-//===- ARMBaseRegisterInfo.cpp - ARM Register Information -------*- C++ -*-===//
+//===-- ARMBaseRegisterInfo.cpp - ARM Register Information ----------------===//
//
// The LLVM Compiler Infrastructure
//
//
//===----------------------------------------------------------------------===//
+#include "ARMBaseRegisterInfo.h"
#include "ARM.h"
-#include "ARMAddressingModes.h"
#include "ARMBaseInstrInfo.h"
-#include "ARMBaseRegisterInfo.h"
-#include "ARMInstrInfo.h"
+#include "ARMFrameLowering.h"
#include "ARMMachineFunctionInfo.h"
#include "ARMSubtarget.h"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Function.h"
-#include "llvm/LLVMContext.h"
+#include "MCTargetDesc/ARMAddressingModes.h"
+#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/CodeGen/MachineLocation.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterScavenging.h"
+#include "llvm/CodeGen/VirtRegMap.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/LLVMContext.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/Target/TargetFrameInfo.h"
+#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
-#include "llvm/ADT/BitVector.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/Support/CommandLine.h"
-
-namespace llvm {
-static cl::opt<bool>
-ForceAllBaseRegAlloc("arm-force-base-reg-alloc", cl::Hidden, cl::init(false),
- cl::desc("Force use of virtual base registers for stack load/store"));
-static cl::opt<bool>
-EnableLocalStackAlloc("enable-local-stack-alloc", cl::init(true), cl::Hidden,
- cl::desc("Enable pre-regalloc stack frame index allocation"));
-}
-using namespace llvm;
+#define DEBUG_TYPE "arm-register-info"
-static cl::opt<bool>
-EnableBasePointer("arm-use-base-pointer", cl::Hidden, cl::init(true),
- cl::desc("Enable use of a base pointer for complex stack frames"));
+#define GET_REGINFO_TARGET_DESC
+#include "ARMGenRegisterInfo.inc"
+using namespace llvm;
+
+ARMBaseRegisterInfo::ARMBaseRegisterInfo()
+ : ARMGenRegisterInfo(ARM::LR, 0, 0, ARM::PC), BasePtr(ARM::R6) {}
-ARMBaseRegisterInfo::ARMBaseRegisterInfo(const ARMBaseInstrInfo &tii,
- const ARMSubtarget &sti)
- : ARMGenRegisterInfo(ARM::ADJCALLSTACKDOWN, ARM::ADJCALLSTACKUP),
- TII(tii), STI(sti),
- FramePtr((STI.isTargetDarwin() || STI.isThumb()) ? ARM::R7 : ARM::R11),
- BasePtr(ARM::R6) {
+static unsigned getFramePointerReg(const ARMSubtarget &STI) {
+ if (STI.isTargetMachO()) {
+ if (STI.isTargetDarwin() || STI.isThumb1Only())
+ return ARM::R7;
+ else
+ return ARM::R11;
+ } else if (STI.isTargetWindows())
+ return ARM::R11;
+ else // ARM EABI
+ return STI.isThumb() ? ARM::R7 : ARM::R11;
}
-const unsigned*
+const MCPhysReg*
ARMBaseRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
- static const unsigned CalleeSavedRegs[] = {
- ARM::LR, ARM::R11, ARM::R10, ARM::R9, ARM::R8,
- ARM::R7, ARM::R6, ARM::R5, ARM::R4,
-
- ARM::D15, ARM::D14, ARM::D13, ARM::D12,
- ARM::D11, ARM::D10, ARM::D9, ARM::D8,
- 0
- };
-
- static const unsigned DarwinCalleeSavedRegs[] = {
- // Darwin ABI deviates from ARM standard ABI. R9 is not a callee-saved
- // register.
- ARM::LR, ARM::R7, ARM::R6, ARM::R5, ARM::R4,
- ARM::R11, ARM::R10, ARM::R8,
-
- ARM::D15, ARM::D14, ARM::D13, ARM::D12,
- ARM::D11, ARM::D10, ARM::D9, ARM::D8,
- 0
- };
- return STI.isTargetDarwin() ? DarwinCalleeSavedRegs : CalleeSavedRegs;
+ const ARMSubtarget &STI = MF->getSubtarget<ARMSubtarget>();
+ const MCPhysReg *RegList =
+ STI.isTargetDarwin() ? CSR_iOS_SaveList : CSR_AAPCS_SaveList;
+
+ const Function *F = MF->getFunction();
+ if (F->getCallingConv() == CallingConv::GHC) {
+ // GHC set of callee saved regs is empty as all those regs are
+ // used for passing STG regs around
+ return CSR_NoRegs_SaveList;
+ } else if (F->hasFnAttribute("interrupt")) {
+ if (STI.isMClass()) {
+ // M-class CPUs have hardware which saves the registers needed to allow a
+ // function conforming to the AAPCS to function as a handler.
+ return CSR_AAPCS_SaveList;
+ } else if (F->getFnAttribute("interrupt").getValueAsString() == "FIQ") {
+ // Fast interrupt mode gives the handler a private copy of R8-R14, so less
+ // need to be saved to restore user-mode state.
+ return CSR_FIQ_SaveList;
+ } else {
+ // Generally only R13-R14 (i.e. SP, LR) are automatically preserved by
+ // exception handling.
+ return CSR_GenericInt_SaveList;
+ }
+ }
+
+ return RegList;
+}
+
+const uint32_t *
+ARMBaseRegisterInfo::getCallPreservedMask(const MachineFunction &MF,
+ CallingConv::ID CC) const {
+ const ARMSubtarget &STI = MF.getSubtarget<ARMSubtarget>();
+ if (CC == CallingConv::GHC)
+ // This is academic becase all GHC calls are (supposed to be) tail calls
+ return CSR_NoRegs_RegMask;
+ return STI.isTargetDarwin() ? CSR_iOS_RegMask : CSR_AAPCS_RegMask;
+}
+
+const uint32_t*
+ARMBaseRegisterInfo::getNoPreservedMask() const {
+ return CSR_NoRegs_RegMask;
+}
+
+const uint32_t *
+ARMBaseRegisterInfo::getThisReturnPreservedMask(const MachineFunction &MF,
+ CallingConv::ID CC) const {
+ const ARMSubtarget &STI = MF.getSubtarget<ARMSubtarget>();
+ // This should return a register mask that is the same as that returned by
+ // getCallPreservedMask but that additionally preserves the register used for
+ // the first i32 argument (which must also be the register used to return a
+ // single i32 return value)
+ //
+ // In case that the calling convention does not use the same register for
+ // both or otherwise does not want to enable this optimization, the function
+ // should return NULL
+ if (CC == CallingConv::GHC)
+ // This is academic becase all GHC calls are (supposed to be) tail calls
+ return nullptr;
+ return STI.isTargetDarwin() ? CSR_iOS_ThisReturn_RegMask
+ : CSR_AAPCS_ThisReturn_RegMask;
}
BitVector ARMBaseRegisterInfo::
getReservedRegs(const MachineFunction &MF) const {
- // FIXME: avoid re-calculating this everytime.
+ const ARMSubtarget &STI = MF.getSubtarget<ARMSubtarget>();
+ const ARMFrameLowering *TFI = getFrameLowering(MF);
+
+ // FIXME: avoid re-calculating this every time.
BitVector Reserved(getNumRegs());
Reserved.set(ARM::SP);
Reserved.set(ARM::PC);
Reserved.set(ARM::FPSCR);
- if (hasFP(MF))
- Reserved.set(FramePtr);
+ Reserved.set(ARM::APSR_NZCV);
+ if (TFI->hasFP(MF))
+ Reserved.set(getFramePointerReg(STI));
if (hasBasePointer(MF))
Reserved.set(BasePtr);
// Some targets reserve R9.
if (STI.isR9Reserved())
Reserved.set(ARM::R9);
- return Reserved;
-}
-
-bool ARMBaseRegisterInfo::isReservedReg(const MachineFunction &MF,
- unsigned Reg) const {
- switch (Reg) {
- default: break;
- case ARM::SP:
- case ARM::PC:
- return true;
- case ARM::R6:
- if (hasBasePointer(MF))
- return true;
- break;
- case ARM::R7:
- case ARM::R11:
- if (FramePtr == Reg && hasFP(MF))
- return true;
- break;
- case ARM::R9:
- return STI.isR9Reserved();
+ // Reserve D16-D31 if the subtarget doesn't support them.
+ if (!STI.hasVFP3() || STI.hasD16()) {
+ assert(ARM::D31 == ARM::D16 + 15);
+ for (unsigned i = 0; i != 16; ++i)
+ Reserved.set(ARM::D16 + i);
}
+ const TargetRegisterClass *RC = &ARM::GPRPairRegClass;
+ for(TargetRegisterClass::iterator I = RC->begin(), E = RC->end(); I!=E; ++I)
+ for (MCSubRegIterator SI(*I, this); SI.isValid(); ++SI)
+ if (Reserved.test(*SI)) Reserved.set(*I);
- return false;
+ return Reserved;
}
const TargetRegisterClass *
-ARMBaseRegisterInfo::getMatchingSuperRegClass(const TargetRegisterClass *A,
- const TargetRegisterClass *B,
- unsigned SubIdx) const {
- switch (SubIdx) {
- default: return 0;
- case ARM::ssub_0:
- case ARM::ssub_1:
- case ARM::ssub_2:
- case ARM::ssub_3: {
- // S sub-registers.
- if (A->getSize() == 8) {
- if (B == &ARM::SPR_8RegClass)
- return &ARM::DPR_8RegClass;
- assert(B == &ARM::SPRRegClass && "Expecting SPR register class!");
- if (A == &ARM::DPR_8RegClass)
- return A;
- return &ARM::DPR_VFP2RegClass;
- }
-
- if (A->getSize() == 16) {
- if (B == &ARM::SPR_8RegClass)
- return &ARM::QPR_8RegClass;
- return &ARM::QPR_VFP2RegClass;
+ARMBaseRegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC,
+ const MachineFunction &) const {
+ const TargetRegisterClass *Super = RC;
+ TargetRegisterClass::sc_iterator I = RC->getSuperClasses();
+ do {
+ switch (Super->getID()) {
+ case ARM::GPRRegClassID:
+ case ARM::SPRRegClassID:
+ case ARM::DPRRegClassID:
+ case ARM::QPRRegClassID:
+ case ARM::QQPRRegClassID:
+ case ARM::QQQQPRRegClassID:
+ case ARM::GPRPairRegClassID:
+ return Super;
}
+ Super = *I++;
+ } while (Super);
+ return RC;
+}
- if (A->getSize() == 32) {
- if (B == &ARM::SPR_8RegClass)
- return 0; // Do not allow coalescing!
- return &ARM::QQPR_VFP2RegClass;
- }
+const TargetRegisterClass *
+ARMBaseRegisterInfo::getPointerRegClass(const MachineFunction &MF, unsigned Kind)
+ const {
+ return &ARM::GPRRegClass;
+}
- assert(A->getSize() == 64 && "Expecting a QQQQ register class!");
- return 0; // Do not allow coalescing!
