| //===-- VEFrameLowering.cpp - VE Frame Information ------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file contains the VE implementation of TargetFrameLowering class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "VEFrameLowering.h" |
| #include "VEInstrInfo.h" |
| #include "VEMachineFunctionInfo.h" |
| #include "VESubtarget.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/CodeGen/RegisterScavenging.h" |
| #include "llvm/IR/DataLayout.h" |
| #include "llvm/IR/Function.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Target/TargetOptions.h" |
| #include "llvm/Support/MathExtras.h" |
| |
| using namespace llvm; |
| |
| VEFrameLowering::VEFrameLowering(const VESubtarget &ST) |
| : TargetFrameLowering(TargetFrameLowering::StackGrowsDown, Align(16), 0, |
| Align(16)), |
| STI(ST) {} |
| |
| void VEFrameLowering::emitPrologueInsns(MachineFunction &MF, |
| MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator MBBI, |
| uint64_t NumBytes, |
| bool RequireFPUpdate) const { |
| |
| DebugLoc dl; |
| const VEInstrInfo &TII = |
| *static_cast<const VEInstrInfo *>(MF.getSubtarget().getInstrInfo()); |
| // Insert following codes here as prologue |
| // |
| // st %fp, 0(,%sp) |
| // st %lr, 8(,%sp) |
| // st %got, 24(,%sp) |
| // st %plt, 32(,%sp) |
| // st %s17, 40(,%sp) iff this function is using s17 as BP |
| // or %fp, 0, %sp |
| |
| BuildMI(MBB, MBBI, dl, TII.get(VE::STrii)) |
| .addReg(VE::SX11) |
| .addImm(0) |
| .addImm(0) |
| .addReg(VE::SX9); |
| BuildMI(MBB, MBBI, dl, TII.get(VE::STrii)) |
| .addReg(VE::SX11) |
| .addImm(0) |
| .addImm(8) |
| .addReg(VE::SX10); |
| BuildMI(MBB, MBBI, dl, TII.get(VE::STrii)) |
| .addReg(VE::SX11) |
| .addImm(0) |
| .addImm(24) |
| .addReg(VE::SX15); |
| BuildMI(MBB, MBBI, dl, TII.get(VE::STrii)) |
| .addReg(VE::SX11) |
| .addImm(0) |
| .addImm(32) |
| .addReg(VE::SX16); |
| if (hasBP(MF)) |
| BuildMI(MBB, MBBI, dl, TII.get(VE::STrii)) |
| .addReg(VE::SX11) |
| .addImm(0) |
| .addImm(40) |
| .addReg(VE::SX17); |
| BuildMI(MBB, MBBI, dl, TII.get(VE::ORri), VE::SX9) |
| .addReg(VE::SX11) |
| .addImm(0); |
| } |
| |
| void VEFrameLowering::emitEpilogueInsns(MachineFunction &MF, |
| MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator MBBI, |
| uint64_t NumBytes, |
| bool RequireFPUpdate) const { |
| |
| DebugLoc dl; |
| const VEInstrInfo &TII = |
| *static_cast<const VEInstrInfo *>(MF.getSubtarget().getInstrInfo()); |
| // Insert following codes here as epilogue |
| // |
| // or %sp, 0, %fp |
| // ld %s17, 40(,%sp) iff this function is using s17 as BP |
| // ld %got, 32(,%sp) |
| // ld %plt, 24(,%sp) |
| // ld %lr, 8(,%sp) |
| // ld %fp, 0(,%sp) |
| |
| BuildMI(MBB, MBBI, dl, TII.get(VE::ORri), VE::SX11) |
| .addReg(VE::SX9) |
| .addImm(0); |
| if (hasBP(MF)) |
| BuildMI(MBB, MBBI, dl, TII.get(VE::LDrii), VE::SX17) |
| .addReg(VE::SX11) |
| .addImm(0) |
| .addImm(40); |
| BuildMI(MBB, MBBI, dl, TII.get(VE::LDrii), VE::SX16) |
| .addReg(VE::SX11) |
| .addImm(0) |
| .addImm(32); |
| BuildMI(MBB, MBBI, dl, TII.get(VE::LDrii), VE::SX15) |
| .addReg(VE::SX11) |
| .addImm(0) |
| .addImm(24); |
