//===----------------------------------------------------------------------===//
#include "MipsFrameLowering.h"
+#include "MCTargetDesc/MipsBaseInfo.h"
#include "MipsAnalyzeImmediate.h"
#include "MipsInstrInfo.h"
#include "MipsMachineFunction.h"
-#include "MCTargetDesc/MipsBaseInfo.h"
-#include "llvm/Function.h"
+#include "MipsTargetMachine.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/Target/TargetData.h"
-#include "llvm/Target/TargetOptions.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/Function.h"
#include "llvm/Support/CommandLine.h"
+#include "llvm/Target/TargetOptions.h"
using namespace llvm;
//
//===----------------------------------------------------------------------===//
+const MipsFrameLowering *MipsFrameLowering::create(const MipsSubtarget &ST) {
+ if (ST.inMips16Mode())
+ return llvm::createMips16FrameLowering(ST);
+
+ return llvm::createMipsSEFrameLowering(ST);
+}
+
// 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.
+// pointer register. This is true if the function has variable sized allocas,
+// if it needs dynamic stack realignment, if frame pointer elimination is
+// disabled, or if the frame address is taken.
bool MipsFrameLowering::hasFP(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
- return MF.getTarget().Options.DisableFramePointerElim(MF) ||
- MFI->hasVarSizedObjects() || MFI->isFrameAddressTaken();
-}
+ const TargetRegisterInfo *TRI = STI.getRegisterInfo();
-bool MipsFrameLowering::targetHandlesStackFrameRounding() const {
- return true;
+ return MF.getTarget().Options.DisableFramePointerElim(MF) ||
+ MFI->hasVarSizedObjects() || MFI->isFrameAddressTaken() ||
+ TRI->needsStackRealignment(MF);
}
-// Build an instruction sequence to load an immediate that is too large to fit
-// in 16-bit and add the result to Reg.
-static void expandLargeImm(unsigned Reg, int64_t Imm, bool IsN64,
- const MipsInstrInfo &TII, MachineBasicBlock& MBB,
- MachineBasicBlock::iterator II, DebugLoc DL) {
- unsigned LUi = IsN64 ? Mips::LUi64 : Mips::LUi;
- unsigned ADDu = IsN64 ? Mips::DADDu : Mips::ADDu;
- unsigned ZEROReg = IsN64 ? Mips::ZERO_64 : Mips::ZERO;
- unsigned ATReg = IsN64 ? Mips::AT_64 : Mips::AT;
- MipsAnalyzeImmediate AnalyzeImm;
- const MipsAnalyzeImmediate::InstSeq &Seq =
- AnalyzeImm.Analyze(Imm, IsN64 ? 64 : 32, false /* LastInstrIsADDiu */);
- MipsAnalyzeImmediate::InstSeq::const_iterator Inst = Seq.begin();
-
- // The first instruction can be a LUi, which is different from other
- // instructions (ADDiu, ORI and SLL) in that it does not have a register
- // operand.
- if (Inst->Opc == LUi)
- BuildMI(MBB, II, DL, TII.get(LUi), ATReg)
- .addImm(SignExtend64<16>(Inst->ImmOpnd));
- else
- BuildMI(MBB, II, DL, TII.get(Inst->Opc), ATReg).addReg(ZEROReg)
- .addImm(SignExtend64<16>(Inst->ImmOpnd));
-
- // Build the remaining instructions in Seq.
- for (++Inst; Inst != Seq.end(); ++Inst)
- BuildMI(MBB, II, DL, TII.get(Inst->Opc), ATReg).addReg(ATReg)
- .addImm(SignExtend64<16>(Inst->ImmOpnd));
+bool MipsFrameLowering::hasBP(const MachineFunction &MF) const {
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+ const TargetRegisterInfo *TRI = STI.getRegisterInfo();
- BuildMI(MBB, II, DL, TII.get(ADDu), Reg).addReg(Reg).addReg(ATReg);
+ return MFI->hasVarSizedObjects() && TRI->needsStackRealignment(MF);
}
-void MipsFrameLowering::emitPrologue(MachineFunction &MF) const {
- MachineBasicBlock &MBB = MF.front();
- MachineFrameInfo *MFI = MF.getFrameInfo();
- MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
- const MipsRegisterInfo *RegInfo =
- static_cast<const MipsRegisterInfo*>(MF.getTarget().getRegisterInfo());
- const MipsInstrInfo &TII =
- *static_cast<const MipsInstrInfo*>(MF.getTarget().getInstrInfo());
- MachineBasicBlock::iterator MBBI = MBB.begin();
- DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
- unsigned SP = STI.isABI_N64() ? Mips::SP_64 : Mips::SP;
- unsigned FP = STI.isABI_N64() ? Mips::FP_64 : Mips::FP;
- unsigned ZERO = STI.isABI_N64() ? Mips::ZERO_64 : Mips::ZERO;
- unsigned ADDu = STI.isABI_N64() ? Mips::DADDu : Mips::ADDu;
- unsigned ADDiu = STI.isABI_N64() ? Mips::DADDiu : Mips::ADDiu;
-
- // First, compute final stack size.
