diff options
Diffstat (limited to 'lib/Target/Mips/MipsRegisterInfo.cpp')
| -rw-r--r-- | lib/Target/Mips/MipsRegisterInfo.cpp | 287 |
1 files changed, 5 insertions, 282 deletions
diff --git a/lib/Target/Mips/MipsRegisterInfo.cpp b/lib/Target/Mips/MipsRegisterInfo.cpp index 69436d2..3719e58 100644 --- a/lib/Target/Mips/MipsRegisterInfo.cpp +++ b/lib/Target/Mips/MipsRegisterInfo.cpp @@ -25,7 +25,7 @@ #include "llvm/CodeGen/MachineFunction.h" #include "llvm/CodeGen/MachineFrameInfo.h" #include "llvm/CodeGen/MachineLocation.h" -#include "llvm/Target/TargetFrameInfo.h" +#include "llvm/Target/TargetFrameLowering.h" #include "llvm/Target/TargetMachine.h" #include "llvm/Target/TargetOptions.h" #include "llvm/Target/TargetInstrInfo.h" @@ -117,8 +117,7 @@ getCalleeSavedRegs(const MachineFunction *MF) const } BitVector MipsRegisterInfo:: -getReservedRegs(const MachineFunction &MF) const -{ +getReservedRegs(const MachineFunction &MF) const { BitVector Reserved(getNumRegs()); Reserved.set(Mips::ZERO); Reserved.set(Mips::AT); @@ -137,184 +136,6 @@ getReservedRegs(const MachineFunction &MF) const return Reserved; } -//===----------------------------------------------------------------------===// -// -// Stack Frame Processing methods -// +----------------------------+ -// -// The stack is allocated decrementing the stack pointer on -// the first instruction of a function prologue. Once decremented, -// all stack references are done thought a positive offset -// from the stack/frame pointer, so the stack is considering -// to grow up! Otherwise terrible hacks would have to be made -// to get this stack ABI compliant :) -// -// The stack frame required by the ABI (after call): -// Offset -// -// 0 ---------- -// 4 Args to pass -// . saved $GP (used in PIC) -// . Alloca allocations -// . Local Area -// . CPU "Callee Saved" Registers -// . saved FP -// . saved RA -// . FPU "Callee Saved" Registers -// StackSize ----------- -// -// Offset - offset from sp after stack allocation on function prologue -// -// The sp is the stack pointer subtracted/added from the stack size -// at the Prologue/Epilogue -// -// References to the previous stack (to obtain arguments) are done -// with offsets that exceeds the stack size: (stacksize+(4*(num_arg-1)) -// -// Examples: -// - reference to the actual stack frame -// for any local area var there is smt like : FI >= 0, StackOffset: 4 -// sw REGX, 4(SP) -// -// - reference to previous stack frame -// suppose there's a load to the 5th arguments : FI < 0, StackOffset: 16. -// The emitted instruction will be something like: -// lw REGX, 16+StackSize(SP) -// -// Since the total stack size is unknown on LowerFormalArguments, all -// stack references (ObjectOffset) created to reference the function -// arguments, are negative numbers. This way, on eliminateFrameIndex it's -// possible to detect those references and the offsets are adjusted to -// their real location. -// -//===----------------------------------------------------------------------===// - -void MipsRegisterInfo::adjustMipsStackFrame(MachineFunction &MF) const -{ - MachineFrameInfo *MFI = MF.getFrameInfo(); - MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>(); - const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo(); - unsigned StackAlign = MF.getTarget().getFrameInfo()->getStackAlignment(); - unsigned RegSize = Subtarget.isGP32bit() ? 