//
//===----------------------------------------------------------------------===//
+#define DEBUG_TYPE "mblaze-frame-info"
+
#include "MBlazeFrameInfo.h"
#include "MBlazeInstrInfo.h"
#include "MBlazeMachineFunction.h"
+#include "InstPrinter/MBlazeInstPrinter.h"
#include "llvm/Function.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
using namespace llvm;
+namespace llvm {
+ cl::opt<bool> DisableStackAdjust(
+ "disable-mblaze-stack-adjust",
+ cl::init(false),
+ cl::desc("Disable MBlaze stack layout adjustment."),
+ cl::Hidden);
+}
+
+static void replaceFrameIndexes(MachineFunction &MF,
+ SmallVector<std::pair<int,int64_t>, 16> &FR) {
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ const SmallVector<std::pair<int,int64_t>, 16>::iterator FRB = FR.begin();
+ const SmallVector<std::pair<int,int64_t>, 16>::iterator FRE = FR.end();
+
+ SmallVector<std::pair<int,int64_t>, 16>::iterator FRI = FRB;
+ for (; FRI != FRE; ++FRI) {
+ MFI->RemoveStackObject(FRI->first);
+ int NFI = MFI->CreateFixedObject(4, FRI->second, true);
+
+ for (MachineFunction::iterator MB=MF.begin(), ME=MF.end(); MB!=ME; ++MB) {
+ MachineBasicBlock::iterator MBB = MB->begin();
+ const MachineBasicBlock::iterator MBE = MB->end();
+
+ for (; MBB != MBE; ++MBB) {
+ MachineInstr::mop_iterator MIB = MBB->operands_begin();
+ const MachineInstr::mop_iterator MIE = MBB->operands_end();
+
+ for (MachineInstr::mop_iterator MII = MIB; MII != MIE; ++MII) {
+ if (!MII->isFI() || MII->getIndex() != FRI->first) continue;
+ DEBUG(dbgs() << "FOUND FI#" << MII->getIndex() << "\n");
+ MII->setIndex(NFI);
+ }
+ }
+ }
+ }
+}
//===----------------------------------------------------------------------===//
//
//
//===----------------------------------------------------------------------===//
-void MBlazeFrameInfo::adjustMBlazeStackFrame(MachineFunction &MF) const {
+static void analyzeFrameIndexes(MachineFunction &MF) {
+ if (DisableStackAdjust) return;
+
MachineFrameInfo *MFI = MF.getFrameInfo();
MBlazeFunctionInfo *MBlazeFI = MF.getInfo<MBlazeFunctionInfo>();
- const MBlazeRegisterInfo *RegInfo =
- static_cast<const MBlazeRegisterInfo*>(MF.getTarget().getRegisterInfo());
+ const MachineRegisterInfo &MRI = MF.getRegInfo();
+
+ MachineRegisterInfo::livein_iterator LII = MRI.livein_begin();
+ MachineRegisterInfo::livein_iterator LIE = MRI.livein_end();
+ const SmallVector<int, 16> &LiveInFI = MBlazeFI->getLiveIn();
+ SmallVector<MachineInstr*, 16> EraseInstr;
+ SmallVector<std::pair<int,int64_t>, 16> FrameRelocate;
+
+ MachineBasicBlock *MBB = MF.getBlockNumbered(0);
+ MachineBasicBlock::iterator MIB = MBB->begin();
+ MachineBasicBlock::iterator MIE = MBB->end();
+
+ int StackAdjust = 0;
+ int StackOffset = -28;
+
+ // In this loop we are searching frame indexes that corrospond to incoming
+ // arguments that are already in the stack. We look for instruction sequences
+ // like the following:
+ //
+ // LWI REG, FI1, 0
+ // ...
+ // SWI REG, FI2, 0
+ //
+ // As long as there are no defs of REG in the ... part, we can eliminate
+ // the SWI instruction because the value has already been stored to the
+ // stack by the caller. All we need to do is locate FI at the correct
+ // stack location according to the calling convensions.
+ //
+ // Additionally, if the SWI operation kills the def of REG then we don't
+ // need the LWI operation so we can erase it as well.