- }
- case ARM::dsub_0:
- case ARM::dsub_1:
- case ARM::dsub_2:
- case ARM::dsub_3: {
- // D sub-registers.
- if (A->getSize() == 16) {
- if (B == &ARM::DPR_VFP2RegClass)
- return &ARM::QPR_VFP2RegClass;
- if (B == &ARM::DPR_8RegClass)
- return 0; // Do not allow coalescing!
- return A;
- }
+const TargetRegisterClass *
+ARMBaseRegisterInfo::getCrossCopyRegClass(const TargetRegisterClass *RC) const {
+ if (RC == &ARM::CCRRegClass)
+ return &ARM::rGPRRegClass; // Can't copy CCR registers.
+ return RC;
+}
- if (A->getSize() == 32) {
- if (B == &ARM::DPR_VFP2RegClass)
- return &ARM::QQPR_VFP2RegClass;
- if (B == &ARM::DPR_8RegClass)
- return 0; // Do not allow coalescing!
- return A;
- }
+unsigned
+ARMBaseRegisterInfo::getRegPressureLimit(const TargetRegisterClass *RC,
+ MachineFunction &MF) const {
+ const ARMSubtarget &STI = MF.getSubtarget<ARMSubtarget>();
+ const ARMFrameLowering *TFI = getFrameLowering(MF);
- assert(A->getSize() == 64 && "Expecting a QQQQ register class!");
- if (B != &ARM::DPRRegClass)
- return 0; // Do not allow coalescing!
- return A;
+ switch (RC->getID()) {
+ default:
+ return 0;
+ case ARM::tGPRRegClassID:
+ return TFI->hasFP(MF) ? 4 : 5;
+ case ARM::GPRRegClassID: {
+ unsigned FP = TFI->hasFP(MF) ? 1 : 0;
+ return 10 - FP - (STI.isR9Reserved() ? 1 : 0);
}
- case ARM::dsub_4:
- case ARM::dsub_5:
- case ARM::dsub_6:
- case ARM::dsub_7: {
- // D sub-registers of QQQQ registers.
- if (A->getSize() == 64 && B == &ARM::DPRRegClass)
- return A;
- return 0; // Do not allow coalescing!
+ case ARM::SPRRegClassID: // Currently not used as 'rep' register class.
+ case ARM::DPRRegClassID:
+ return 32 - 10;
}
+}
- case ARM::qsub_0:
- case ARM::qsub_1: {
- // Q sub-registers.
- if (A->getSize() == 32) {
- if (B == &ARM::QPR_VFP2RegClass)
- return &ARM::QQPR_VFP2RegClass;
- if (B == &ARM::QPR_8RegClass)
- return 0; // Do not allow coalescing!
- return A;
- }
-
- assert(A->getSize() == 64 && "Expecting a QQQQ register class!");
- if (B == &ARM::QPRRegClass)
- return A;
- return 0; // Do not allow coalescing!
- }
- case ARM::qsub_2:
- case ARM::qsub_3: {
- // Q sub-registers of QQQQ registers.
- if (A->getSize() == 64 && B == &ARM::QPRRegClass)
- return A;
- return 0; // Do not allow coalescing!
- }
- }
+// Get the other register in a GPRPair.
+static unsigned getPairedGPR(unsigned Reg, bool Odd, const MCRegisterInfo *RI) {
+ for (MCSuperRegIterator Supers(Reg, RI); Supers.isValid(); ++Supers)
+ if (ARM::GPRPairRegClass.contains(*Supers))
+ return RI->getSubReg(*Supers, Odd ? ARM::gsub_1 : ARM::gsub_0);
return 0;
}
-bool
-ARMBaseRegisterInfo::canCombineSubRegIndices(const TargetRegisterClass *RC,
- SmallVectorImpl<unsigned> &SubIndices,
- unsigned &NewSubIdx) const {
+// Resolve the RegPairEven / RegPairOdd register allocator hints.
+void
+ARMBaseRegisterInfo::getRegAllocationHints(unsigned VirtReg,
+ ArrayRef<MCPhysReg> Order,
+ SmallVectorImpl<MCPhysReg> &Hints,
+ const MachineFunction &MF,
+ const VirtRegMap *VRM,
+ const LiveRegMatrix *Matrix) const {
+ const MachineRegisterInfo &MRI = MF.getRegInfo();
+ std::pair<unsigned, unsigned> Hint = MRI.getRegAllocationHint(VirtReg);
+
+ unsigned Odd;
+ switch (Hint.first) {
+ case ARMRI::RegPairEven:
+ Odd = 0;
+ break;
+ case ARMRI::RegPairOdd:
+ Odd = 1;
+ break;
+ default:
+ TargetRegisterInfo::getRegAllocationHints(VirtReg, Order, Hints, MF, VRM);
+ return;
+ }
- unsigned Size = RC->getSize() * 8;
- if (Size < 6)
- return 0;
+ // This register should preferably be even (Odd == 0) or odd (Odd == 1).
+ // Check if the other part of the pair has already been assigned, and provide
+ // the paired register as the first hint.
+ unsigned Paired = Hint.second;
+ if (Paired == 0)
+ return;
- NewSubIdx = 0; // Whole register.
- unsigned NumRegs = SubIndices.size();
- if (NumRegs == 8) {
- // 8 D registers -> 1 QQQQ register.
- return (Size == 512 &&
- SubIndices[0] == ARM::dsub_0 &&
- SubIndices[1] == ARM::dsub_1 &&
- SubIndices[2] == ARM::dsub_2 &&
- SubIndices[3] == ARM::dsub_3 &&
- SubIndices[4] == ARM::dsub_4 &&
- SubIndices[5] == ARM::dsub_5 &&
- SubIndices[6] == ARM::dsub_6 &&
- SubIndices[7] == ARM::dsub_7);
- } else if (NumRegs == 4) {
- if (SubIndices[0] == ARM::qsub_0) {
- // 4 Q registers -> 1 QQQQ register.
- return (Size == 512 &&
- SubIndices[1] == ARM::qsub_1 &&
- SubIndices[2] == ARM::qsub_2 &&
- SubIndices[3] == ARM::qsub_3);
- } else if (SubIndices[0] == ARM::dsub_0) {
- // 4 D registers -> 1 QQ register.
- if (Size >= 256 &&
- SubIndices[1] == ARM::dsub_1 &&
- SubIndices[2] == ARM::dsub_2 &&
- SubIndices[3] == ARM::dsub_3) {
- if (Size == 512)
- NewSubIdx = ARM::qqsub_0;
- return true;
- }
- } else if (SubIndices[0] == ARM::dsub_4) {
- // 4 D registers -> 1 QQ register (2nd).
- if (Size == 512 &&
- SubIndices[1] == ARM::dsub_5 &&
- SubIndices[2] == ARM::dsub_6 &&
- SubIndices[3] == ARM::dsub_7) {
- NewSubIdx = ARM::qqsub_1;
- return true;
- }
- } else if (SubIndices[0] == ARM::ssub_0) {
- // 4 S registers -> 1 Q register.
- if (Size >= 128 &&
- SubIndices[1] == ARM::ssub_1 &&
- SubIndices[2] == ARM::ssub_2 &&
- SubIndices[3] == ARM::ssub_3) {
- if (Size >= 256)
- NewSubIdx = ARM::qsub_0;
- return true;
- }
- }
- } else if (NumRegs == 2) {
- if (SubIndices[0] == ARM::qsub_0) {
- // 2 Q registers -> 1 QQ register.
- if (Size >= 256 && SubIndices[1] == ARM::qsub_1) {
- if (Size == 512)
- NewSubIdx = ARM::qqsub_0;
- return true;
- }
- } else if (SubIndices[0] == ARM::qsub_2) {
- // 2 Q registers -> 1 QQ register (2nd).
- if (Size == 512 && SubIndices[1] == ARM::qsub_3) {
- NewSubIdx = ARM::qqsub_1;
- return true;
- }
- } else if (SubIndices[0] == ARM::dsub_0) {
- // 2 D registers -> 1 Q register.
- if (Size >= 128 && SubIndices[1] == ARM::dsub_1) {
- if (Size >= 256)
- NewSubIdx = ARM::qsub_0;
- return true;
- }
- } else if (SubIndices[0] == ARM::dsub_2) {
- // 2 D registers -> 1 Q register (2nd).
- if (Size >= 256 && SubIndices[1] == ARM::dsub_3) {
- NewSubIdx = ARM::qsub_1;
- return true;
- }
- } else if (SubIndices[0] == ARM::dsub_4) {
- // 2 D registers -> 1 Q register (3rd).
- if (Size == 512 && SubIndices[1] == ARM::dsub_5) {
- NewSubIdx = ARM::qsub_2;
- return true;
- }
- } else if (SubIndices[0] == ARM::dsub_6) {
- // 2 D registers -> 1 Q register (3rd).
- if (Size == 512 && SubIndices[1] == ARM::dsub_7) {
- NewSubIdx = ARM::qsub_3;
- return true;
- }
- } else if (SubIndices[0] == ARM::ssub_0) {
- // 2 S registers -> 1 D register.
- if (SubIndices[1] == ARM::ssub_1) {
- if (Size >= 128)
- NewSubIdx = ARM::dsub_0;
- return true;
- }
- } else if (SubIndices[0] == ARM::ssub_2) {
- // 2 S registers -> 1 D register (2nd).
- if (Size >= 128 && SubIndices[1] == ARM::ssub_3) {
- NewSubIdx = ARM::dsub_1;
- return true;
- }
- }
+ unsigned PairedPhys = 0;
+ if (TargetRegisterInfo::isPhysicalRegister(Paired)) {
+ PairedPhys = Paired;
+ } else if (VRM && VRM->hasPhys(Paired)) {
+ PairedPhys = getPairedGPR(VRM->getPhys(Paired), Odd, this);
}
- return false;
-}
-
-const TargetRegisterClass *
-ARMBaseRegisterInfo::getPointerRegClass(unsigned Kind) const {
- return ARM::GPRRegisterClass;
-}
+ // First prefer the paired physreg.
+ if (PairedPhys &&
+ std::find(Order.begin(), Order.end(), PairedPhys) != Order.end())
+ Hints.push_back(PairedPhys);
-/// getAllocationOrder - Returns the register allocation order for a specified
-/// register class in the form of a pair of TargetRegisterClass iterators.
-std::pair<TargetRegisterClass::iterator,TargetRegisterClass::iterator>
-ARMBaseRegisterInfo::getAllocationOrder(const TargetRegisterClass *RC,
- unsigned HintType, unsigned HintReg,
- const MachineFunction &MF) const {
- // Alternative register allocation orders when favoring even / odd registers
- // of register pairs.
-
- // No FP, R9 is available.
- static const unsigned GPREven1[] = {
- ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R8, ARM::R10,
- ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R7,
- ARM::R9, ARM::R11
- };
- static const unsigned GPROdd1[] = {
- ARM::R1, ARM::R3, ARM::R5, ARM::R7, ARM::R9, ARM::R11,
- ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6,
- ARM::R8, ARM::R10
- };
-
- // FP is R7, R9 is available.
