-//=======- MipsFrameLowering.cpp - Mips Frame Information ------*- C++ -*-====//
+//===-- MipsFrameLowering.cpp - Mips Frame Information --------------------===//
//
// The LLVM Compiler Infrastructure
//
//===----------------------------------------------------------------------===//
#include "MipsFrameLowering.h"
+#include "MCTargetDesc/MipsBaseInfo.h"
+#include "MipsAnalyzeImmediate.h"
#include "MipsInstrInfo.h"
#include "MipsMachineFunction.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/DataLayout.h"
+#include "llvm/Function.h"
#include "llvm/Support/CommandLine.h"
+#include "llvm/Target/TargetOptions.h"
using namespace llvm;
//
//===----------------------------------------------------------------------===//
+const MipsFrameLowering *MipsFrameLowering::create(MipsTargetMachine &TM,
+ const MipsSubtarget &ST) {
+ if (TM.getSubtargetImpl()->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.
bool MipsFrameLowering::hasFP(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
- return DisableFramePointerElim(MF) || MFI->hasVarSizedObjects();
-}
-
-void MipsFrameLowering::adjustMipsStackFrame(MachineFunction &MF) const {
- MachineFrameInfo *MFI = MF.getFrameInfo();
- MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
- const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
- unsigned StackAlign = getStackAlignment();
- unsigned RegSize = STI.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)
- : (STI.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);
+ return MF.getTarget().Options.DisableFramePointerElim(MF) ||
+ MFI->hasVarSizedObjects() || MFI->isFrameAddressTaken();
}
-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();
- 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 && STI.isABI_O32())
- BuildMI(MBB, MBBI, dl, TII.get(Mips::CPLOAD))
- .addReg(RegInfo->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);
+uint64_t MipsFrameLowering::estimateStackSize(const MachineFunction &MF) const {
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+ const TargetRegisterInfo &TRI = *MF.getTarget().getRegisterInfo();
- // 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);
- }
+ int64_t Offset = 0;
- // 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);
+ // Iterate over fixed sized objects.
+ for (int I = MFI->getObjectIndexBegin(); I != 0; ++I)
+ Offset = std::max(Offset, -MFI->getObjectOffset(I));
- // move $fp, $sp
- BuildMI(MBB, MBBI, dl, TII.get(Mips::ADDu), Mips::FP)
- .addReg(Mips::SP).addReg(Mips::ZERO);
+ // Conservatively assume all callee-saved registers will be saved.
+ for (const uint16_t *R = TRI.getCalleeSavedRegs(&MF); *R; ++R) {
+ unsigned Size = TRI.getMinimalPhysRegClass(*R)->getSize();
+ Offset = RoundUpToAlignment(Offset + Size, Size);
}
- // Restore GP from the saved stack location
- if (MipsFI->needGPSaveRestore())
- BuildMI(MBB, MBBI, dl, TII.get(Mips::CPRESTORE))
- .addImm(MipsFI->getGPStackOffset());
-}
-
-void MipsFrameLowering::emitEpilogue(MachineFunction &MF,
- MachineBasicBlock &MBB) const {
- MachineBasicBlock::iterator MBBI = prior(MBB.end());
- MachineFrameInfo *MFI = MF.getFrameInfo();
- MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
- const MipsInstrInfo &TII =
- *static_cast<const MipsInstrInfo*>(MF.getTarget().getInstrInfo());
- DebugLoc dl = MBBI->getDebugLoc();
+ unsigned MaxAlign = MFI->getMaxAlignment();
- // Get the number of bytes from FrameInfo
- int NumBytes = (int) MFI->getStackSize();
+ // Check that MaxAlign is not zero if there is a stack object that is not a
+ // callee-saved spill.
+ assert(!MFI->getObjectIndexEnd() || MaxAlign);
- // Get the FI's where RA and FP are saved.
- int FPOffset = MipsFI->getFPStackOffset();
- int RAOffset = MipsFI->getRAStackOffset();
+ // Iterate over other objects.
+ for (unsigned I = 0, E = MFI->getObjectIndexEnd(); I != E; ++I)
+ Offset = RoundUpToAlignment(Offset + MFI->getObjectSize(I), MaxAlign);
- // 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);
+ // Call frame.
+ if (MFI->adjustsStack() && hasReservedCallFrame(MF))
+ Offset = RoundUpToAlignment(Offset + MFI->getMaxCallFrameSize(),
+ std::max(MaxAlign, getStackAlignment()));
- // 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);
- }
+ return RoundUpToAlignment(Offset, getStackAlignment());
}
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