| BuildMI(MBB, MBBI, dl, TII.get(VE::LDrii), VE::SX10) |
| .addReg(VE::SX11) |
| .addImm(0) |
| .addImm(8); |
| BuildMI(MBB, MBBI, dl, TII.get(VE::LDrii), VE::SX9) |
| .addReg(VE::SX11) |
| .addImm(0) |
| .addImm(0); |
| } |
| |
| void VEFrameLowering::emitSPAdjustment(MachineFunction &MF, |
| MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator MBBI, |
| int64_t NumBytes, |
| MaybeAlign MaybeAlign) const { |
| DebugLoc dl; |
| const VEInstrInfo &TII = |
| *static_cast<const VEInstrInfo *>(MF.getSubtarget().getInstrInfo()); |
| |
| if (NumBytes >= -64 && NumBytes < 63) { |
| BuildMI(MBB, MBBI, dl, TII.get(VE::ADDSLri), VE::SX11) |
| .addReg(VE::SX11) |
| .addImm(NumBytes); |
| return; |
| } |
| |
| // Emit following codes. This clobbers SX13 which we always know is |
| // available here. |
| // lea %s13,%lo(NumBytes) |
| // and %s13,%s13,(32)0 |
| // lea.sl %sp,%hi(NumBytes)(%sp, %s13) |
| BuildMI(MBB, MBBI, dl, TII.get(VE::LEAzii), VE::SX13) |
| .addImm(0) |
| .addImm(0) |
| .addImm(Lo_32(NumBytes)); |
| BuildMI(MBB, MBBI, dl, TII.get(VE::ANDrm), VE::SX13) |
| .addReg(VE::SX13) |
| .addImm(M0(32)); |
| BuildMI(MBB, MBBI, dl, TII.get(VE::LEASLrri), VE::SX11) |
| .addReg(VE::SX11) |
| .addReg(VE::SX13) |
| .addImm(Hi_32(NumBytes)); |
| |
| if (MaybeAlign) { |
| // and %sp, %sp, Align-1 |
| BuildMI(MBB, MBBI, dl, TII.get(VE::ANDrm), VE::SX11) |
| .addReg(VE::SX11) |
| .addImm(M1(64 - Log2_64(MaybeAlign.valueOrOne().value()))); |
| } |
| } |
| |
| void VEFrameLowering::emitSPExtend(MachineFunction &MF, MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator MBBI) const { |
| DebugLoc dl; |
| const VEInstrInfo &TII = |
| *static_cast<const VEInstrInfo *>(MF.getSubtarget().getInstrInfo()); |
| |
| // Emit following codes. It is not possible to insert multiple |
| // BasicBlocks in PEI pass, so we emit two pseudo instructions here. |
| // |
| // EXTEND_STACK // pseudo instrcution |
| // EXTEND_STACK_GUARD // pseudo instrcution |
| // |
| // EXTEND_STACK pseudo will be converted by ExpandPostRA pass into |
| // following instructions with multiple basic blocks later. |
| // |
| // thisBB: |
| // brge.l.t %sp, %sl, sinkBB |
| // syscallBB: |
| // ld %s61, 0x18(, %tp) // load param area |
| // or %s62, 0, %s0 // spill the value of %s0 |
| // lea %s63, 0x13b // syscall # of grow |
| // shm.l %s63, 0x0(%s61) // store syscall # at addr:0 |
| // shm.l %sl, 0x8(%s61) // store old limit at addr:8 |
| // shm.l %sp, 0x10(%s61) // store new limit at addr:16 |
| // monc // call monitor |
| // or %s0, 0, %s62 // restore the value of %s0 |
| // sinkBB: |
| // |
| // EXTEND_STACK_GUARD pseudo will be simply eliminated by ExpandPostRA |
| // pass. This pseudo is required to be at the next of EXTEND_STACK |
| // pseudo in order to protect iteration loop in ExpandPostRA. |
| |
| BuildMI(MBB, MBBI, dl, TII.get(VE::EXTEND_STACK)); |
| BuildMI(MBB, MBBI, dl, TII.get(VE::EXTEND_STACK_GUARD)); |
| } |
| |
| void VEFrameLowering::emitPrologue(MachineFunction &MF, |
| MachineBasicBlock &MBB) const { |
| assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported"); |