- static const unsigned GPREven2[] = {
- ARM::R0, ARM::R2, ARM::R4, ARM::R8, ARM::R10,
- ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R6,
- ARM::R9, ARM::R11
- };
- static const unsigned GPROdd2[] = {
- ARM::R1, ARM::R3, ARM::R5, ARM::R9, ARM::R11,
- ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6,
- ARM::R8, ARM::R10
- };
-
- // FP is R11, R9 is available.
- static const unsigned GPREven3[] = {
- ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R8,
- ARM::R1, ARM::R3, ARM::R10,ARM::R12,ARM::LR, ARM::R5, ARM::R7,
- ARM::R9
- };
- static const unsigned GPROdd3[] = {
- ARM::R1, ARM::R3, ARM::R5, ARM::R6, ARM::R9,
- ARM::R0, ARM::R2, ARM::R10,ARM::R12,ARM::LR, ARM::R4, ARM::R7,
- ARM::R8
- };
-
- // No FP, R9 is not available.
- static const unsigned GPREven4[] = {
- ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R10,
- ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R7, ARM::R8,
- ARM::R11
- };
- static const unsigned GPROdd4[] = {
- ARM::R1, ARM::R3, ARM::R5, ARM::R7, ARM::R11,
- ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8,
- ARM::R10
- };
-
- // FP is R7, R9 is not available.
- static const unsigned GPREven5[] = {
- ARM::R0, ARM::R2, ARM::R4, ARM::R10,
- ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R6, ARM::R8,
- ARM::R11
- };
- static const unsigned GPROdd5[] = {
- ARM::R1, ARM::R3, ARM::R5, ARM::R11,
- ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8,
- ARM::R10
- };
-
- // FP is R11, R9 is not available.
- static const unsigned GPREven6[] = {
- ARM::R0, ARM::R2, ARM::R4, ARM::R6,
- ARM::R1, ARM::R3, ARM::R10,ARM::R12,ARM::LR, ARM::R5, ARM::R7, ARM::R8
- };
- static const unsigned GPROdd6[] = {
- ARM::R1, ARM::R3, ARM::R5, ARM::R7,
- ARM::R0, ARM::R2, ARM::R10,ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8
- };
-
-
- if (HintType == ARMRI::RegPairEven) {
- if (isPhysicalRegister(HintReg) && getRegisterPairEven(HintReg, MF) == 0)
- // It's no longer possible to fulfill this hint. Return the default
- // allocation order.
- return std::make_pair(RC->allocation_order_begin(MF),
- RC->allocation_order_end(MF));
-
- if (!hasFP(MF)) {
- if (!STI.isR9Reserved())
- return std::make_pair(GPREven1,
- GPREven1 + (sizeof(GPREven1)/sizeof(unsigned)));
- else
- return std::make_pair(GPREven4,
- GPREven4 + (sizeof(GPREven4)/sizeof(unsigned)));
- } else if (FramePtr == ARM::R7) {
- if (!STI.isR9Reserved())
- return std::make_pair(GPREven2,
- GPREven2 + (sizeof(GPREven2)/sizeof(unsigned)));
- else
- return std::make_pair(GPREven5,
- GPREven5 + (sizeof(GPREven5)/sizeof(unsigned)));
- } else { // FramePtr == ARM::R11
- if (!STI.isR9Reserved())
- return std::make_pair(GPREven3,
- GPREven3 + (sizeof(GPREven3)/sizeof(unsigned)));
- else
- return std::make_pair(GPREven6,
- GPREven6 + (sizeof(GPREven6)/sizeof(unsigned)));
- }
- } else if (HintType == ARMRI::RegPairOdd) {
- if (isPhysicalRegister(HintReg) && getRegisterPairOdd(HintReg, MF) == 0)
- // It's no longer possible to fulfill this hint. Return the default
- // allocation order.
- return std::make_pair(RC->allocation_order_begin(MF),
- RC->allocation_order_end(MF));
-
- if (!hasFP(MF)) {
- if (!STI.isR9Reserved())
- return std::make_pair(GPROdd1,
- GPROdd1 + (sizeof(GPROdd1)/sizeof(unsigned)));
- else
- return std::make_pair(GPROdd4,
- GPROdd4 + (sizeof(GPROdd4)/sizeof(unsigned)));
- } else if (FramePtr == ARM::R7) {
- if (!STI.isR9Reserved())
- return std::make_pair(GPROdd2,
- GPROdd2 + (sizeof(GPROdd2)/sizeof(unsigned)));
- else
- return std::make_pair(GPROdd5,
- GPROdd5 + (sizeof(GPROdd5)/sizeof(unsigned)));
- } else { // FramePtr == ARM::R11
- if (!STI.isR9Reserved())
- return std::make_pair(GPROdd3,
- GPROdd3 + (sizeof(GPROdd3)/sizeof(unsigned)));
- else
- return std::make_pair(GPROdd6,
- GPROdd6 + (sizeof(GPROdd6)/sizeof(unsigned)));
- }
+ // Then prefer even or odd registers.
+ for (unsigned I = 0, E = Order.size(); I != E; ++I) {
+ unsigned Reg = Order[I];
+ if (Reg == PairedPhys || (getEncodingValue(Reg) & 1) != Odd)
+ continue;
+ // Don't provide hints that are paired to a reserved register.
+ unsigned Paired = getPairedGPR(Reg, !Odd, this);
+ if (!Paired || MRI.isReserved(Paired))
+ continue;
+ Hints.push_back(Reg);
}
- return std::make_pair(RC->allocation_order_begin(MF),
- RC->allocation_order_end(MF));
-}
-
-/// ResolveRegAllocHint - Resolves the specified register allocation hint
-/// to a physical register. Returns the physical register if it is successful.
-unsigned
-ARMBaseRegisterInfo::ResolveRegAllocHint(unsigned Type, unsigned Reg,
- const MachineFunction &MF) const {
- if (Reg == 0 || !isPhysicalRegister(Reg))
- return 0;
- if (Type == 0)
- return Reg;
- else if (Type == (unsigned)ARMRI::RegPairOdd)
- // Odd register.
- return getRegisterPairOdd(Reg, MF);
- else if (Type == (unsigned)ARMRI::RegPairEven)
- // Even register.
- return getRegisterPairEven(Reg, MF);
- return 0;
}
void
-ARMBaseRegisterInfo::UpdateRegAllocHint(unsigned Reg, unsigned NewReg,
+ARMBaseRegisterInfo::updateRegAllocHint(unsigned Reg, unsigned NewReg,
MachineFunction &MF) const {
MachineRegisterInfo *MRI = &MF.getRegInfo();
std::pair<unsigned, unsigned> Hint = MRI->getRegAllocationHint(Reg);
if ((Hint.first == (unsigned)ARMRI::RegPairOdd ||
Hint.first == (unsigned)ARMRI::RegPairEven) &&
- Hint.second && TargetRegisterInfo::isVirtualRegister(Hint.second)) {
+ TargetRegisterInfo::isVirtualRegister(Hint.second)) {
// If 'Reg' is one of the even / odd register pair and it's now changed
// (e.g. coalesced) into a different register. The other register of the
// pair allocation hint must be updated to reflect the relationship
// change.
unsigned OtherReg = Hint.second;
Hint = MRI->getRegAllocationHint(OtherReg);
- if (Hint.second == Reg)
- // Make sure the pair has not already divorced.
+ // Make sure the pair has not already divorced.
+ if (Hint.second == Reg) {
MRI->setRegAllocationHint(OtherReg, Hint.first, NewReg);
+ if (TargetRegisterInfo::isVirtualRegister(NewReg))
+ MRI->setRegAllocationHint(NewReg,
+ Hint.first == (unsigned)ARMRI::RegPairOdd ? ARMRI::RegPairEven
+ : ARMRI::RegPairOdd, OtherReg);
+ }
}
}
-/// hasFP - Return true if the specified function should have a dedicated frame
-/// pointer register. This is true if the function has variable sized allocas
-/// or if frame pointer elimination is disabled.
-///
-bool ARMBaseRegisterInfo::hasFP(const MachineFunction &MF) const {
- // Mac OS X requires FP not to be clobbered for backtracing purpose.
- if (STI.isTargetDarwin())
- return true;
-
- const MachineFrameInfo *MFI = MF.getFrameInfo();
- // Always eliminate non-leaf frame pointers.
- return ((DisableFramePointerElim(MF) && MFI->hasCalls()) ||
- needsStackRealignment(MF) ||
- MFI->hasVarSizedObjects() ||
- MFI->isFrameAddressTaken());
-}
-
bool ARMBaseRegisterInfo::hasBasePointer(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
+ const ARMFrameLowering *TFI = getFrameLowering(MF);
- if (!EnableBasePointer)
- return false;
-
- if (needsStackRealignment(MF) && MFI->hasVarSizedObjects())
+ // When outgoing call frames are so large that we adjust the stack pointer
+ // around the call, we can no longer use the stack pointer to reach the
+ // emergency spill slot.
+ if (needsStackRealignment(MF) && !TFI->hasReservedCallFrame(MF))
return true;
// Thumb has trouble with negative offsets from the FP. Thumb2 has a limited
}
bool ARMBaseRegisterInfo::canRealignStack(const MachineFunction &MF) const {
- const MachineFrameInfo *MFI = MF.getFrameInfo();
+ const MachineRegisterInfo *MRI = &MF.getRegInfo();
const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
+ const ARMFrameLowering *TFI = getFrameLowering(MF);
// We can't realign the stack if:
// 1. Dynamic stack realignment is explicitly disabled,
// 2. This is a Thumb1 function (it's not useful, so we don't bother), or
// 3. There are VLAs in the function and the base pointer is disabled.
- return (RealignStack && !AFI->isThumb1OnlyFunction() &&
- (!MFI->hasVarSizedObjects() || EnableBasePointer));
-}
-
-bool ARMBaseRegisterInfo::
-needsStackRealignment(const MachineFunction &MF) const {
- const MachineFrameInfo *MFI = MF.getFrameInfo();
- const Function *F = MF.getFunction();
- unsigned StackAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
- bool requiresRealignment = ((MFI->getLocalFrameMaxAlign() > StackAlign) ||
- F->hasFnAttr(Attribute::StackAlignment));
-
- return requiresRealignment && canRealignStack(MF);
+ if (!TargetRegisterInfo::canRealignStack(MF))
+ return false;
+ if (AFI->isThumb1OnlyFunction())
+ return false;
+ // Stack realignment requires a frame pointer. If we already started
+ // register allocation with frame pointer elimination, it is too late now.
+ if (!MRI->canReserveReg(getFramePointerReg(MF.getSubtarget<ARMSubtarget>())))
+ return false;
+ // We may also need a base pointer if there are dynamic allocas or stack
+ // pointer adjustments around calls.
+ if (TFI->hasReservedCallFrame(MF))
+ return true;
+ // A base pointer is required and allowed. Check that it isn't too late to
+ // reserve it.