+ for (unsigned i = 0, e = LiveInFI.size(); i < e; ++i) {
+ for (MachineBasicBlock::iterator I=MIB; I != MIE; ++I) {
+ if (I->getOpcode() != MBlaze::LWI || I->getNumOperands() != 3 ||
+ !I->getOperand(1).isFI() || !I->getOperand(0).isReg() ||
+ I->getOperand(1).getIndex() != LiveInFI[i]) continue;
+
+ unsigned FIReg = I->getOperand(0).getReg();
+ MachineBasicBlock::iterator SI = I;
+ for (SI++; SI != MIE; ++SI) {
+ if (!SI->getOperand(0).isReg() ||
+ !SI->getOperand(1).isFI() ||
+ SI->getOpcode() != MBlaze::SWI) continue;
+
+ int FI = SI->getOperand(1).getIndex();
+ if (SI->getOperand(0).getReg() != FIReg ||
+ MFI->isFixedObjectIndex(FI) ||
+ MFI->getObjectSize(FI) != 4) continue;
+
+ if (SI->getOperand(0).isDef()) break;
+
+ if (SI->getOperand(0).isKill()) {
+ DEBUG(dbgs() << "LWI for FI#" << I->getOperand(1).getIndex()
+ << " removed\n");
+ EraseInstr.push_back(I);
+ }
+
+ EraseInstr.push_back(SI);
+ DEBUG(dbgs() << "SWI for FI#" << FI << " removed\n");
+
+ FrameRelocate.push_back(std::make_pair(FI,StackOffset));
+ DEBUG(dbgs() << "FI#" << FI << " relocated to " << StackOffset << "\n");
+
+ StackOffset -= 4;
+ StackAdjust += 4;
+ break;
+ }
+ }
+ }
+
+ // In this loop we are searching for frame indexes that corrospond to
+ // incoming arguments that are in registers. We look for instruction
+ // sequences like the following:
+ //
+ // ... SWI REG, FI, 0
+ //
+ // As long as the ... part does not define REG and if REG is an incoming
+ // parameter register then we know that, according to ABI convensions, the
+ // caller has allocated stack space for it already. Instead of allocating
+ // stack space on our frame, we record the correct location in the callers
+ // frame.
+ for (MachineRegisterInfo::livein_iterator LI = LII; LI != LIE; ++LI) {
+ for (MachineBasicBlock::iterator I=MIB; I != MIE; ++I) {
+ if (I->definesRegister(LI->first))
+ break;
+
+ if (I->getOpcode() != MBlaze::SWI || I->getNumOperands() != 3 ||
+ !I->getOperand(1).isFI() || !I->getOperand(0).isReg() ||
+ I->getOperand(1).getIndex() < 0) continue;
+
+ if (I->getOperand(0).getReg() == LI->first) {
+ int FI = I->getOperand(1).getIndex();
+ MBlazeFI->recordLiveIn(FI);
+
+ int FILoc = 0;
+ switch (LI->first) {
+ default: llvm_unreachable("invalid incoming parameter!");
+ case MBlaze::R5: FILoc = -4; break;
+ case MBlaze::R6: FILoc = -8; break;
+ case MBlaze::R7: FILoc = -12; break;
+ case MBlaze::R8: FILoc = -16; break;
+ case MBlaze::R9: FILoc = -20; break;
+ case MBlaze::R10: FILoc = -24; break;
+ }
+
+ StackAdjust += 4;
+ FrameRelocate.push_back(std::make_pair(FI,FILoc));
+ DEBUG(dbgs() << "FI#" << FI << " relocated to " << FILoc << "\n");
+ break;
+ }
+ }
+ }
+
+ // Go ahead and erase all of the instructions that we determined were
+ // no longer needed.
+ for (int i = 0, e = EraseInstr.size(); i < e; ++i)
+ MBB->erase(EraseInstr[i]);
+
+ // Replace all of the frame indexes that we have relocated with new
+ // fixed object frame indexes.
+ replaceFrameIndexes(MF, FrameRelocate);
+}
+
+static void interruptFrameLayout(MachineFunction &MF) {
+ const Function *F = MF.getFunction();
+ llvm::CallingConv::ID CallConv = F->getCallingConv();
+
+ // If this function is not using either the interrupt_handler
+ // calling convention or the save_volatiles calling convention
+ // then we don't need to do any additional frame layout.
+ if (CallConv != llvm::CallingConv::MBLAZE_INTR &&
+ CallConv != llvm::CallingConv::MBLAZE_SVOL)
+ return;
+
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ const MachineRegisterInfo &MRI = MF.getRegInfo();
+ const MBlazeInstrInfo &TII =
+ *static_cast<const MBlazeInstrInfo*>(MF.getTarget().getInstrInfo());
+
+ // Determine if the calling convention is the interrupt_handler
+ // calling convention. Some pieces of the prologue and epilogue
+ // only need to be emitted if we are lowering and interrupt handler.
+ bool isIntr = CallConv == llvm::CallingConv::MBLAZE_INTR;
+
+ // Determine where to put prologue and epilogue additions
+ MachineBasicBlock &MENT = MF.front();
+ MachineBasicBlock &MEXT = MF.back();
+
+ MachineBasicBlock::iterator MENTI = MENT.begin();
+ MachineBasicBlock::iterator MEXTI = prior(MEXT.end());
+
+ DebugLoc ENTDL = MENTI != MENT.end() ? MENTI->getDebugLoc() : DebugLoc();
+ DebugLoc EXTDL = MEXTI != MEXT.end() ? MEXTI->getDebugLoc() : DebugLoc();
+
+ // Store the frame indexes generated during prologue additions for use
+ // when we are generating the epilogue additions.
