Rename TargetFrameInfo into TargetFrameLowering. Also, put couple of FIXMEs and fixes here and there.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123170 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/SystemZ/SystemZFrameLowering.cpp b/lib/Target/SystemZ/SystemZFrameLowering.cpp
new file mode 100644
index 0000000..05c2b89
--- /dev/null
+++ b/lib/Target/SystemZ/SystemZFrameLowering.cpp
@@ -0,0 +1,386 @@
+//=====- SystemZFrameLowering.cpp - SystemZ Frame Information ------*- C++ -*-====//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the SystemZ implementation of TargetFrameLowering class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SystemZFrameLowering.h"
+#include "SystemZInstrBuilder.h"
+#include "SystemZInstrInfo.h"
+#include "SystemZMachineFunctionInfo.h"
+#include "llvm/Function.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/Support/CommandLine.h"
+
+using namespace llvm;
+
+SystemZFrameLowering::SystemZFrameLowering(const SystemZSubtarget &sti)
+ : TargetFrameLowering(TargetFrameLowering::StackGrowsDown, 8, -160), STI(sti) {
+ // Fill the spill offsets map
+ static const unsigned SpillOffsTab[][2] = {
+ { SystemZ::R2D, 0x10 },
+ { SystemZ::R3D, 0x18 },
+ { SystemZ::R4D, 0x20 },
+ { SystemZ::R5D, 0x28 },
+ { SystemZ::R6D, 0x30 },
+ { SystemZ::R7D, 0x38 },
+ { SystemZ::R8D, 0x40 },
+ { SystemZ::R9D, 0x48 },
+ { SystemZ::R10D, 0x50 },
+ { SystemZ::R11D, 0x58 },
+ { SystemZ::R12D, 0x60 },
+ { SystemZ::R13D, 0x68 },
+ { SystemZ::R14D, 0x70 },
+ { SystemZ::R15D, 0x78 }
+ };
+
+ RegSpillOffsets.grow(SystemZ::NUM_TARGET_REGS);
+
+ for (unsigned i = 0, e = array_lengthof(SpillOffsTab); i != e; ++i)
+ RegSpillOffsets[SpillOffsTab[i][0]] = SpillOffsTab[i][1];
+}
+
+/// needsFP - 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 SystemZFrameLowering::hasFP(const MachineFunction &MF) const {
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+ return DisableFramePointerElim(MF) || MFI->hasVarSizedObjects();
+}
+
+/// emitSPUpdate - Emit a series of instructions to increment / decrement the
+/// stack pointer by a constant value.
+static
+void emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
+ int64_t NumBytes, const TargetInstrInfo &TII) {
+ unsigned Opc; uint64_t Chunk;
+ bool isSub = NumBytes < 0;
+ uint64_t Offset = isSub ? -NumBytes : NumBytes;
+
+ if (Offset >= (1LL << 15) - 1) {
+ Opc = SystemZ::ADD64ri32;
+ Chunk = (1LL << 31) - 1;
+ } else {
+ Opc = SystemZ::ADD64ri16;
+ Chunk = (1LL << 15) - 1;
+ }
+
+ DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
+
+ while (Offset) {
+ uint64_t ThisVal = (Offset > Chunk) ? Chunk : Offset;
+ MachineInstr *MI =
+ BuildMI(MBB, MBBI, DL, TII.get(Opc), SystemZ::R15D)
+ .addReg(SystemZ::R15D).addImm(isSub ? -ThisVal : ThisVal);
+ // The PSW implicit def is dead.
+ MI->getOperand(3).setIsDead();
+ Offset -= ThisVal;
+ }
+}
+
+void SystemZFrameLowering::emitPrologue(MachineFunction &MF) const {
+ MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ const SystemZInstrInfo &TII =
+ *static_cast<const SystemZInstrInfo*>(MF.getTarget().getInstrInfo());
+ SystemZMachineFunctionInfo *SystemZMFI =
+ MF.getInfo<SystemZMachineFunctionInfo>();
+ MachineBasicBlock::iterator MBBI = MBB.begin();
+ DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
+
+ // Get the number of bytes to allocate from the FrameInfo.