+ return MRI->canReserveReg(BasePtr);
}
bool ARMBaseRegisterInfo::
cannotEliminateFrame(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
- if (DisableFramePointerElim(MF) && MFI->adjustsStack())
+ if (MF.getTarget().Options.DisableFramePointerElim(MF) && MFI->adjustsStack())
return true;
return MFI->hasVarSizedObjects() || MFI->isFrameAddressTaken()
|| needsStackRealignment(MF);
}
-/// estimateStackSize - Estimate and return the size of the frame.
-static unsigned estimateStackSize(MachineFunction &MF) {
- const MachineFrameInfo *FFI = MF.getFrameInfo();
- int Offset = 0;
- for (int i = FFI->getObjectIndexBegin(); i != 0; ++i) {
- int FixedOff = -FFI->getObjectOffset(i);
- if (FixedOff > Offset) Offset = FixedOff;
- }
- for (unsigned i = 0, e = FFI->getObjectIndexEnd(); i != e; ++i) {
- if (FFI->isDeadObjectIndex(i))
- continue;
- Offset += FFI->getObjectSize(i);
- unsigned Align = FFI->getObjectAlignment(i);
- // Adjust to alignment boundary
- Offset = (Offset+Align-1)/Align*Align;
- }
- return (unsigned)Offset;
-}
-
-/// estimateRSStackSizeLimit - Look at each instruction that references stack
-/// frames and return the stack size limit beyond which some of these
-/// instructions will require a scratch register during their expansion later.
-unsigned
-ARMBaseRegisterInfo::estimateRSStackSizeLimit(MachineFunction &MF) const {
- const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- unsigned Limit = (1 << 12) - 1;
- for (MachineFunction::iterator BB = MF.begin(),E = MF.end(); BB != E; ++BB) {
- for (MachineBasicBlock::iterator I = BB->begin(), E = BB->end();
- I != E; ++I) {
- for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
- if (!I->getOperand(i).isFI()) continue;
-
- // When using ADDri to get the address of a stack object, 255 is the
- // largest offset guaranteed to fit in the immediate offset.
- if (I->getOpcode() == ARM::ADDri) {
- Limit = std::min(Limit, (1U << 8) - 1);
- break;
- }
-
- // Otherwise check the addressing mode.
- switch (I->getDesc().TSFlags & ARMII::AddrModeMask) {
- case ARMII::AddrMode3:
- case ARMII::AddrModeT2_i8:
- Limit = std::min(Limit, (1U << 8) - 1);
- break;
- case ARMII::AddrMode5:
- case ARMII::AddrModeT2_i8s4:
- Limit = std::min(Limit, ((1U << 8) - 1) * 4);
- break;
- case ARMII::AddrModeT2_i12:
- // i12 supports only positive offset so these will be converted to
- // i8 opcodes. See llvm::rewriteT2FrameIndex.
- if (hasFP(MF) && AFI->hasStackFrame())
- Limit = std::min(Limit, (1U << 8) - 1);
- break;
- case ARMII::AddrMode4:
- case ARMII::AddrMode6:
- // Addressing modes 4 & 6 (load/store) instructions can't encode an
- // immediate offset for stack references.
- return 0;
- default:
- break;
- }
- break; // At most one FI per instruction
- }
- }
- }
-
- return Limit;
-}
-
-static unsigned GetFunctionSizeInBytes(const MachineFunction &MF,
- const ARMBaseInstrInfo &TII) {
- unsigned FnSize = 0;
- for (MachineFunction::const_iterator MBBI = MF.begin(), E = MF.end();
- MBBI != E; ++MBBI) {
- const MachineBasicBlock &MBB = *MBBI;
- for (MachineBasicBlock::const_iterator I = MBB.begin(),E = MBB.end();
- I != E; ++I)
- FnSize += TII.GetInstSizeInBytes(I);
- }
- return FnSize;
-}
-
-void
-ARMBaseRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
- RegScavenger *RS) const {
- // This tells PEI to spill the FP as if it is any other callee-save register
- // to take advantage the eliminateFrameIndex machinery. This also ensures it
- // is spilled in the order specified by getCalleeSavedRegs() to make it easier
- // to combine multiple loads / stores.
- bool CanEliminateFrame = true;
- bool CS1Spilled = false;
- bool LRSpilled = false;
- unsigned NumGPRSpills = 0;
- SmallVector<unsigned, 4> UnspilledCS1GPRs;
- SmallVector<unsigned, 4> UnspilledCS2GPRs;
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- MachineFrameInfo *MFI = MF.getFrameInfo();
-
- // Spill R4 if Thumb2 function requires stack realignment - it will be used as
- // scratch register.
- // FIXME: It will be better just to find spare register here.
- if (needsStackRealignment(MF) &&
- AFI->isThumb2Function())
- MF.getRegInfo().setPhysRegUsed(ARM::R4);
-
- // Spill LR if Thumb1 function uses variable length argument lists.
- if (AFI->isThumb1OnlyFunction() && AFI->getVarArgsRegSaveSize() > 0)
- MF.getRegInfo().setPhysRegUsed(ARM::LR);
-
- // Spill the BasePtr if it's used.
- if (hasBasePointer(MF))
- MF.getRegInfo().setPhysRegUsed(BasePtr);
-
- // Don't spill FP if the frame can be eliminated. This is determined
- // by scanning the callee-save registers to see if any is used.
- const unsigned *CSRegs = getCalleeSavedRegs();
- for (unsigned i = 0; CSRegs[i]; ++i) {
- unsigned Reg = CSRegs[i];
- bool Spilled = false;
- if (MF.getRegInfo().isPhysRegUsed(Reg)) {
- AFI->setCSRegisterIsSpilled(Reg);
- Spilled = true;
- CanEliminateFrame = false;
- } else {
- // Check alias registers too.
- for (const unsigned *Aliases = getAliasSet(Reg); *Aliases; ++Aliases) {
- if (MF.getRegInfo().isPhysRegUsed(*Aliases)) {
- Spilled = true;
- CanEliminateFrame = false;
- }
- }
- }
-
- if (!ARM::GPRRegisterClass->contains(Reg))
- continue;
-
- if (Spilled) {
- NumGPRSpills++;
-
- if (!STI.isTargetDarwin()) {
- if (Reg == ARM::LR)
- LRSpilled = true;
- CS1Spilled = true;
- continue;
- }
-
- // Keep track if LR and any of R4, R5, R6, and R7 is spilled.
- switch (Reg) {
- case ARM::LR:
- LRSpilled = true;
- // Fallthrough
- case ARM::R4:
- case ARM::R5:
- case ARM::R6:
- case ARM::R7:
- CS1Spilled = true;
- break;
- default:
- break;
- }
- } else {
- if (!STI.isTargetDarwin()) {
- UnspilledCS1GPRs.push_back(Reg);
- continue;
- }
-
- switch (Reg) {
- case ARM::R4:
- case ARM::R5:
- case ARM::R6:
- case ARM::R7:
- case ARM::LR:
- UnspilledCS1GPRs.push_back(Reg);
- break;
- default:
- UnspilledCS2GPRs.push_back(Reg);
- break;
- }
- }
- }
-
- bool ForceLRSpill = false;
- if (!LRSpilled && AFI->isThumb1OnlyFunction()) {
- unsigned FnSize = GetFunctionSizeInBytes(MF, TII);
- // Force LR to be spilled if the Thumb function size is > 2048. This enables
- // use of BL to implement far jump. If it turns out that it's not needed
- // then the branch fix up path will undo it.
- if (FnSize >= (1 << 11)) {
- CanEliminateFrame = false;
- ForceLRSpill = true;
- }
- }
-
- // If any of the stack slot references may be out of range of an immediate
- // offset, make sure a register (or a spill slot) is available for the
- // register scavenger. Note that if we're indexing off the frame pointer, the
- // effective stack size is 4 bytes larger since the FP points to the stack
- // slot of the previous FP. Also, if we have variable sized objects in the
- // function, stack slot references will often be negative, and some of
- // our instructions are positive-offset only, so conservatively consider
- // that case to want a spill slot (or register) as well. Similarly, if
- // the function adjusts the stack pointer during execution and the
- // adjustments aren't already part of our stack size estimate, our offset
- // calculations may be off, so be conservative.
- // FIXME: We could add logic to be more precise about negative offsets
- // and which instructions will need a scratch register for them. Is it
- // worth the effort and added fragility?
- bool BigStack =
- (RS &&
- (estimateStackSize(MF) + ((hasFP(MF) && AFI->hasStackFrame()) ? 4:0) >=
- estimateRSStackSizeLimit(MF)))
- || MFI->hasVarSizedObjects()
- || (MFI->adjustsStack() && !canSimplifyCallFramePseudos(MF));
-
- bool ExtraCSSpill = false;
- if (BigStack || !CanEliminateFrame || cannotEliminateFrame(MF)) {
- AFI->setHasStackFrame(true);
-
- // If LR is not spilled, but at least one of R4, R5, R6, and R7 is spilled.
- // Spill LR as well so we can fold BX_RET to the registers restore (LDM).
- if (!LRSpilled && CS1Spilled) {
- MF.getRegInfo().setPhysRegUsed(ARM::LR);
- AFI->setCSRegisterIsSpilled(ARM::LR);
- NumGPRSpills++;
- UnspilledCS1GPRs.erase(std::find(UnspilledCS1GPRs.begin(),
- UnspilledCS1GPRs.end(), (unsigned)ARM::LR));
- ForceLRSpill = false;
- ExtraCSSpill = true;
- }
-
- if (hasFP(MF)) {
- MF.getRegInfo().setPhysRegUsed(FramePtr);
- NumGPRSpills++;
- }
-
- // If stack and double are 8-byte aligned and we are spilling an odd number
- // of GPRs, spill one extra callee save GPR so we won't have to pad between
- // the integer and double callee save areas.
- unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
- if (TargetAlign == 8 && (NumGPRSpills & 1)) {
- if (CS1Spilled && !UnspilledCS1GPRs.empty()) {
- for (unsigned i = 0, e = UnspilledCS1GPRs.size(); i != e; ++i) {
- unsigned Reg = UnspilledCS1GPRs[i];
- // Don't spill high register if the function is thumb1
- if (!AFI->isThumb1OnlyFunction() ||
- isARMLowRegister(Reg) || Reg == ARM::LR) {
- MF.getRegInfo().setPhysRegUsed(Reg);
- AFI->setCSRegisterIsSpilled(Reg);
- if (!isReservedReg(MF, Reg))
- ExtraCSSpill = true;
- break;
- }
- }
- } else if (!UnspilledCS2GPRs.empty() &&
- !AFI->isThumb1OnlyFunction()) {
- unsigned Reg = UnspilledCS2GPRs.front();
- MF.getRegInfo().setPhysRegUsed(Reg);
- AFI->setCSRegisterIsSpilled(Reg);
- if (!isReservedReg(MF, Reg))
- ExtraCSSpill = true;
- }
- }
-
- // Estimate if we might need to scavenge a register at some point in order
- // to materialize a stack offset. If so, either spill one additional
- // callee-saved register or reserve a special spill slot to facilitate
- // register scavenging. Thumb1 needs a spill slot for stack pointer
- // adjustments also, even when the frame itself is small.