+ SmallVector<int, 10> VFI;
+
+ // Build the prologue SWI for R3 - R12 if needed. Note that R11 must
+ // always have a SWI because it is used when processing RMSR.
+ for (unsigned r = MBlaze::R3; r <= MBlaze::R12; ++r) {
+ if (!MRI.isPhysRegUsed(r) && !(isIntr && r == MBlaze::R11)) continue;
+
+ int FI = MFI->CreateStackObject(4,4,false,false);
+ VFI.push_back(FI);
+
+ BuildMI(MENT, MENTI, ENTDL, TII.get(MBlaze::SWI), r)
+ .addFrameIndex(FI).addImm(0);
+ }
+
+ // Build the prologue SWI for R17, R18
+ int R17FI = MFI->CreateStackObject(4,4,false,false);
+ int R18FI = MFI->CreateStackObject(4,4,false,false);
+
+ BuildMI(MENT, MENTI, ENTDL, TII.get(MBlaze::SWI), MBlaze::R17)
+ .addFrameIndex(R17FI).addImm(0);
+
+ BuildMI(MENT, MENTI, ENTDL, TII.get(MBlaze::SWI), MBlaze::R18)
+ .addFrameIndex(R18FI).addImm(0);
+
+ // Buid the prologue SWI and the epilogue LWI for RMSR if needed
+ if (isIntr) {
+ int MSRFI = MFI->CreateStackObject(4,4,false,false);
+ BuildMI(MENT, MENTI, ENTDL, TII.get(MBlaze::MFS), MBlaze::R11)
+ .addReg(MBlaze::RMSR);
+ BuildMI(MENT, MENTI, ENTDL, TII.get(MBlaze::SWI), MBlaze::R11)
+ .addFrameIndex(MSRFI).addImm(0);
+
+ BuildMI(MEXT, MEXTI, EXTDL, TII.get(MBlaze::LWI), MBlaze::R11)
+ .addFrameIndex(MSRFI).addImm(0);
+ BuildMI(MEXT, MEXTI, EXTDL, TII.get(MBlaze::MTS), MBlaze::RMSR)
+ .addReg(MBlaze::R11);
+ }
- // See the description at MicroBlazeMachineFunction.h
- int TopCPUSavedRegOff = -1;
+ // Build the epilogue LWI for R17, R18
+ BuildMI(MEXT, MEXTI, EXTDL, TII.get(MBlaze::LWI), MBlaze::R18)
+ .addFrameIndex(R18FI).addImm(0);
+
+ BuildMI(MEXT, MEXTI, EXTDL, TII.get(MBlaze::LWI), MBlaze::R17)
+ .addFrameIndex(R17FI).addImm(0);
+
+ // Build the epilogue LWI for R3 - R12 if needed
+ for (unsigned r = MBlaze::R12, i = VFI.size(); r >= MBlaze::R3; --r) {
+ if (!MRI.isPhysRegUsed(r)) continue;
+ BuildMI(MEXT, MEXTI, EXTDL, TII.get(MBlaze::LWI), r)
+ .addFrameIndex(VFI[--i]).addImm(0);
+ }
+}
- // Adjust CPU Callee Saved Registers Area. Registers RA and FP must
- // be saved in this CPU Area there is the need. This whole Area must
- // be aligned to the default Stack Alignment requirements.
- unsigned StackOffset = MFI->getStackSize();
- unsigned RegSize = 4;
+static void determineFrameLayout(MachineFunction &MF) {
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ MBlazeFunctionInfo *MBlazeFI = MF.getInfo<MBlazeFunctionInfo>();
// Replace the dummy '0' SPOffset by the negative offsets, as explained on
// LowerFORMAL_ARGUMENTS. Leaving '0' for while is necessary to avoid
MBlazeFI->adjustLoadArgsFI(MFI);
MBlazeFI->adjustStoreVarArgsFI(MFI);
- if (RegInfo->hasFP(MF)) {
- MFI->setObjectOffset(MFI->CreateStackObject(RegSize, RegSize, true),
- StackOffset);
- MBlazeFI->setFPStackOffset(StackOffset);
- TopCPUSavedRegOff = StackOffset;
- StackOffset += RegSize;
- }
+ // Get the number of bytes to allocate from the FrameInfo
+ unsigned FrameSize = MFI->getStackSize();
+ DEBUG(dbgs() << "Original Frame Size: " << FrameSize << "\n" );
- if (MFI->adjustsStack()) {
- MBlazeFI->setRAStackOffset(0);
- MFI->setObjectOffset(MFI->CreateStackObject(RegSize, RegSize, true),
- StackOffset);
- TopCPUSavedRegOff = StackOffset;
- StackOffset += RegSize;
- }
+ // Get the alignments provided by the target, and the maximum alignment
+ // (if any) of the fixed frame objects.