+ // Note that area for callee-saved stuff is already allocated, thus we need to
+ // 'undo' the stack movement.
+ uint64_t StackSize = MFI->getStackSize();
+ StackSize -= SystemZMFI->getCalleeSavedFrameSize();
+
+ uint64_t NumBytes = StackSize - getOffsetOfLocalArea();
+
+ // Skip the callee-saved push instructions.
+ while (MBBI != MBB.end() &&
+ (MBBI->getOpcode() == SystemZ::MOV64mr ||
+ MBBI->getOpcode() == SystemZ::MOV64mrm))
+ ++MBBI;
+
+ if (MBBI != MBB.end())
+ DL = MBBI->getDebugLoc();
+
+ // adjust stack pointer: R15 -= numbytes
+ if (StackSize || MFI->hasCalls()) {
+ assert(MF.getRegInfo().isPhysRegUsed(SystemZ::R15D) &&
+ "Invalid stack frame calculation!");
+ emitSPUpdate(MBB, MBBI, -(int64_t)NumBytes, TII);
+ }
+
+ if (hasFP(MF)) {
+ // Update R11 with the new base value...
+ BuildMI(MBB, MBBI, DL, TII.get(SystemZ::MOV64rr), SystemZ::R11D)
+ .addReg(SystemZ::R15D);
+
+ // Mark the FramePtr as live-in in every block except the entry.
+ for (MachineFunction::iterator I = llvm::next(MF.begin()), E = MF.end();
+ I != E; ++I)
+ I->addLiveIn(SystemZ::R11D);
+
+ }
+}
+
+void SystemZFrameLowering::emitEpilogue(MachineFunction &MF,
+ MachineBasicBlock &MBB) const {
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+ MachineBasicBlock::iterator MBBI = prior(MBB.end());
+ const SystemZInstrInfo &TII =
+ *static_cast<const SystemZInstrInfo*>(MF.getTarget().getInstrInfo());
+ SystemZMachineFunctionInfo *SystemZMFI =
+ MF.getInfo<SystemZMachineFunctionInfo>();
+ unsigned RetOpcode = MBBI->getOpcode();
+
+ switch (RetOpcode) {
+ case SystemZ::RET: break; // These are ok
+ default:
+ assert(0 && "Can only insert epilog into returning blocks");
+ }
+
+ // Get the number of bytes to allocate from the FrameInfo
+ // Note that area for callee-saved stuff is already allocated, thus we need to
+ // 'undo' the stack movement.
+ uint64_t StackSize =
+ MFI->getStackSize() - SystemZMFI->getCalleeSavedFrameSize();
+ uint64_t NumBytes = StackSize - getOffsetOfLocalArea();
+
+ // Skip the final terminator instruction.
+ while (MBBI != MBB.begin()) {
+ MachineBasicBlock::iterator PI = prior(MBBI);
+ --MBBI;
+ if (!PI->getDesc().isTerminator())
+ break;
+ }
+
+ // During callee-saved restores emission stack frame was not yet finialized
+ // (and thus - the stack size was unknown). Tune the offset having full stack
+ // size in hands.
+ if (StackSize || MFI->hasCalls()) {
+ assert((MBBI->getOpcode() == SystemZ::MOV64rmm ||
+ MBBI->getOpcode() == SystemZ::MOV64rm) &&
+ "Expected to see callee-save register restore code");
+ assert(MF.getRegInfo().isPhysRegUsed(SystemZ::R15D) &&
+ "Invalid stack frame calculation!");
+
+ unsigned i = 0;
+ MachineInstr &MI = *MBBI;
+ while (!MI.getOperand(i).isImm()) {
+ ++i;
+ assert(i < MI.getNumOperands() && "Unexpected restore code!");
+ }
+
+ uint64_t Offset = NumBytes + MI.getOperand(i).getImm();
+ // If Offset does not fit into 20-bit signed displacement field we need to
+ // emit some additional code...