- if (BigStack && !ExtraCSSpill) {
- // If any non-reserved CS register isn't spilled, just spill one or two
- // extra. That should take care of it!
- unsigned NumExtras = TargetAlign / 4;
- SmallVector<unsigned, 2> Extras;
- while (NumExtras && !UnspilledCS1GPRs.empty()) {
- unsigned Reg = UnspilledCS1GPRs.back();
- UnspilledCS1GPRs.pop_back();
- if (!isReservedReg(MF, Reg) &&
- (!AFI->isThumb1OnlyFunction() || isARMLowRegister(Reg) ||
- Reg == ARM::LR)) {
- Extras.push_back(Reg);
- NumExtras--;
- }
- }
- // For non-Thumb1 functions, also check for hi-reg CS registers
- if (!AFI->isThumb1OnlyFunction()) {
- while (NumExtras && !UnspilledCS2GPRs.empty()) {
- unsigned Reg = UnspilledCS2GPRs.back();
- UnspilledCS2GPRs.pop_back();
- if (!isReservedReg(MF, Reg)) {
- Extras.push_back(Reg);
- NumExtras--;
- }
- }
- }
- if (Extras.size() && NumExtras == 0) {
- for (unsigned i = 0, e = Extras.size(); i != e; ++i) {
- MF.getRegInfo().setPhysRegUsed(Extras[i]);
- AFI->setCSRegisterIsSpilled(Extras[i]);
- }
- } else if (!AFI->isThumb1OnlyFunction()) {
- // note: Thumb1 functions spill to R12, not the stack. Reserve a slot
- // closest to SP or frame pointer.
- const TargetRegisterClass *RC = ARM::GPRRegisterClass;
- RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
- RC->getAlignment(),
- false));
- }
- }
- }
-
- if (ForceLRSpill) {
- MF.getRegInfo().setPhysRegUsed(ARM::LR);
- AFI->setCSRegisterIsSpilled(ARM::LR);
- AFI->setLRIsSpilledForFarJump(true);
- }
-}
-
-unsigned ARMBaseRegisterInfo::getRARegister() const {
- return ARM::LR;
-}
-
unsigned
ARMBaseRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
- if (hasFP(MF))
- return FramePtr;
- return ARM::SP;
-}
-
-// Provide a base+offset reference to an FI slot for debug info. It's the
-// same as what we use for resolving the code-gen references for now.
-// FIXME: This can go wrong when references are SP-relative and simple call
-// frames aren't used.
-int
-ARMBaseRegisterInfo::getFrameIndexReference(const MachineFunction &MF, int FI,
- unsigned &FrameReg) const {
- return ResolveFrameIndexReference(MF, FI, FrameReg, 0);
-}
-
-int
-ARMBaseRegisterInfo::ResolveFrameIndexReference(const MachineFunction &MF,
- int FI,
- unsigned &FrameReg,
- int SPAdj) const {
- const MachineFrameInfo *MFI = MF.getFrameInfo();
- const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- int Offset = MFI->getObjectOffset(FI) + MFI->getStackSize();
- int FPOffset = Offset - AFI->getFramePtrSpillOffset();
- bool isFixed = MFI->isFixedObjectIndex(FI);
-
- FrameReg = ARM::SP;
- Offset += SPAdj;
- if (AFI->isGPRCalleeSavedArea1Frame(FI))
- return Offset - AFI->getGPRCalleeSavedArea1Offset();
- else if (AFI->isGPRCalleeSavedArea2Frame(FI))
- return Offset - AFI->getGPRCalleeSavedArea2Offset();
- else if (AFI->isDPRCalleeSavedAreaFrame(FI))
- return Offset - AFI->getDPRCalleeSavedAreaOffset();
-
- // When dynamically realigning the stack, use the frame pointer for
- // parameters, and the stack/base pointer for locals.
- if (needsStackRealignment(MF)) {
- assert (hasFP(MF) && "dynamic stack realignment without a FP!");
- if (isFixed) {
- FrameReg = getFrameRegister(MF);
- Offset = FPOffset;
- } else if (MFI->hasVarSizedObjects()) {
- assert(hasBasePointer(MF) &&
- "VLAs and dynamic stack alignment, but missing base pointer!");
- FrameReg = BasePtr;
- }
- return Offset;
- }
-
- // If there is a frame pointer, use it when we can.
- if (hasFP(MF) && AFI->hasStackFrame()) {
- // Use frame pointer to reference fixed objects. Use it for locals if
- // there are VLAs (and thus the SP isn't reliable as a base).
- if (isFixed || (MFI->hasVarSizedObjects() && !hasBasePointer(MF))) {
- FrameReg = getFrameRegister(MF);
- return FPOffset;
- } else if (MFI->hasVarSizedObjects()) {
- assert(hasBasePointer(MF) && "missing base pointer!");
- // Try to use the frame pointer if we can, else use the base pointer
- // since it's available. This is handy for the emergency spill slot, in
- // particular.
- if (AFI->isThumb2Function()) {
- if (FPOffset >= -255 && FPOffset < 0) {
- FrameReg = getFrameRegister(MF);
- return FPOffset;
- }
- } else
- FrameReg = BasePtr;
- } else if (AFI->isThumb2Function()) {
- // In Thumb2 mode, the negative offset is very limited. Try to avoid
- // out of range references.
- if (FPOffset >= -255 && FPOffset < 0) {
- FrameReg = getFrameRegister(MF);
- return FPOffset;
- }
- } else if (Offset > (FPOffset < 0 ? -FPOffset : FPOffset)) {
- // Otherwise, use SP or FP, whichever is closer to the stack slot.
- FrameReg = getFrameRegister(MF);
- return FPOffset;
- }
- }
- // Use the base pointer if we have one.
- if (hasBasePointer(MF))
- FrameReg = BasePtr;
- return Offset;
-}
-
-int
-ARMBaseRegisterInfo::getFrameIndexOffset(const MachineFunction &MF,
- int FI) const {
- unsigned FrameReg;
- return getFrameIndexReference(MF, FI, FrameReg);
-}
-
-unsigned ARMBaseRegisterInfo::getEHExceptionRegister() const {
- llvm_unreachable("What is the exception register");
- return 0;
-}
-
-unsigned ARMBaseRegisterInfo::getEHHandlerRegister() const {
- llvm_unreachable("What is the exception handler register");
- return 0;
-}
-
-int ARMBaseRegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const {
- return ARMGenRegisterInfo::getDwarfRegNumFull(RegNum, 0);
-}
-
-unsigned ARMBaseRegisterInfo::getRegisterPairEven(unsigned Reg,
- const MachineFunction &MF) const {
- switch (Reg) {
- default: break;
- // Return 0 if either register of the pair is a special register.
- // So no R12, etc.
- case ARM::R1:
- return ARM::R0;
- case ARM::R3:
- return ARM::R2;
- case ARM::R5:
- return ARM::R4;
- case ARM::R7:
- return (isReservedReg(MF, ARM::R7) || isReservedReg(MF, ARM::R6))
- ? 0 : ARM::R6;
- case ARM::R9:
- return isReservedReg(MF, ARM::R9) ? 0 :ARM::R8;
- case ARM::R11:
- return isReservedReg(MF, ARM::R11) ? 0 : ARM::R10;
-
- case ARM::S1:
- return ARM::S0;
- case ARM::S3:
- return ARM::S2;
- case ARM::S5:
- return ARM::S4;
- case ARM::S7:
- return ARM::S6;
- case ARM::S9:
- return ARM::S8;
- case ARM::S11:
- return ARM::S10;
- case ARM::S13:
- return ARM::S12;
- case ARM::S15:
- return ARM::S14;
- case ARM::S17:
- return ARM::S16;
- case ARM::S19:
- return ARM::S18;
- case ARM::S21:
- return ARM::S20;
- case ARM::S23:
- return ARM::S22;
- case ARM::S25:
- return ARM::S24;
- case ARM::S27:
- return ARM::S26;
- case ARM::S29:
- return ARM::S28;
- case ARM::S31:
- return ARM::S30;
-
- case ARM::D1:
- return ARM::D0;
- case ARM::D3:
- return ARM::D2;
- case ARM::D5:
- return ARM::D4;
- case ARM::D7:
- return ARM::D6;
- case ARM::D9:
- return ARM::D8;
- case ARM::D11:
- return ARM::D10;
- case ARM::D13:
- return ARM::D12;
- case ARM::D15:
- return ARM::D14;
- case ARM::D17:
- return ARM::D16;
- case ARM::D19:
- return ARM::D18;
- case ARM::D21:
- return ARM::D20;
- case ARM::D23:
- return ARM::D22;
- case ARM::D25:
- return ARM::D24;
- case ARM::D27:
- return ARM::D26;
- case ARM::D29:
- return ARM::D28;
- case ARM::D31:
- return ARM::D30;
- }
+ const ARMSubtarget &STI = MF.getSubtarget<ARMSubtarget>();
+ const ARMFrameLowering *TFI = getFrameLowering(MF);
- return 0;
-}
-
-unsigned ARMBaseRegisterInfo::getRegisterPairOdd(unsigned Reg,
- const MachineFunction &MF) const {
- switch (Reg) {
- default: break;
- // Return 0 if either register of the pair is a special register.
- // So no R12, etc.