| MachineFrameInfo &MFI = MF.getFrameInfo(); |
| const VEInstrInfo &TII = *STI.getInstrInfo(); |
| const VERegisterInfo &RegInfo = *STI.getRegisterInfo(); |
| MachineBasicBlock::iterator MBBI = MBB.begin(); |
| // Debug location must be unknown since the first debug location is used |
| // to determine the end of the prologue. |
| DebugLoc dl; |
| bool NeedsStackRealignment = RegInfo.needsStackRealignment(MF); |
| |
| // FIXME: unfortunately, returning false from canRealignStack |
| // actually just causes needsStackRealignment to return false, |
| // rather than reporting an error, as would be sensible. This is |
| // poor, but fixing that bogosity is going to be a large project. |
| // For now, just see if it's lied, and report an error here. |
| if (!NeedsStackRealignment && MFI.getMaxAlign() > getStackAlign()) |
| report_fatal_error("Function \"" + Twine(MF.getName()) + |
| "\" required " |
| "stack re-alignment, but LLVM couldn't handle it " |
| "(probably because it has a dynamic alloca)."); |
| |
| // Get the number of bytes to allocate from the FrameInfo |
| uint64_t NumBytes = MFI.getStackSize(); |
| |
| // The VE ABI requires a reserved 176 bytes area at the top |
| // of stack as described in VESubtarget.cpp. So, we adjust it here. |
| NumBytes = STI.getAdjustedFrameSize(NumBytes); |
| |
| // Finally, ensure that the size is sufficiently aligned for the |
| // data on the stack. |
| NumBytes = alignTo(NumBytes, MFI.getMaxAlign()); |
| |
| // Update stack size with corrected value. |
| MFI.setStackSize(NumBytes); |
| |
| // Emit Prologue instructions to save %lr |
| emitPrologueInsns(MF, MBB, MBBI, NumBytes, true); |
| |
| // Emit stack adjust instructions |
| MaybeAlign RuntimeAlign = |
| NeedsStackRealignment ? MaybeAlign(MFI.getMaxAlign()) : None; |
| emitSPAdjustment(MF, MBB, MBBI, -(int64_t)NumBytes, RuntimeAlign); |
| |
| if (hasBP(MF)) { |
| // Copy SP to BP. |
| BuildMI(MBB, MBBI, dl, TII.get(VE::ORri), VE::SX17) |
| .addReg(VE::SX11) |
| .addImm(0); |
| } |
| |
| // Emit stack extend instructions |
| emitSPExtend(MF, MBB, MBBI); |
| |
| Register RegFP = RegInfo.getDwarfRegNum(VE::SX9, true); |
| |
| // Emit ".cfi_def_cfa_register 30". |
| unsigned CFIIndex = |
| MF.addFrameInst(MCCFIInstruction::createDefCfaRegister(nullptr, RegFP)); |
| BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION)) |
| .addCFIIndex(CFIIndex); |
| |
| // Emit ".cfi_window_save". |
| CFIIndex = MF.addFrameInst(MCCFIInstruction::createWindowSave(nullptr)); |
| BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION)) |
| .addCFIIndex(CFIIndex); |
| } |
| |
| MachineBasicBlock::iterator VEFrameLowering::eliminateCallFramePseudoInstr( |
| MachineFunction &MF, MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator I) const { |
| if (!hasReservedCallFrame(MF)) { |
| MachineInstr &MI = *I; |
| int64_t Size = MI.getOperand(0).getImm(); |
| if (MI.getOpcode() == VE::ADJCALLSTACKDOWN) |
| Size = -Size; |
| |
| if (Size) |
| emitSPAdjustment(MF, MBB, I, Size); |
| } |
| return MBB.erase(I); |
| } |
| |
| void VEFrameLowering::emitEpilogue(MachineFunction &MF, |