+ if (Offset > 524287) {
+ // Fold the displacement into load instruction as much as possible.
+ NumBytes = Offset - 524287;
+ Offset = 524287;
+ emitSPUpdate(MBB, MBBI, NumBytes, TII);
+ }
+
+ MI.getOperand(i).ChangeToImmediate(Offset);
+ }
+}
+
+int SystemZFrameLowering::getFrameIndexOffset(const MachineFunction &MF,
+ int FI) const {
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+ const SystemZMachineFunctionInfo *SystemZMFI =
+ MF.getInfo<SystemZMachineFunctionInfo>();
+ int Offset = MFI->getObjectOffset(FI) + MFI->getOffsetAdjustment();
+ uint64_t StackSize = MFI->getStackSize();
+
+ // Fixed objects are really located in the "previous" frame.
+ if (FI < 0)
+ StackSize -= SystemZMFI->getCalleeSavedFrameSize();
+
+ Offset += StackSize - getOffsetOfLocalArea();
+
+ // Skip the register save area if we generated the stack frame.
+ if (StackSize || MFI->hasCalls())
+ Offset -= getOffsetOfLocalArea();
+
+ return Offset;
+}
+
+bool
+SystemZFrameLowering::spillCalleeSavedRegisters(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MI,
+ const std::vector<CalleeSavedInfo> &CSI,
+ const TargetRegisterInfo *TRI) const {
+ if (CSI.empty())
+ return false;
+
+ DebugLoc DL;
+ if (MI != MBB.end()) DL = MI->getDebugLoc();
+
+ MachineFunction &MF = *MBB.getParent();
+ const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
+ SystemZMachineFunctionInfo *MFI = MF.getInfo<SystemZMachineFunctionInfo>();
+ unsigned CalleeFrameSize = 0;
+
+ // Scan the callee-saved and find the bounds of register spill area.
+ unsigned LowReg = 0, HighReg = 0, StartOffset = -1U, EndOffset = 0;
+ for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
+ unsigned Reg = CSI[i].getReg();
+ if (!SystemZ::FP64RegClass.contains(Reg)) {
+ unsigned Offset = RegSpillOffsets[Reg];
+ CalleeFrameSize += 8;
+ if (StartOffset > Offset) {
+ LowReg = Reg; StartOffset = Offset;
+ }
+ if (EndOffset < Offset) {
+ HighReg = Reg; EndOffset = RegSpillOffsets[Reg];
+ }
+ }
+ }
+
+ // Save information for epilogue inserter.
+ MFI->setCalleeSavedFrameSize(CalleeFrameSize);
+ MFI->setLowReg(LowReg); MFI->setHighReg(HighReg);
+
+ // Save GPRs
+ if (StartOffset) {
+ // Build a store instruction. Use STORE MULTIPLE instruction if there are many
+ // registers to store, otherwise - just STORE.
+ MachineInstrBuilder MIB =
+ BuildMI(MBB, MI, DL, TII.get((LowReg == HighReg ?
+ SystemZ::MOV64mr : SystemZ::MOV64mrm)));
+
+ // Add store operands.
+ MIB.addReg(SystemZ::R15D).addImm(StartOffset);
+ if (LowReg == HighReg)
+ MIB.addReg(0);
+ MIB.addReg(LowReg, RegState::Kill);
+ if (LowReg != HighReg)
+ MIB.addReg(HighReg, RegState::Kill);
+
+ // Do a second scan adding regs as being killed by instruction
+ for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
+ unsigned Reg = CSI[i].getReg();
+ // Add the callee-saved register as live-in. It's killed at the spill.