- case ARM::R0:
- return ARM::R1;
- case ARM::R2:
- return ARM::R3;
- case ARM::R4:
- return ARM::R5;
- case ARM::R6:
- return (isReservedReg(MF, ARM::R7) || isReservedReg(MF, ARM::R6))
- ? 0 : ARM::R7;
- case ARM::R8:
- return isReservedReg(MF, ARM::R9) ? 0 :ARM::R9;
- case ARM::R10:
- return isReservedReg(MF, ARM::R11) ? 0 : ARM::R11;
-
- case ARM::S0:
- return ARM::S1;
- case ARM::S2:
- return ARM::S3;
- case ARM::S4:
- return ARM::S5;
- case ARM::S6:
- return ARM::S7;
- case ARM::S8:
- return ARM::S9;
- case ARM::S10:
- return ARM::S11;
- case ARM::S12:
- return ARM::S13;
- case ARM::S14:
- return ARM::S15;
- case ARM::S16:
- return ARM::S17;
- case ARM::S18:
- return ARM::S19;
- case ARM::S20:
- return ARM::S21;
- case ARM::S22:
- return ARM::S23;
- case ARM::S24:
- return ARM::S25;
- case ARM::S26:
- return ARM::S27;
- case ARM::S28:
- return ARM::S29;
- case ARM::S30:
- return ARM::S31;
-
- case ARM::D0:
- return ARM::D1;
- case ARM::D2:
- return ARM::D3;
- case ARM::D4:
- return ARM::D5;
- case ARM::D6:
- return ARM::D7;
- case ARM::D8:
- return ARM::D9;
- case ARM::D10:
- return ARM::D11;
- case ARM::D12:
- return ARM::D13;
- case ARM::D14:
- return ARM::D15;
- case ARM::D16:
- return ARM::D17;
- case ARM::D18:
- return ARM::D19;
- case ARM::D20:
- return ARM::D21;
- case ARM::D22:
- return ARM::D23;
- case ARM::D24:
- return ARM::D25;
- case ARM::D26:
- return ARM::D27;
- case ARM::D28:
- return ARM::D29;
- case ARM::D30:
- return ARM::D31;
- }
-
- return 0;
+ if (TFI->hasFP(MF))
+ return getFramePointerReg(STI);
+ return ARM::SP;
}
/// emitLoadConstPool - Emits a load from constpool to materialize the
DebugLoc dl,
unsigned DestReg, unsigned SubIdx, int Val,
ARMCC::CondCodes Pred,
- unsigned PredReg) const {
+ unsigned PredReg, unsigned MIFlags) const {
MachineFunction &MF = *MBB.getParent();
+ const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
MachineConstantPool *ConstantPool = MF.getConstantPool();
const Constant *C =
ConstantInt::get(Type::getInt32Ty(MF.getFunction()->getContext()), Val);
BuildMI(MBB, MBBI, dl, TII.get(ARM::LDRcp))
.addReg(DestReg, getDefRegState(true), SubIdx)
.addConstantPoolIndex(Idx)
- .addImm(0).addImm(Pred).addReg(PredReg);
+ .addImm(0).addImm(Pred).addReg(PredReg)
+ .setMIFlags(MIFlags);
}
bool ARMBaseRegisterInfo::
}
bool ARMBaseRegisterInfo::
-requiresFrameIndexScavenging(const MachineFunction &MF) const {
+trackLivenessAfterRegAlloc(const MachineFunction &MF) const {
return true;
}
bool ARMBaseRegisterInfo::
-requiresVirtualBaseRegisters(const MachineFunction &MF) const {
- return EnableLocalStackAlloc;
-}
-
-// hasReservedCallFrame - Under normal circumstances, when a frame pointer is
-// not required, we reserve argument space for call sites in the function
-// immediately on entry to the current function. This eliminates the need for
-// add/sub sp brackets around call sites. Returns true if the call frame is
-// included as part of the stack frame.
-bool ARMBaseRegisterInfo::
-hasReservedCallFrame(const MachineFunction &MF) const {
- const MachineFrameInfo *FFI = MF.getFrameInfo();
- unsigned CFSize = FFI->getMaxCallFrameSize();
- // It's not always a good idea to include the call frame as part of the
- // stack frame. ARM (especially Thumb) has small immediate offset to
- // address the stack frame. So a large call frame can cause poor codegen
- // and may even makes it impossible to scavenge a register.
- if (CFSize >= ((1 << 12) - 1) / 2) // Half of imm12
- return false;
-
- return !MF.getFrameInfo()->hasVarSizedObjects();
+requiresFrameIndexScavenging(const MachineFunction &MF) const {
+ return true;
}
-// canSimplifyCallFramePseudos - If there is a reserved call frame, the
-// call frame pseudos can be simplified. Unlike most targets, having a FP
-// is not sufficient here since we still may reference some objects via SP
-// even when FP is available in Thumb2 mode.
bool ARMBaseRegisterInfo::
-canSimplifyCallFramePseudos(const MachineFunction &MF) const {
- return hasReservedCallFrame(MF) || MF.getFrameInfo()->hasVarSizedObjects();
-}
-
-static void
-emitSPUpdate(bool isARM,
- MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
- DebugLoc dl, const ARMBaseInstrInfo &TII,
- int NumBytes,
- ARMCC::CondCodes Pred = ARMCC::AL, unsigned PredReg = 0) {
- if (isARM)
- emitARMRegPlusImmediate(MBB, MBBI, dl, ARM::SP, ARM::SP, NumBytes,
- Pred, PredReg, TII);
- else
- emitT2RegPlusImmediate(MBB, MBBI, dl, ARM::SP, ARM::SP, NumBytes,
- Pred, PredReg, TII);
-}
-
-
-void ARMBaseRegisterInfo::
-eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
- MachineBasicBlock::iterator I) const {
- if (!hasReservedCallFrame(MF)) {
- // If we have alloca, convert as follows:
- // ADJCALLSTACKDOWN -> sub, sp, sp, amount
- // ADJCALLSTACKUP -> add, sp, sp, amount
- MachineInstr *Old = I;
- DebugLoc dl = Old->getDebugLoc();
- unsigned Amount = Old->getOperand(0).getImm();
- if (Amount != 0) {
- // We need to keep the stack aligned properly. To do this, we round the
- // amount of space needed for the outgoing arguments up to the next
- // alignment boundary.
- unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
- Amount = (Amount+Align-1)/Align*Align;
-
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- assert(!AFI->isThumb1OnlyFunction() &&
- "This eliminateCallFramePseudoInstr does not support Thumb1!");
- bool isARM = !AFI->isThumbFunction();
-
- // Replace the pseudo instruction with a new instruction...
- unsigned Opc = Old->getOpcode();
- int PIdx = Old->findFirstPredOperandIdx();
- ARMCC::CondCodes Pred = (PIdx == -1)
- ? ARMCC::AL : (ARMCC::CondCodes)Old->getOperand(PIdx).getImm();
- if (Opc == ARM::ADJCALLSTACKDOWN || Opc == ARM::tADJCALLSTACKDOWN) {
- // Note: PredReg is operand 2 for ADJCALLSTACKDOWN.
- unsigned PredReg = Old->getOperand(2).getReg();
- emitSPUpdate(isARM, MBB, I, dl, TII, -Amount, Pred, PredReg);
- } else {
- // Note: PredReg is operand 3 for ADJCALLSTACKUP.
- unsigned PredReg = Old->getOperand(3).getReg();
- assert(Opc == ARM::ADJCALLSTACKUP || Opc == ARM::tADJCALLSTACKUP);
- emitSPUpdate(isARM, MBB, I, dl, TII, Amount, Pred, PredReg);
- }
- }
- }
- MBB.erase(I);
+requiresVirtualBaseRegisters(const MachineFunction &MF) const {
+ return true;
}
int64_t ARMBaseRegisterInfo::
getFrameIndexInstrOffset(const MachineInstr *MI, int Idx) const {
- const TargetInstrDesc &Desc = MI->getDesc();
+ const MCInstrDesc &Desc = MI->getDesc();
unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
- int64_t InstrOffs = 0;;
+ int64_t InstrOffs = 0;
int Scale = 1;
unsigned ImmIdx = 0;
switch (AddrMode) {
}
default:
llvm_unreachable("Unsupported addressing mode!");
- break;
}
return InstrOffs * Scale;
case ARM::VLDRS: case ARM::VLDRD:
case ARM::VSTRS: case ARM::VSTRD:
case ARM::tSTRspi: case ARM::tLDRspi:
- if (ForceAllBaseRegAlloc)
- return true;
break;
default:
return false;
// Note that the incoming offset is based on the SP value at function entry,
// so it'll be negative.
MachineFunction &MF = *MI->getParent()->getParent();
+ const ARMFrameLowering *TFI = getFrameLowering(MF);
MachineFrameInfo *MFI = MF.getFrameInfo();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
// The incoming offset is relating to the SP at the start of the function,
// but when we access the local it'll be relative to the SP after local
// allocation, so adjust our SP-relative offset by that allocation size.
- Offset = -Offset;
Offset += MFI->getLocalFrameSize();
// Assume that we'll have at least some spill slots allocated.
// FIXME: This is a total SWAG number. We should run some statistics
// and pick a real one.
Offset += 128; // 128 bytes of spill slots
- // If there is a frame pointer, try using it.
+ // If there's a frame pointer and the addressing mode allows it, try using it.
// The FP is only available if there is no dynamic realignment. We
// don't know for sure yet whether we'll need that, so we guess based
// on whether there are any local variables that would trigger it.
- unsigned StackAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
- if (hasFP(MF) &&
+ unsigned StackAlign = TFI->getStackAlignment();
+ if (TFI->hasFP(MF) &&
!((MFI->getLocalFrameMaxAlign() > StackAlign) && canRealignStack(MF))) {
- if (isFrameOffsetLegal(MI, FPOffset))
+ if (isFrameOffsetLegal(MI, getFrameRegister(MF), FPOffset))
return false;
}
// If we can reference via the stack pointer, try that.
// to only disallow SP relative references in the live range of
// the VLA(s). In practice, it's unclear how much difference that
// would make, but it may be worth doing.
- if (!MFI->hasVarSizedObjects() && isFrameOffsetLegal(MI, Offset))
+ if (!MFI->hasVarSizedObjects() && isFrameOffsetLegal(MI, ARM::SP, Offset))
return false;
// The offset likely isn't legal, we want to allocate a virtual base register.
return true;
}
-/// materializeFrameBaseRegister - Insert defining instruction(s) for
-/// BaseReg to be a pointer to FrameIdx before insertion point I.
+/// materializeFrameBaseRegister - Insert defining instruction(s) for BaseReg to
+/// be a pointer to FrameIdx at the beginning of the basic block.