4 : 8; - bool HasGP = MipsFI->needGPSaveRestore(); - - // Min and Max CSI FrameIndex. - int MinCSFI = -1, MaxCSFI = -1; - - // See the description at MipsMachineFunction.h - int TopCPUSavedRegOff = -1, TopFPUSavedRegOff = -1; - - // Replace the dummy '0' SPOffset by the negative offsets, as explained on - // LowerFormalArguments. Leaving '0' for while is necessary to avoid - // the approach done by calculateFrameObjectOffsets to the stack frame. - MipsFI->adjustLoadArgsFI(MFI); - MipsFI->adjustStoreVarArgsFI(MFI); - - // It happens that the default stack frame allocation order does not directly - // map to the convention used for mips. So we must fix it. We move the callee - // save register slots after the local variables area, as described in the - // stack frame above. - unsigned CalleeSavedAreaSize = 0; - if (!CSI.empty()) { - MinCSFI = CSI[0].getFrameIdx(); - MaxCSFI = CSI[CSI.size()-1].getFrameIdx(); - } - for (unsigned i = 0, e = CSI.size(); i != e; ++i) - CalleeSavedAreaSize += MFI->getObjectAlignment(CSI[i].getFrameIdx()); - - unsigned StackOffset = HasGP ? (MipsFI->getGPStackOffset()+RegSize) - : (Subtarget.isABI_O32() ? 16 : 0); - - // Adjust local variables. They should come on the stack right - // after the arguments. - int LastOffsetFI = -1; - for (int i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) { - if (i >= MinCSFI && i <= MaxCSFI) - continue; - if (MFI->isDeadObjectIndex(i)) - continue; - unsigned Offset = - StackOffset + MFI->getObjectOffset(i) - CalleeSavedAreaSize; - if (LastOffsetFI == -1) - LastOffsetFI = i; - if (Offset > MFI->getObjectOffset(LastOffsetFI)) - LastOffsetFI = i; - MFI->setObjectOffset(i, Offset); - } - - // Adjust CPU Callee Saved Registers Area. Registers RA and FP must - // be saved in this CPU Area. This whole area must be aligned to the - // default Stack Alignment requirements. - if (LastOffsetFI >= 0) - StackOffset = MFI->getObjectOffset(LastOffsetFI)+ - MFI->getObjectSize(LastOffsetFI); - StackOffset = ((StackOffset+StackAlign-1)/StackAlign*StackAlign); - - for (unsigned i = 0, e = CSI.size(); i != e ; ++i) { - unsigned Reg = CSI[i].getReg(); - if (!Mips::CPURegsRegisterClass->contains(Reg)) - break; - MFI->setObjectOffset(CSI[i].getFrameIdx(), StackOffset); - TopCPUSavedRegOff = StackOffset; - StackOffset += MFI->getObjectAlignment(CSI[i].getFrameIdx()); - } - - // Stack locations for FP and RA. If only one of them is used, - // the space must be allocated for both, otherwise no space at all. - if (hasFP(MF) || MFI->adjustsStack()) { - // FP stack location - MFI->setObjectOffset(MFI->CreateStackObject(RegSize, RegSize, true), - StackOffset); - MipsFI->setFPStackOffset(StackOffset); - TopCPUSavedRegOff = StackOffset; - StackOffset += RegSize; - - // SP stack location - MFI->setObjectOffset(MFI->CreateStackObject(RegSize, RegSize, true), - StackOffset); - MipsFI->setRAStackOffset(StackOffset); - StackOffset += RegSize; - - if (MFI->adjustsStack()) - TopCPUSavedRegOff += RegSize; - } - - StackOffset = ((StackOffset+StackAlign-1)/StackAlign*StackAlign); - - // Adjust FPU Callee Saved Registers Area. This Area must be - // aligned to the default Stack Alignment requirements. - for (unsigned i = 0, e = CSI.size(); i != e; ++i) { - unsigned Reg = CSI[i].getReg(); - if (Mips::CPURegsRegisterClass->contains(Reg)) - continue; - MFI->setObjectOffset(CSI[i].getFrameIdx(), StackOffset); - TopFPUSavedRegOff = StackOffset; - StackOffset += MFI->getObjectAlignment(CSI[i].getFrameIdx()); - } - StackOffset = ((StackOffset+StackAlign-1)/StackAlign*StackAlign); - - // Update frame info - MFI->setStackSize(StackOffset); - - // Recalculate the final tops offset. The final values must be '0' - // if there isn't a callee saved register for CPU or FPU, otherwise - // a negative offset is needed. - if (TopCPUSavedRegOff >= 0) - MipsFI->setCPUTopSavedRegOff(TopCPUSavedRegOff-StackOffset); - - if (TopFPUSavedRegOff >= 0) - MipsFI->setFPUTopSavedRegOff(TopFPUSavedRegOff-StackOffset); -} - -// 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 MipsRegisterInfo:: -hasFP(const MachineFunction &MF) const { - const MachineFrameInfo *MFI = MF.getFrameInfo(); - return DisableFramePointerElim(MF) || MFI->hasVarSizedObjects(); -} - // This function eliminate