + MIB.addImm(0); + AddOptionalDefs(MIB); + + return DestReg2; +} + namespace llvm { FastISel *ARM::createFastISel(FunctionLoweringInfo &funcInfo, const TargetLibraryInfo *libInfo) { diff --git a/lib/Target/ARM/ARMInstrInfo.cpp b/lib/Target/ARM/ARMInstrInfo.cpp index 31b0c41f08f..e62187727c9 100644 --- a/lib/Target/ARM/ARMInstrInfo.cpp +++ b/lib/Target/ARM/ARMInstrInfo.cpp @@ -13,13 +13,17 @@ #include "ARMInstrInfo.h" #include "ARM.h" +#include "ARMConstantPoolValue.h" #include "ARMMachineFunctionInfo.h" +#include "ARMTargetMachine.h" #include "MCTargetDesc/ARMAddressingModes.h" #include "llvm/ADT/STLExtras.h" #include "llvm/CodeGen/LiveVariables.h" #include "llvm/CodeGen/MachineFrameInfo.h" #include "llvm/CodeGen/MachineInstrBuilder.h" #include "llvm/CodeGen/MachineJumpTableInfo.h" +#include "llvm/Function.h" +#include "llvm/GlobalVariable.h" #include "llvm/MC/MCAsmInfo.h" #include "llvm/MC/MCInst.h" using namespace llvm; @@ -84,3 +88,61 @@ unsigned ARMInstrInfo::getUnindexedOpcode(unsigned Opc) const { return 0; } + +namespace { + /// ARMCGBR - Create Global Base Reg pass. This initializes the PIC + /// global base register for ARM ELF. + struct ARMCGBR : public MachineFunctionPass { + static char ID; + ARMCGBR() : MachineFunctionPass(ID) {} + + virtual bool runOnMachineFunction(MachineFunction &MF) { + ARMFunctionInfo *AFI = MF.getInfo(); + if (AFI->getGlobalBaseReg() == 0) + return false; + + const ARMTargetMachine *TM = + static_cast(&MF.getTarget()); + if (TM->getRelocationModel() != Reloc::PIC_) + return false; + + LLVMContext* Context = &MF.getFunction()->getContext(); + GlobalValue *GV = new GlobalVariable(Type::getInt32Ty(*Context), false, + GlobalValue::ExternalLinkage, 0, + "_GLOBAL_OFFSET_TABLE_"); + unsigned Id = AFI->createPICLabelUId(); + ARMConstantPoolValue *CPV = ARMConstantPoolConstant::Create(GV, Id); + unsigned Align = TM->getTargetData()->getPrefTypeAlignment(GV->getType()); + unsigned Idx = MF.getConstantPool()->getConstantPoolIndex(CPV, Align); + + MachineBasicBlock &FirstMBB = MF.front(); + MachineBasicBlock::iterator MBBI = FirstMBB.begin(); + DebugLoc DL = FirstMBB.findDebugLoc(MBBI); + unsigned GlobalBaseReg = AFI->getGlobalBaseReg(); + unsigned Opc = TM->getSubtarget().isThumb2() ? + ARM::t2LDRpci : ARM::LDRcp; + const TargetInstrInfo &TII = *TM->getInstrInfo(); + MachineInstrBuilder MIB = BuildMI(FirstMBB, MBBI, DL, + TII.get(Opc), GlobalBaseReg) + .addConstantPoolIndex(Idx); + if (Opc == ARM::LDRcp) + MIB.addImm(0); + AddDefaultPred(MIB); + + return true; + } + + virtual const char *getPassName() const { + return "ARM PIC Global Base Reg Initialization"; + } + + virtual void getAnalysisUsage(AnalysisUsage &AU) const { + AU.setPreservesCFG(); + MachineFunctionPass::getAnalysisUsage(AU); + } + }; +} + +char ARMCGBR::ID = 0; +FunctionPass* +llvm::createARMGlobalBaseRegPass() { return new ARMCGBR(); } diff --git a/lib/Target/ARM/ARMMachineFunctionInfo.h b/lib/Target/ARM/ARMMachineFunctionInfo.h index f1c8fc84816..c0ac04b6003 100644 --- a/lib/Target/ARM/ARMMachineFunctionInfo.h +++ b/lib/Target/ARM/ARMMachineFunctionInfo.h @@ -108,6 +108,11 @@ class ARMFunctionInfo : public MachineFunctionInfo { /// pass. DenseMap CPEClones; + /// GlobalBaseReg - keeps track of the virtual register initialized for + /// use as the global base register. This is used for PIC in some PIC + /// relocation models. + unsigned GlobalBaseReg; + public: ARMFunctionInfo() : isThumb(false), @@ -119,7 +124,7 @@ public: GPRCS1Frames(0), GPRCS2Frames(0), DPRCSFrames(0), NumAlignedDPRCS2Regs(0), JumpTableUId(0), PICLabelUId(0), - VarArgsFrameIndex(0), HasITBlocks(false) {} + VarArgsFrameIndex(0), HasITBlocks(false), GlobalBaseReg(0) {} explicit