void ARMBaseRegisterInfo::
-materializeFrameBaseRegister(MachineBasicBlock::iterator I, unsigned BaseReg,
- int FrameIdx, int64_t Offset) const {
- ARMFunctionInfo *AFI =
-
I->getParent()->getParent()->getInfo<ARMFunctionInfo>();
+materializeFrameBaseRegister(MachineBasicBlock *MBB,
+ unsigned BaseReg, int FrameIdx,
+ int64_t Offset) const {
+
ARMFunctionInfo *AFI = MBB->getParent()->getInfo<ARMFunctionInfo>();
unsigned ADDriOpc = !AFI->isThumbFunction() ? ARM::ADDri :
- (AFI->isThumb1OnlyFunction() ? ARM::tADDrSPi : ARM::t2ADDri);
+ (AFI->isThumb1OnlyFunction() ? ARM::tADDframe : ARM::t2ADDri);
+
+ MachineBasicBlock::iterator Ins = MBB->begin();
+ DebugLoc DL; // Defaults to "unknown"
+ if (Ins != MBB->end())
+ DL = Ins->getDebugLoc();
- MachineInstrBuilder MIB =
- BuildMI(*I->getParent(), I, I->getDebugLoc(), TII.get(ADDriOpc), BaseReg)
+ const MachineFunction &MF = *MBB->getParent();
+ MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
+ const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
+ const MCInstrDesc &MCID = TII.get(ADDriOpc);
+ MRI.constrainRegClass(BaseReg, TII.getRegClass(MCID, 0, this, MF));
+
+ MachineInstrBuilder MIB = BuildMI(*MBB, Ins, DL, MCID, BaseReg)
.addFrameIndex(FrameIdx).addImm(Offset);
+
if (!AFI->isThumb1OnlyFunction())
AddDefaultCC(AddDefaultPred(MIB));
}
-void
-ARMBaseRegisterInfo::resolveFrameIndex(MachineBasicBlock::iterator I,
- unsigned BaseReg, int64_t Offset) const {
- MachineInstr &MI = *I;
+void ARMBaseRegisterInfo::resolveFrameIndex(MachineInstr &MI, unsigned BaseReg,
+ int64_t Offset) const {
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
+ const ARMBaseInstrInfo &TII =
+ *static_cast<const ARMBaseInstrInfo *>(MF.getSubtarget().getInstrInfo());
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
int Off = Offset; // ARM doesn't need the general 64-bit offsets
unsigned i = 0;
Done = rewriteT2FrameIndex(MI, i, BaseReg, Off, TII);
}
assert (Done && "Unable to resolve frame index!");
+ (void)Done;
}
-bool ARMBaseRegisterInfo::isFrameOffsetLegal(const MachineInstr *MI,
+bool ARMBaseRegisterInfo::isFrameOffsetLegal(const MachineInstr *MI, unsigned BaseReg,
int64_t Offset) const {
- const TargetInstrDesc &Desc = MI->getDesc();
+ const MCInstrDesc &Desc = MI->getDesc();
unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
unsigned i = 0;
NumBits = 8;
break;
case ARMII::AddrModeT1_s:
- NumBits = 5;
+ NumBits = (BaseReg == ARM::SP ? 8 : 5);
Scale = 4;
isSigned = false;
break;
default:
llvm_unreachable("Unsupported addressing mode!");
- break;
}
Offset += getFrameIndexInstrOffset(MI, i);
void
ARMBaseRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
- int SPAdj, RegScavenger *RS) const {
- unsigned i = 0;
+ int SPAdj, unsigned FIOperandNum,
+ RegScavenger *RS) const {
MachineInstr &MI = *II;
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
+ const ARMBaseInstrInfo &TII =
+ *static_cast<const ARMBaseInstrInfo *>(MF.getSubtarget().getInstrInfo());
+ const ARMFrameLowering *TFI = getFrameLowering(MF);
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
assert(!AFI->isThumb1OnlyFunction() &&
"This eliminateFrameIndex does not support Thumb1!");
-
- while (!MI.getOperand(i).isFI()) {
- ++i;
- assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
- }
-
- int FrameIndex = MI.getOperand(i).getIndex();
+ int FrameIndex = MI.getOperand(FIOperandNum).getIndex();
unsigned FrameReg;
- int Offset = ResolveFrameIndexReference(MF, FrameIndex, FrameReg, SPAdj);
+ int Offset = TFI->ResolveFrameIndexReference(MF, FrameIndex, FrameReg, SPAdj);
- // Special handling of dbg_value instructions.
- if (MI.isDebugValue()) {
- MI.getOperand(i). ChangeToRegister(FrameReg, false /*isDef*/);
- MI.getOperand(i+1).ChangeToImmediate(Offset);
- return;
+ // PEI::scavengeFrameVirtualRegs() cannot accurately track SPAdj because the
+ // call frame setup/destroy instructions have already been eliminated. That
+ // means the stack pointer cannot be used to access the emergency spill slot
+ // when !hasReservedCallFrame().
+#ifndef NDEBUG
+ if (RS && FrameReg == ARM::SP && RS->isScavengingFrameIndex(FrameIndex)){
+ assert(TFI->hasReservedCallFrame(MF) &&
+ "Cannot use SP to access the emergency spill slot in "
+ "functions without a reserved call frame");
+ assert(!MF.getFrameInfo()->hasVarSizedObjects() &&
+ "Cannot use SP to access the emergency spill slot in "
+ "functions with variable sized frame objects");
}
+#endif // NDEBUG
+
+ assert(!MI.isDebugValue() && "DBG_VALUEs should be handled in target-independent code");
// Modify MI as necessary to handle as much of 'Offset' as possible
bool Done = false;
if (!AFI->isThumbFunction())
- Done = rewriteARMFrameIndex(MI, i, FrameReg, Offset, TII);
+ Done = rewriteARMFrameIndex(MI, FIOperandNum, FrameReg, Offset, TII);
else {
assert(AFI->isThumb2Function());
- Done = rewriteT2FrameIndex(MI, i, FrameReg, Offset, TII);
+ Done = rewriteT2FrameIndex(MI, FIOperandNum, FrameReg, Offset, TII);
}
if (Done)
return;
unsigned PredReg = (PIdx == -1) ? 0 : MI.getOperand(PIdx+1).getReg();
if (Offset == 0)
// Must be addrmode4/6.
- MI.getOperand(i).ChangeToRegister(FrameReg, false, false, false);
+ MI.getOperand(FIOperandNum).ChangeToRegister(FrameReg, false, false, false);
else {
- ScratchReg = MF.getRegInfo().createVirtualRegister(ARM::GPRRegisterClass);
+ ScratchReg = MF.getRegInfo().createVirtualRegister(&ARM::GPRRegClass);
if (!AFI->isThumbFunction())
emitARMRegPlusImmediate(MBB, II, MI.getDebugLoc(), ScratchReg, FrameReg,
Offset, Pred, PredReg, TII);
emitT2RegPlusImmediate(MBB, II, MI.getDebugLoc(), ScratchReg, FrameReg,
Offset, Pred, PredReg, TII);
}
- MI.getOperand(i).ChangeToRegister(ScratchReg, false, false, true);
- }
-}
-
-/// Move iterator past the next bunch of callee save load / store ops for
-/// the particular spill area (1: integer area 1, 2: integer area 2,
-/// 3: fp area, 0: don't care).
-static void movePastCSLoadStoreOps(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MBBI,
- int Opc1, int Opc2, unsigned Area,
- const ARMSubtarget &STI) {
- while (MBBI != MBB.end() &&
- ((MBBI->getOpcode() == Opc1) || (MBBI->getOpcode() == Opc2)) &&
- MBBI->getOperand(1).isFI()) {
- if (Area != 0) {
- bool Done = false;
- unsigned Category = 0;
- switch (MBBI->getOperand(0).getReg()) {
- case ARM::R4: case ARM::R5: case ARM::R6: case ARM::R7:
- case ARM::LR:
- Category = 1;
- break;
- case ARM::R8: case ARM::R9: case ARM::R10: case ARM::R11:
- Category = STI.isTargetDarwin() ? 2 : 1;
- break;
- case ARM::D8: case ARM::D9: case ARM::D10: case ARM::D11:
- case ARM::D12: case ARM::D13: case ARM::D14: case ARM::D15:
- Category = 3;
- break;
- default:
- Done = true;
- break;
- }
- if (Done || Category != Area)
- break;
- }
-
- ++MBBI;
- }
-}
-
-void ARMBaseRegisterInfo::
-emitPrologue(MachineFunction &MF) const {
- MachineBasicBlock &MBB = MF.front();
- MachineBasicBlock::iterator MBBI = MBB.begin();
- MachineFrameInfo *MFI = MF.getFrameInfo();
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- assert(!AFI->isThumb1OnlyFunction() &&
- "This emitPrologue does not support Thumb1!");
- bool isARM = !AFI->isThumbFunction();
- unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
- unsigned NumBytes = MFI->getStackSize();
- const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
- DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
-
- // Determine the sizes of each callee-save spill areas and record which frame
- // belongs to which callee-save spill areas.
- unsigned GPRCS1Size = 0, GPRCS2Size = 0, DPRCSSize = 0;
- int FramePtrSpillFI = 0;
-
- // Allocate the vararg register save area. This is not counted in NumBytes.
- if (VARegSaveSize)
- emitSPUpdate(isARM, MBB, MBBI, dl, TII, -VARegSaveSize);
-
- if (!AFI->hasStackFrame()) {
- if (NumBytes != 0)
- emitSPUpdate(isARM, MBB, MBBI, dl, TII, -NumBytes);
- return;
- }
-
- for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
- unsigned Reg = CSI[i].getReg();
- int FI = CSI[i].getFrameIdx();
- switch (Reg) {
- case ARM::R4:
- case ARM::R5:
- case ARM::R6:
- case ARM::R7:
- case ARM::LR:
- if (Reg == FramePtr)
- FramePtrSpillFI = FI;
- AFI->addGPRCalleeSavedArea1Frame(FI);
- GPRCS1Size += 4;
- break;
- case ARM::R8:
- case ARM::R9:
- case ARM::R10:
- case ARM::R11:
- if (Reg == FramePtr)
- FramePtrSpillFI = FI;
- if (STI.isTargetDarwin()) {
- AFI->addGPRCalleeSavedArea2Frame(FI);
- GPRCS2Size += 4;
- } else {
- AFI->addGPRCalleeSavedArea1Frame(FI);
- GPRCS1Size += 4;
- }
- break;
- default:
- AFI->addDPRCalleeSavedAreaFrame(FI);
- DPRCSSize += 8;
- }
- }
-
- // Build the new SUBri to adjust SP for integer callee-save spill area 1.
- emitSPUpdate(isARM, MBB, MBBI, dl, TII, -GPRCS1Size);
- movePastCSLoadStoreOps(MBB, MBBI, ARM::STRi12, ARM::t2STRi12, 1, STI);
-
- // Set FP to point to the stack slot that contains the previous FP.
- // For Darwin, FP is R7, which has now been stored in spill area 1.
- // Otherwise, if this is not Darwin, all the callee-saved registers go
- // into spill area 1, including the FP in R11. In either case, it is
- // now safe to emit this assignment.
- bool HasFP = hasFP(MF);
- if (HasFP) {
- unsigned ADDriOpc = !AFI->isThumbFunction() ? ARM::ADDri : ARM::t2ADDri;
- MachineInstrBuilder MIB =
- BuildMI(MBB, MBBI, dl, TII.get(ADDriOpc), FramePtr)
- .addFrameIndex(FramePtrSpillFI).addImm(0);
- AddDefaultCC(AddDefaultPred(MIB));
- }
-
- // Build the new SUBri to adjust SP for integer callee-save spill area 2.
- emitSPUpdate(isARM, MBB, MBBI, dl, TII, -GPRCS2Size);
-
- // Build the new SUBri to adjust SP for FP callee-save spill area.
- movePastCSLoadStoreOps(MBB, MBBI, ARM::STRi12, ARM::t2STRi12, 2, STI);
- emitSPUpdate(isARM, MBB, MBBI, dl, TII, -DPRCSSize);
-
- // Determine starting offsets of spill areas.
- unsigned DPRCSOffset = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize);
- unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
- unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
- if (HasFP)
- AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) +
- NumBytes);
- AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset);
- AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
- AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
-
- movePastCSLoadStoreOps(MBB, MBBI, ARM::VSTRD, 0, 3, STI);
- NumBytes = DPRCSOffset;
- if (NumBytes) {
- // Adjust SP after all the callee-save spills.
- emitSPUpdate(isARM, MBB, MBBI, dl, TII, -NumBytes);
- if (HasFP)
- AFI->setShouldRestoreSPFromFP(true);
- }
-
- if (STI.isTargetELF() && hasFP(MF)) {
- MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() -
- AFI->getFramePtrSpillOffset());
- AFI->setShouldRestoreSPFromFP(true);
- }
-
- AFI->setGPRCalleeSavedArea1Size(GPRCS1Size);
- AFI->setGPRCalleeSavedArea2Size(GPRCS2Size);
- AFI->setDPRCalleeSavedAreaSize(DPRCSSize);
-
- // If we need dynamic stack realignment, do it here. Be paranoid and make
- // sure if we also have VLAs, we have a base pointer for frame access.