- unsigned StackAlign = getStackAlignment();
- uint64_t StackSize =
- RoundUpToAlignment(MipsFI->getMaxCallFrameSize(), StackAlign) +
- RoundUpToAlignment(MFI->getStackSize(), StackAlign);
-
- // Update stack size
- MFI->setStackSize(StackSize);
-
- // No need to allocate space on the stack.
- if (StackSize == 0 && !MFI->adjustsStack()) return;
-
- MachineModuleInfo &MMI = MF.getMMI();
- std::vector<MachineMove> &Moves = MMI.getFrameMoves();
- MachineLocation DstML, SrcML;
-
- // Adjust stack.
- if (isInt<16>(-StackSize)) // addi sp, sp, (-stacksize)
- BuildMI(MBB, MBBI, dl, TII.get(ADDiu), SP).addReg(SP).addImm(-StackSize);
- else { // Expand immediate that doesn't fit in 16-bit.
- MipsFI->setEmitNOAT();
- expandLargeImm(SP, -StackSize, STI.isABI_N64(), TII, MBB, MBBI, dl);
- }
-
- // emit ".cfi_def_cfa_offset StackSize"
- MCSymbol *AdjustSPLabel = MMI.getContext().CreateTempSymbol();
- BuildMI(MBB, MBBI, dl,
- TII.get(TargetOpcode::PROLOG_LABEL)).addSym(AdjustSPLabel);
- DstML = MachineLocation(MachineLocation::VirtualFP);
- SrcML = MachineLocation(MachineLocation::VirtualFP, -StackSize);
- Moves.push_back(MachineMove(AdjustSPLabel, DstML, SrcML));
-
- const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
-
- if (CSI.size()) {
- // Find the instruction past the last instruction that saves a callee-saved
- // register to the stack.
- for (unsigned i = 0; i < CSI.size(); ++i)
- ++MBBI;
-
- // Iterate over list of callee-saved registers and emit .cfi_offset
- // directives.
- MCSymbol *CSLabel = MMI.getContext().CreateTempSymbol();
- BuildMI(MBB, MBBI, dl,
- TII.get(TargetOpcode::PROLOG_LABEL)).addSym(CSLabel);
-
- for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
- E = CSI.end(); I != E; ++I) {
- int64_t Offset = MFI->getObjectOffset(I->getFrameIdx());
- unsigned Reg = I->getReg();
-
- // If Reg is a double precision register, emit two cfa_offsets,
- // one for each of the paired single precision registers.
- if (Mips::AFGR64RegClass.contains(Reg)) {
- MachineLocation DstML0(MachineLocation::VirtualFP, Offset);
- MachineLocation DstML1(MachineLocation::VirtualFP, Offset + 4);
- MachineLocation SrcML0(RegInfo->getSubReg(Reg, Mips::sub_fpeven));
- MachineLocation SrcML1(RegInfo->getSubReg(Reg, Mips::sub_fpodd));
-
- if (!STI.isLittle())
- std::swap(SrcML0, SrcML1);
+uint64_t MipsFrameLowering::estimateStackSize(const MachineFunction &MF) const {
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+ const TargetRegisterInfo &TRI = *STI.getRegisterInfo();
- Moves.push_back(MachineMove(CSLabel, DstML0, SrcML0));
- Moves.push_back(MachineMove(CSLabel, DstML1, SrcML1));
- } else {
- // Reg is either in CPURegs or FGR32.
- DstML = MachineLocation(MachineLocation::VirtualFP, Offset);
- SrcML = MachineLocation(Reg);
- Moves.push_back(MachineMove(CSLabel, DstML, SrcML));
- }
- }
- }
+ int64_t Offset = 0;
- // if framepointer enabled, set it to point to the stack pointer.
- if (hasFP(MF)) {
- // Insert instruction "move $fp, $sp" at this location.
- BuildMI(MBB, MBBI, dl, TII.get(ADDu), FP).addReg(SP).addReg(ZERO);
+ // Iterate over fixed sized objects.
+ for (int I = MFI->getObjectIndexBegin(); I != 0; ++I)
+ Offset = std::max(Offset, -MFI->getObjectOffset(I));
- // emit ".cfi_def_cfa_register $fp"
- MCSymbol *SetFPLabel = MMI.getContext().CreateTempSymbol();
- BuildMI(MBB, MBBI, dl,
- TII.get(TargetOpcode::PROLOG_LABEL)).addSym(SetFPLabel);
- DstML = MachineLocation(FP);
- SrcML = MachineLocation(MachineLocation::VirtualFP);
- Moves.push_back(MachineMove(SetFPLabel, DstML, SrcML));
+ // Conservatively assume all callee-saved registers will be saved.