ADJCALLSTACKDOWN, // ADJCALLSTACKUP pseudo instructions void MipsRegisterInfo:: @@ -363,106 +184,6 @@ eliminateFrameIndex(MachineBasicBlock::iterator II, int SPAdj, } void MipsRegisterInfo:: -emitPrologue(MachineFunction &MF) const -{ - MachineBasicBlock &MBB = MF.front(); - MachineFrameInfo *MFI = MF.getFrameInfo(); - MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>(); - MachineBasicBlock::iterator MBBI = MBB.begin(); - DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc(); - bool isPIC = (MF.getTarget().getRelocationModel() == Reloc::PIC_); - - // Get the right frame order for Mips. - adjustMipsStackFrame(MF); - - // Get the number of bytes to allocate from the FrameInfo. - unsigned StackSize = MFI->getStackSize(); - - // No need to allocate space on the stack. - if (StackSize == 0 && !MFI->adjustsStack()) return; - - int FPOffset = MipsFI->getFPStackOffset(); - int RAOffset = MipsFI->getRAStackOffset(); - - BuildMI(MBB, MBBI, dl, TII.get(Mips::NOREORDER)); - - // TODO: check need from GP here. - if (isPIC && Subtarget.isABI_O32()) - BuildMI(MBB, MBBI, dl, TII.get(Mips::CPLOAD)).addReg(getPICCallReg()); - BuildMI(MBB, MBBI, dl, TII.get(Mips::NOMACRO)); - - // Adjust stack : addi sp, sp, (-imm) - BuildMI(MBB, MBBI, dl, TII.get(Mips::ADDiu), Mips::SP) - .addReg(Mips::SP).addImm(-StackSize); - - // Save the return address only if the function isnt a leaf one. - // sw $ra, stack_loc($sp) - if (MFI->adjustsStack()) { - BuildMI(MBB, MBBI, dl, TII.get(Mips::SW)) - .addReg(Mips::RA).addImm(RAOffset).addReg(Mips::SP); - } - - // if framepointer enabled, save it and set it - // to point to the stack pointer - if (hasFP(MF)) { - // sw $fp,stack_loc($sp) - BuildMI(MBB, MBBI, dl, TII.get(Mips::SW)) - .addReg(Mips::FP).addImm(FPOffset).addReg(Mips::SP); - - // move $fp, $sp - BuildMI(MBB, MBBI, dl, TII.get(Mips::ADDu), Mips::FP) - .addReg(Mips::SP).addReg(Mips::ZERO); - } - - // Restore GP from the saved stack location - if (MipsFI->needGPSaveRestore()) - BuildMI(MBB, MBBI, dl, TII.get(Mips::CPRESTORE)) - .addImm(MipsFI->getGPStackOffset()); -} - -void MipsRegisterInfo:: -emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const -{ - MachineBasicBlock::iterator MBBI = prior(MBB.end()); - MachineFrameInfo *MFI = MF.getFrameInfo(); - MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>(); - DebugLoc dl = MBBI->getDebugLoc(); - - // Get the number of bytes from FrameInfo - int NumBytes = (int) MFI->getStackSize(); - - // Get the FI's where RA and FP are saved. - int FPOffset = MipsFI->getFPStackOffset(); - int RAOffset = MipsFI->getRAStackOffset(); - - // if framepointer enabled, restore it and restore the - // stack pointer - if (hasFP(MF)) { - // move $sp, $fp - BuildMI(MBB, MBBI, dl, TII.get(Mips::ADDu), Mips::SP) - .addReg(Mips::FP).addReg(Mips::ZERO); - - // lw $fp,stack_loc($sp) - BuildMI(MBB, MBBI, dl, TII.get(Mips::LW), Mips::FP) - .addImm(FPOffset).addReg(Mips::SP); - } - - // Restore the return address only if the function isnt a leaf one. - // lw $ra, stack_loc($sp) - if (MFI->adjustsStack()) { - BuildMI(MBB, MBBI, dl, TII.get(Mips::LW), Mips::RA) - .addImm(RAOffset).addReg(Mips::SP); - } - - // adjust stack : insert addi sp, sp, (imm) - if (NumBytes) { - BuildMI(MBB, MBBI, dl, TII.get(Mips::ADDiu), Mips::SP) - .addReg(Mips::SP).addImm(NumBytes); - } -} - - -void MipsRegisterInfo:: processFunctionBeforeFrameFinalized(MachineFunction &MF) const { // Set the stack offset where GP must be saved/loaded from. MachineFrameInfo *MFI = MF.getFrameInfo(); @@ -478,7 +199,9 @@ getRARegister() const { unsigned MipsRegisterInfo:: getFrameRegister(const MachineFunction &MF) const { - return hasFP(MF) ? Mips::FP : Mips::SP; + const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering(); + + return TFI->hasFP(MF) ? Mips::FP : Mips::SP; } unsigned MipsRegisterInfo:: |