| MachineBasicBlock &MBB) const { |
| MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr(); |
| DebugLoc dl = MBBI->getDebugLoc(); |
| MachineFrameInfo &MFI = MF.getFrameInfo(); |
| |
| uint64_t NumBytes = MFI.getStackSize(); |
| |
| // Emit Epilogue instructions to restore %lr |
| emitEpilogueInsns(MF, MBB, MBBI, NumBytes, true); |
| } |
| |
| // 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. For the case of VE, we don't |
| // implement FP eliminator yet, but we returns false from this function to |
| // not refer fp from generated code. |
| bool VEFrameLowering::hasFP(const MachineFunction &MF) const { |
| const TargetRegisterInfo *RegInfo = MF.getSubtarget().getRegisterInfo(); |
| |
| const MachineFrameInfo &MFI = MF.getFrameInfo(); |
| return MF.getTarget().Options.DisableFramePointerElim(MF) || |
| RegInfo->needsStackRealignment(MF) || MFI.hasVarSizedObjects() || |
| MFI.isFrameAddressTaken(); |
| } |
| |
| bool VEFrameLowering::hasBP(const MachineFunction &MF) const { |
| const MachineFrameInfo &MFI = MF.getFrameInfo(); |
| const TargetRegisterInfo *TRI = STI.getRegisterInfo(); |
| |
| return MFI.hasVarSizedObjects() && TRI->needsStackRealignment(MF); |
| } |
| |
| int VEFrameLowering::getFrameIndexReference(const MachineFunction &MF, int FI, |
| Register &FrameReg) const { |
| const MachineFrameInfo &MFI = MF.getFrameInfo(); |
| const VERegisterInfo *RegInfo = STI.getRegisterInfo(); |
| const VEMachineFunctionInfo *FuncInfo = MF.getInfo<VEMachineFunctionInfo>(); |
| bool isFixed = MFI.isFixedObjectIndex(FI); |
| |
| int64_t FrameOffset = MF.getFrameInfo().getObjectOffset(FI); |
| |
| if (FuncInfo->isLeafProc()) { |
| // If there's a leaf proc, all offsets need to be %sp-based, |
| // because we haven't caused %fp to actually point to our frame. |
| FrameReg = VE::SX11; // %sp |
| return FrameOffset + MF.getFrameInfo().getStackSize(); |
| } |
| if (RegInfo->needsStackRealignment(MF) && !isFixed) { |
| // If there is dynamic stack realignment, all local object |
| // references need to be via %sp or %s17 (bp), to take account |
| // of the re-alignment. |
| if (hasBP(MF)) |
| FrameReg = VE::SX17; // %bp |
| else |
| FrameReg = VE::SX11; // %sp |
| return FrameOffset + MF.getFrameInfo().getStackSize(); |
| } |
| // Finally, default to using %fp. |
| FrameReg = RegInfo->getFrameRegister(MF); |
| return FrameOffset; |
| } |
| |
| bool VEFrameLowering::isLeafProc(MachineFunction &MF) const { |
| |
| MachineRegisterInfo &MRI = MF.getRegInfo(); |
| MachineFrameInfo &MFI = MF.getFrameInfo(); |
| |
| return !MFI.hasCalls() // No calls |
| && !MRI.isPhysRegUsed(VE::SX18) // Registers within limits |
| // (s18 is first CSR) |
| && !MRI.isPhysRegUsed(VE::SX11) // %sp un-used |
| && !hasFP(MF); // Don't need %fp |
| } |
| |
| void VEFrameLowering::determineCalleeSaves(MachineFunction &MF, |
| BitVector &SavedRegs, |
| RegScavenger *RS) const { |
| TargetFrameLowering::determineCalleeSaves(MF, SavedRegs, RS); |
| |
| if (isLeafProc(MF)) { |
| VEMachineFunctionInfo *MFI = MF.getInfo<VEMachineFunctionInfo>(); |
| MFI->setLeafProc(true); |
| } |
| } |