+ for (const MCPhysReg *R = TRI.getCalleeSavedRegs(&MF); *R; ++R) {
+ unsigned Size = TRI.getMinimalPhysRegClass(*R)->getSize();
+ Offset = RoundUpToAlignment(Offset + Size, Size);
}
-}
-
-void MipsFrameLowering::emitEpilogue(MachineFunction &MF,
- MachineBasicBlock &MBB) const {
- MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
- MachineFrameInfo *MFI = MF.getFrameInfo();
- const MipsInstrInfo &TII =
- *static_cast<const MipsInstrInfo*>(MF.getTarget().getInstrInfo());
- DebugLoc dl = MBBI->getDebugLoc();
- unsigned SP = STI.isABI_N64() ? Mips::SP_64 : Mips::SP;
- unsigned FP = STI.isABI_N64() ? Mips::FP_64 : Mips::FP;
- unsigned ZERO = STI.isABI_N64() ? Mips::ZERO_64 : Mips::ZERO;
- unsigned ADDu = STI.isABI_N64() ? Mips::DADDu : Mips::ADDu;
- unsigned ADDiu = STI.isABI_N64() ? Mips::DADDiu : Mips::ADDiu;
- // if framepointer enabled, restore the stack pointer.
- if (hasFP(MF)) {
- // Find the first instruction that restores a callee-saved register.
- MachineBasicBlock::iterator I = MBBI;
+ unsigned MaxAlign = MFI->getMaxAlignment();
- for (unsigned i = 0; i < MFI->getCalleeSavedInfo().size(); ++i)
- --I;
+ // Check that MaxAlign is not zero if there is a stack object that is not a
+ // callee-saved spill.
+ assert(!MFI->getObjectIndexEnd() || MaxAlign);
- // Insert instruction "move $sp, $fp" at this location.
- BuildMI(MBB, I, dl, TII.get(ADDu), SP).addReg(FP).addReg(ZERO);
- }
-
- // Get the number of bytes from FrameInfo
- uint64_t StackSize = MFI->getStackSize();
+ // Iterate over other objects.
+ for (unsigned I = 0, E = MFI->getObjectIndexEnd(); I != E; ++I)
+ Offset = RoundUpToAlignment(Offset + MFI->getObjectSize(I), MaxAlign);
- if (!StackSize)
- return;
+ // Call frame.
+ if (MFI->adjustsStack() && hasReservedCallFrame(MF))
+ Offset = RoundUpToAlignment(Offset + MFI->getMaxCallFrameSize(),
+ std::max(MaxAlign, getStackAlignment()));
- // Adjust stack.
- if (isInt<16>(StackSize)) // addi sp, sp, (-stacksize)
- BuildMI(MBB, MBBI, dl, TII.get(ADDiu), SP).addReg(SP).addImm(StackSize);
- else // Expand immediate that doesn't fit in 16-bit.
- expandLargeImm(SP, StackSize, STI.isABI_N64(), TII, MBB, MBBI, dl);
+ return RoundUpToAlignment(Offset, getStackAlignment());
}
+// Eliminate ADJCALLSTACKDOWN, ADJCALLSTACKUP pseudo instructions
void MipsFrameLowering::
-processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
- RegScavenger *RS) const {
- MachineRegisterInfo& MRI = MF.getRegInfo();
- unsigned FP = STI.isABI_N64() ? Mips::FP_64 : Mips::FP;
+eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator I) const {
+ unsigned SP = STI.getABI().IsN64() ? Mips::SP_64 : Mips::SP;
- // FIXME: remove this code if register allocator can correctly mark
- // $fp and $ra used or unused.
+ if (!hasReservedCallFrame(MF)) {
+ int64_t Amount = I->getOperand(0).getImm();
+ if (I->getOpcode() == Mips::ADJCALLSTACKDOWN)
+ Amount = -Amount;
- // Mark $fp and $ra as used or unused.
- if (hasFP(MF))
- MRI.setPhysRegUsed(FP);
-
- // The register allocator might determine $ra is used after seeing
- // instruction "jr $ra", but we do not want PrologEpilogInserter to insert
- // instructions to save/restore $ra unless there is a function call.
- // To correct this, $ra is explicitly marked unused if there is no
- // function call.
- if (MF.getFrameInfo()->hasCalls())
- MRI.setPhysRegUsed(Mips::RA);
- else {
- MRI.setPhysRegUnused(Mips::RA);
- MRI.setPhysRegUnused(Mips::RA_64);
+ STI.getInstrInfo()->adjustStackPtr(SP, Amount, MBB, I);
}
+
+ MBB.erase(I);
}