+ MBB.addLiveIn(Reg);
+ if (Reg != LowReg && Reg != HighReg)
+ MIB.addReg(Reg, RegState::ImplicitKill);
+ }
+ }
+
+ // Save FPRs
+ for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
+ unsigned Reg = CSI[i].getReg();
+ if (SystemZ::FP64RegClass.contains(Reg)) {
+ MBB.addLiveIn(Reg);
+ TII.storeRegToStackSlot(MBB, MI, Reg, true, CSI[i].getFrameIdx(),
+ &SystemZ::FP64RegClass, TRI);
+ }
+ }
+
+ return true;
+}
+
+bool
+SystemZFrameLowering::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MI,
+ const std::vector<CalleeSavedInfo> &CSI,
+ const TargetRegisterInfo *TRI) const {
+ if (CSI.empty())
+ return false;
+
+ DebugLoc DL;
+ if (MI != MBB.end()) DL = MI->getDebugLoc();
+
+ MachineFunction &MF = *MBB.getParent();
+ const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
+ SystemZMachineFunctionInfo *MFI = MF.getInfo<SystemZMachineFunctionInfo>();
+
+ // Restore FP registers
+ for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
+ unsigned Reg = CSI[i].getReg();
+ if (SystemZ::FP64RegClass.contains(Reg))
+ TII.loadRegFromStackSlot(MBB, MI, Reg, CSI[i].getFrameIdx(),
+ &SystemZ::FP64RegClass, TRI);
+ }
+
+ // Restore GP registers
+ unsigned LowReg = MFI->getLowReg(), HighReg = MFI->getHighReg();
+ unsigned StartOffset = RegSpillOffsets[LowReg];
+
+ if (StartOffset) {
+ // Build a load instruction. Use LOAD MULTIPLE instruction if there are many
+ // registers to load, otherwise - just LOAD.
+ MachineInstrBuilder MIB =
+ BuildMI(MBB, MI, DL, TII.get((LowReg == HighReg ?
+ SystemZ::MOV64rm : SystemZ::MOV64rmm)));
+ // Add store operands.
+ MIB.addReg(LowReg, RegState::Define);
+ if (LowReg != HighReg)
+ MIB.addReg(HighReg, RegState::Define);
+
+ MIB.addReg(hasFP(MF) ? SystemZ::R11D : SystemZ::R15D);
+ MIB.addImm(StartOffset);
+ if (LowReg == HighReg)
+ MIB.addReg(0);
+
+ // Do a second scan adding regs as being defined by instruction
+ for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
+ unsigned Reg = CSI[i].getReg();
+ if (Reg != LowReg && Reg != HighReg)
+ MIB.addReg(Reg, RegState::ImplicitDefine);
+ }
+ }
+
+ return true;
+}
+
+void
+SystemZFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
+ RegScavenger *RS) const {
+ // Determine whether R15/R14 will ever be clobbered inside the function. And
+ // if yes - mark it as 'callee' saved.
+ MachineFrameInfo *FFI = MF.getFrameInfo();
+ MachineRegisterInfo &MRI = MF.getRegInfo();
+
+ // Check whether high FPRs are ever used, if yes - we need to save R15 as
+ // well.
+ static const unsigned HighFPRs[] = {
+ SystemZ::F8L, SystemZ::F9L, SystemZ::F10L, SystemZ::F11L,
+ SystemZ::F12L, SystemZ::F13L, SystemZ::F14L, SystemZ::F15L,
+ SystemZ::F8S, SystemZ::F9S, SystemZ::F10S, SystemZ::F11S,
+ SystemZ::F12S, SystemZ::F13S, SystemZ::F14S, SystemZ::F15S,
+ };
+
+ bool HighFPRsUsed = false;
+ for (unsigned i = 0, e = array_lengthof(HighFPRs); i != e; ++i)
+ HighFPRsUsed |= MRI.isPhysRegUsed(HighFPRs[i]);
+
+ if (FFI->hasCalls())
+ /* FIXME: function is varargs */
+ /* FIXME: function grabs RA */
+ /* FIXME: function calls eh_return */
+ MRI.setPhysRegUsed(SystemZ::R14D);
+
+ if (HighFPRsUsed ||
+ FFI->hasCalls() ||
+ FFI->getObjectIndexEnd() != 0 || // Contains automatic variables
+ FFI->hasVarSizedObjects() // Function calls dynamic alloca's
+ /* FIXME: function is varargs */)
+ MRI.setPhysRegUsed(SystemZ::R15D);
+}