- if (needsStackRealignment(MF)) {
- unsigned MaxAlign = MFI->getMaxAlignment();
- assert (!AFI->isThumb1OnlyFunction());
- if (!AFI->isThumbFunction()) {
- // Emit bic sp, sp, MaxAlign
- AddDefaultCC(AddDefaultPred(BuildMI(MBB, MBBI, dl,
- TII.get(ARM::BICri), ARM::SP)
- .addReg(ARM::SP, RegState::Kill)
- .addImm(MaxAlign-1)));
- } else {
- // We cannot use sp as source/dest register here, thus we're emitting the
- // following sequence:
- // mov r4, sp
- // bic r4, r4, MaxAlign
- // mov sp, r4
- // FIXME: It will be better just to find spare register here.
- BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVgpr2tgpr), ARM::R4)
- .addReg(ARM::SP, RegState::Kill);
- AddDefaultCC(AddDefaultPred(BuildMI(MBB, MBBI, dl,
- TII.get(ARM::t2BICri), ARM::R4)
- .addReg(ARM::R4, RegState::Kill)
- .addImm(MaxAlign-1)));
- BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVtgpr2gpr), ARM::SP)
- .addReg(ARM::R4, RegState::Kill);
- }
+ // Update the original instruction to use the scratch register.
+ MI.getOperand(FIOperandNum).ChangeToRegister(ScratchReg, false, false,true);
+ }
+}
+
+bool ARMBaseRegisterInfo::shouldCoalesce(MachineInstr *MI,
+ const TargetRegisterClass *SrcRC,
+ unsigned SubReg,
+ const TargetRegisterClass *DstRC,
+ unsigned DstSubReg,
+ const TargetRegisterClass *NewRC) const {
+ auto MBB = MI->getParent();
+ auto MF = MBB->getParent();
+ const MachineRegisterInfo &MRI = MF->getRegInfo();
+ // If not copying into a sub-register this should be ok because we shouldn't
+ // need to split the reg.
+ if (!DstSubReg)
+ return true;
+ // Small registers don't frequently cause a problem, so we can coalesce them.
+ if (NewRC->getSize() < 32 && DstRC->getSize() < 32 && SrcRC->getSize() < 32)
+ return true;
- AFI->setShouldRestoreSPFromFP(true);
- }
+ auto NewRCWeight =
+ MRI.getTargetRegisterInfo()->getRegClassWeight(NewRC);
+ auto SrcRCWeight =
+ MRI.getTargetRegisterInfo()->getRegClassWeight(SrcRC);
+ auto DstRCWeight =
+ MRI.getTargetRegisterInfo()->getRegClassWeight(DstRC);
+ // If the source register class is more expensive than the destination, the
+ // coalescing is probably profitable.
+ if (SrcRCWeight.RegWeight > NewRCWeight.RegWeight)
+ return true;
+ if (DstRCWeight.RegWeight > NewRCWeight.RegWeight)
+ return true;
- // If we need a base pointer, set it up here. It's whatever the value
- // of the stack pointer is at this point. Any variable size objects
- // will be allocated after this, so we can still use the base pointer
- // to reference locals.
- if (hasBasePointer(MF)) {
- if (isARM)
- BuildMI(MBB, MBBI, dl, TII.get(ARM::MOVr), BasePtr)
- .addReg(ARM::SP)
- .addImm((unsigned)ARMCC::AL).addReg(0).addReg(0);
- else
- BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVgpr2gpr), BasePtr)
- .addReg(ARM::SP);
+ // If the register allocator isn't constrained, we can always allow coalescing
+ // unfortunately we don't know yet if we will be constrained.
+ // The goal of this heuristic is to restrict how many expensive registers
+ // we allow to coalesce in a given basic block.
+ auto AFI = MF->getInfo<ARMFunctionInfo>();
+ auto It = AFI->getCoalescedWeight(MBB);
+
+ DEBUG(dbgs() << "\tARM::shouldCoalesce - Coalesced Weight: "
+ << It->second << "\n");
+ DEBUG(dbgs() << "\tARM::shouldCoalesce - Reg Weight: "
+ << NewRCWeight.RegWeight << "\n");
+
+ // This number is the largest round number that which meets the criteria:
+ // (1) addresses PR18825
+ // (2) generates better code in some test cases (like vldm-shed-a9.ll)
+ // (3) Doesn't regress any test cases (in-tree, test-suite, and SPEC)
+ // In practice the SizeMultiplier will only factor in for straight line code
+ // that uses a lot of NEON vectors, which isn't terribly common.
+ unsigned SizeMultiplier = MBB->size()/100;
+ SizeMultiplier = SizeMultiplier ? SizeMultiplier : 1;
+ if (It->second < NewRCWeight.WeightLimit * SizeMultiplier) {
+ It->second += NewRCWeight.RegWeight;
+ return true;
}
-
- // If the frame has variable sized objects then the epilogue must restore
- // the sp from fp.
- if (!AFI->shouldRestoreSPFromFP() && MFI->hasVarSizedObjects())
- AFI->setShouldRestoreSPFromFP(true);
-}
-
-static bool isCalleeSavedRegister(unsigned Reg, const unsigned *CSRegs) {
- for (unsigned i = 0; CSRegs[i]; ++i)
- if (Reg == CSRegs[i])
- return true;
return false;
}
-
-static bool isCSRestore(MachineInstr *MI,
- const ARMBaseInstrInfo &TII,
- const unsigned *CSRegs) {
- return ((MI->getOpcode() == (int)ARM::VLDRD ||
- MI->getOpcode() == (int)ARM::LDRi12 ||
- MI->getOpcode() == (int)ARM::t2LDRi12) &&
- MI->getOperand(1).isFI() &&
- isCalleeSavedRegister(MI->getOperand(0).getReg(), CSRegs));
-}
-
-void ARMBaseRegisterInfo::
-emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const {
- MachineBasicBlock::iterator MBBI = prior(MBB.end());
- assert(MBBI->getDesc().isReturn() &&
- "Can only insert epilog into returning blocks");
- unsigned RetOpcode = MBBI->getOpcode();
- DebugLoc dl = MBBI->getDebugLoc();
- MachineFrameInfo *MFI = MF.getFrameInfo();
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- assert(!AFI->isThumb1OnlyFunction() &&
- "This emitEpilogue does not support Thumb1!");
- bool isARM = !AFI->isThumbFunction();
-
- unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
- int NumBytes = (int)MFI->getStackSize();
-
- if (!AFI->hasStackFrame()) {
- if (NumBytes != 0)
- emitSPUpdate(isARM, MBB, MBBI, dl, TII, NumBytes);
- } else {
- // Unwind MBBI to point to first LDR / VLDRD.
- const unsigned *CSRegs = getCalleeSavedRegs();
- if (MBBI != MBB.begin()) {
- do
- --MBBI;
- while (MBBI != MBB.begin() && isCSRestore(MBBI, TII, CSRegs));
- if (!isCSRestore(MBBI, TII, CSRegs))
- ++MBBI;
- }
-
- // Move SP to start of FP callee save spill area.
- NumBytes -= (AFI->getGPRCalleeSavedArea1Size() +
- AFI->getGPRCalleeSavedArea2Size() +
- AFI->getDPRCalleeSavedAreaSize());
-
- // Reset SP based on frame pointer only if the stack frame extends beyond
- // frame pointer stack slot or target is ELF and the function has FP.
- if (AFI->shouldRestoreSPFromFP()) {
- NumBytes = AFI->getFramePtrSpillOffset() - NumBytes;
- if (NumBytes) {
- if (isARM)
- emitARMRegPlusImmediate(MBB, MBBI, dl, ARM::SP, FramePtr, -NumBytes,
- ARMCC::AL, 0, TII);
- else
- emitT2RegPlusImmediate(MBB, MBBI, dl, ARM::SP, FramePtr, -NumBytes,
- ARMCC::AL, 0, TII);
- } else {
- // Thumb2 or ARM.
- if (isARM)
- BuildMI(MBB, MBBI, dl, TII.get(ARM::MOVr), ARM::SP)
- .addReg(FramePtr).addImm((unsigned)ARMCC::AL).addReg(0).addReg(0);
- else
- BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVgpr2gpr), ARM::SP)
- .addReg(FramePtr);
- }
- } else if (NumBytes)
- emitSPUpdate(isARM, MBB, MBBI, dl, TII, NumBytes);
-
- // Move SP to start of integer callee save spill area 2.
- movePastCSLoadStoreOps(MBB, MBBI, ARM::VLDRD, 0, 3, STI);
- emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getDPRCalleeSavedAreaSize());
-
- // Move SP to start of integer callee save spill area 1.
- movePastCSLoadStoreOps(MBB, MBBI, ARM::LDRi12, ARM::t2LDRi12, 2, STI);
- emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getGPRCalleeSavedArea2Size());
-
- // Move SP to SP upon entry to the function.
- movePastCSLoadStoreOps(MBB, MBBI, ARM::LDRi12, ARM::t2LDRi12, 1, STI);
- emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getGPRCalleeSavedArea1Size());
- }
-
- if (RetOpcode == ARM::TCRETURNdi || RetOpcode == ARM::TCRETURNdiND ||
- RetOpcode == ARM::TCRETURNri || RetOpcode == ARM::TCRETURNriND) {
- // Tail call return: adjust the stack pointer and jump to callee.
- MBBI = prior(MBB.end());
- MachineOperand &JumpTarget = MBBI->getOperand(0);
-
- // Jump to label or value in register.
- if (RetOpcode == ARM::TCRETURNdi) {
- BuildMI(MBB, MBBI, dl,
- TII.get(STI.isThumb() ? ARM::TAILJMPdt : ARM::TAILJMPd)).
- addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset(),
- JumpTarget.getTargetFlags());
- } else if (RetOpcode == ARM::TCRETURNdiND) {
- BuildMI(MBB, MBBI, dl,
- TII.get(STI.isThumb() ? ARM::TAILJMPdNDt : ARM::TAILJMPdND)).
- addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset(),
- JumpTarget.getTargetFlags());
- } else if (RetOpcode == ARM::TCRETURNri) {
- BuildMI(MBB, MBBI, dl, TII.get(ARM::TAILJMPr)).
- addReg(JumpTarget.getReg(), RegState::Kill);
- } else if (RetOpcode == ARM::TCRETURNriND) {
- BuildMI(MBB, MBBI, dl, TII.get(ARM::TAILJMPrND)).
- addReg(JumpTarget.getReg(), RegState::Kill);
- }
-
- MachineInstr *NewMI = prior(MBBI);
- for (unsigned i = 1, e = MBBI->getNumOperands(); i != e; ++i)
- NewMI->addOperand(MBBI->getOperand(i));
-
- // Delete the pseudo instruction TCRETURN.
- MBB.erase(MBBI);
- }
-
- if (VARegSaveSize)
- emitSPUpdate(isARM, MBB, MBBI, dl, TII, VARegSaveSize);
-}
-
-#include "ARMGenRegisterInfo.inc"
projects / oota-llvm.git / blobdiff