ARMFunctionInfo(MachineFunction &MF) : isThumb(MF.getTarget().getSubtarget().isThumb()), @@ -130,7 +135,7 @@ public: GPRCS1Size(0), GPRCS2Size(0), DPRCSSize(0), GPRCS1Frames(32), GPRCS2Frames(32), DPRCSFrames(32), JumpTableUId(0), PICLabelUId(0), - VarArgsFrameIndex(0), HasITBlocks(false) {} + VarArgsFrameIndex(0), HasITBlocks(false), GlobalBaseReg(0) {} bool isThumbFunction() const { return isThumb; } bool isThumb1OnlyFunction() const { return isThumb && !hasThumb2; } @@ -249,6 +254,9 @@ public: bool hasITBlocks() const { return HasITBlocks; } void setHasITBlocks(bool h) { HasITBlocks = h; } + unsigned getGlobalBaseReg() const { return GlobalBaseReg; } + void setGlobalBaseReg(unsigned Reg) { GlobalBaseReg = Reg; } + void recordCPEClone(unsigned CPIdx, unsigned CPCloneIdx) { if (!CPEClones.insert(std::make_pair(CPCloneIdx, CPIdx)).second) assert(0 && "Duplicate entries!"); diff --git a/lib/Target/ARM/ARMTargetMachine.cpp b/lib/Target/ARM/ARMTargetMachine.cpp index 133a7dd8c76..42fbc5e52a7 100644 --- a/lib/Target/ARM/ARMTargetMachine.cpp +++ b/lib/Target/ARM/ARMTargetMachine.cpp @@ -143,6 +143,11 @@ bool ARMPassConfig::addPreISel() { bool ARMPassConfig::addInstSelector() { addPass(createARMISelDag(getARMTargetMachine(), getOptLevel())); + + const ARMSubtarget *Subtarget = &getARMSubtarget(); + if (Subtarget->isTargetELF() && !Subtarget->isThumb1Only() && + TM->Options.EnableFastISel) + addPass(createARMGlobalBaseRegPass()); return false; } diff --git a/test/CodeGen/ARM/fast-isel-pic.ll b/test/CodeGen/ARM/fast-isel-pic.ll index 392a845d2cc..867d53f973d 100644 --- a/test/CodeGen/ARM/fast-isel-pic.ll +++ b/test/CodeGen/ARM/fast-isel-pic.ll @@ -1,6 +1,8 @@ ; RUN: llc < %s -O0 -fast-isel-abort -relocation-model=pic -mtriple=thumbv7-apple-ios | FileCheck %s --check-prefix=THUMB ; RUN: llc < %s -O0 -fast-isel-abort -relocation-model=pic -mtriple=arm-apple-ios | FileCheck %s --check-prefix=ARM ; RUN: llc < %s -O0 -fast-isel-abort -relocation-model=pic -mtriple=armv7-apple-ios | FileCheck %s --check-prefix=ARMv7 +; RUN: llc < %s -O0 -fast-isel-abort -relocation-model=pic -mtriple=thumbv7-none-linux-gnueabi | FileCheck %s --check-prefix=THUMB-ELF +; RUN: llc < %s -O0 -fast-isel-abort -relocation-model=pic -mtriple=armv7-none-linux-gnueabi | FileCheck %s --check-prefix=ARMv7-ELF @g = global i32 0, align 4 @@ -10,6 +12,10 @@ entry: ; THUMB: movw [[reg0:r[0-9]+]], ; THUMB: movt [[reg0]], ; THUMB: add [[reg0]], pc +; THUMB-ELF: LoadGV +; THUMB-ELF: ldr.n r[[reg0:[0-9]+]], +; THUMB-ELF: ldr.n r[[reg1:[0-9]+]], +; THUMB-ELF: ldr r[[reg0]], [r[[reg1]], r[[reg0]]] ; ARM: LoadGV ; ARM: ldr [[reg1:r[0-9]+]], ; ARM: add [[reg1]], pc, [[reg1]] @@ -17,6 +23,10 @@ entry: ; ARMv7: movw [[reg2:r[0-9]+]], ; ARMv7: movt [[reg2]], ; ARMv7: add [[reg2]], pc, [[reg2]] +; ARMv7-ELF: LoadGV +; ARMv7-ELF: ldr r[[reg2:[0-9]+]], +; ARMv7-ELF: ldr r[[reg3:[0-9]+]], +; ARMv7-ELF: ldr r[[reg2]], [r[[reg3]], r[[reg2]]] %tmp = load i32* @g ret i32 %tmp } @@ -30,6 +40,10 @@ entry: ; THUMB: movt r[[reg3]], ; THUMB: add r[[reg3]], pc ; THUMB: ldr r[[reg3]], [r[[reg3]]] +; THUMB-ELF: LoadIndirectSymbol +; THUMB-ELF: ldr.n r[[reg3:[0-9]+]], +; THUMB-ELF: ldr.n r[[reg4:[0-9]+]], +; THUMB-ELF: ldr r[[reg3]], [r[[reg4]], r[[reg3]]] ; ARM: LoadIndirectSymbol ; ARM: ldr [[reg4:r[0-9]+]], ; ARM: ldr [[reg4]], [pc, [[reg4]]] @@ -38,6 +52,10 @@ entry: ; ARMv7: movt r[[reg5]], ; ARMv7: add r[[reg5]], pc, r[[reg5]] ; ARMv7: ldr r[[reg5]], [r[[reg5]]] +; ARMv7-ELF: LoadIndirectSymbol +; ARMv7-ELF: ldr r[[reg5:[0-9]+]], +; ARMv7-ELF: ldr r[[reg6:[0-9]+]], +; ARMv7-ELF: ldr r[[reg5]], [r[[reg6]], r[[reg5]]] %tmp = load i32* @i ret i32 %tmp } -- 2.34.1