+ // unsigned MaxAlign = MFI->getMaxAlignment();
+ unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
+ unsigned AlignMask = TargetAlign - 1;
- // Update frame info
- MFI->setStackSize(StackOffset);
+ // Make sure the frame is aligned.
+ FrameSize = (FrameSize + AlignMask) & ~AlignMask;
+ MFI->setStackSize(FrameSize);
+ DEBUG(dbgs() << "Aligned Frame Size: " << FrameSize << "\n" );
+}
- // 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)
- MBlazeFI->setCPUTopSavedRegOff(TopCPUSavedRegOff-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 MBlazeFrameInfo::hasFP(const MachineFunction &MF) const {
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+ return DisableFramePointerElim(MF) || MFI->hasVarSizedObjects();
}
void MBlazeFrameInfo::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front();
MachineFrameInfo *MFI = MF.getFrameInfo();
- const MBlazeRegisterInfo *RegInfo =
- static_cast<const MBlazeRegisterInfo*>(MF.getTarget().getRegisterInfo());
const MBlazeInstrInfo &TII =
*static_cast<const MBlazeInstrInfo*>(MF.getTarget().getInstrInfo());
MBlazeFunctionInfo *MBlazeFI = MF.getInfo<MBlazeFunctionInfo>();
MachineBasicBlock::iterator MBBI = MBB.begin();
DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
- // Get the right frame order for MBlaze.
- adjustMBlazeStackFrame(MF);
+ llvm::CallingConv::ID CallConv = MF.getFunction()->getCallingConv();
+ bool requiresRA = CallConv == llvm::CallingConv::MBLAZE_INTR;
+
+ // Determine the correct frame layout
+ determineFrameLayout(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;
- if (StackSize < 28 && MFI->adjustsStack()) StackSize = 28;
+ if (StackSize == 0 && !MFI->adjustsStack() && !requiresRA) return;
int FPOffset = MBlazeFI->getFPStackOffset();
int RAOffset = MBlazeFI->getRAStackOffset();
// Adjust stack : addi R1, R1, -imm
- BuildMI(MBB, MBBI, DL, TII.get(MBlaze::ADDI), MBlaze::R1)
+ BuildMI(MBB, MBBI, DL, TII.get(MBlaze::ADDIK), MBlaze::R1)
.addReg(MBlaze::R1).addImm(-StackSize);
- // Save the return address only if the function isnt a leaf one.
// swi R15, R1, stack_loc
- if (MFI->adjustsStack()) {
+ if (MFI->adjustsStack() || requiresRA) {
BuildMI(MBB, MBBI, DL, TII.get(MBlaze::SWI))
.addReg(MBlaze::R15).addReg(MBlaze::R1).addImm(RAOffset);
}
- // if framepointer enabled, save it and set it
- // to point to the stack pointer
- if (RegInfo->hasFP(MF)) {
+ if (hasFP(MF)) {
// swi R19, R1, stack_loc
BuildMI(MBB, MBBI, DL, TII.get(MBlaze::SWI))
.addReg(MBlaze::R19).addReg(MBlaze::R1).addImm(FPOffset);
MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator MBBI = prior(MBB.end());
MachineFrameInfo *MFI = MF.getFrameInfo();
- MBlazeFunctionInfo *MBlazeFI = MF.getInfo<MBlazeFunctionInfo>();
- const MBlazeRegisterInfo *RegInfo =
- static_cast<const MBlazeRegisterInfo*>(MF.getTarget().getRegisterInfo());
+ MBlazeFunctionInfo *MBlazeFI = MF.getInfo<MBlazeFunctionInfo>();
const MBlazeInstrInfo &TII =
*static_cast<const MBlazeInstrInfo*>(MF.getTarget().getInstrInfo());
DebugLoc dl = MBBI->getDebugLoc();
+ llvm::CallingConv::ID CallConv = MF.getFunction()->getCallingConv();
+ bool requiresRA = CallConv == llvm::CallingConv::MBLAZE_INTR;
+
// Get the FI's where RA and FP are saved.
int FPOffset = MBlazeFI->getFPStackOffset();
int RAOffset = MBlazeFI->getRAStackOffset();
- // if framepointer enabled, restore it and restore the
- // stack pointer
- if (RegInfo->hasFP(MF)) {
+ if (hasFP(MF)) {
// add R1, R19, R0
BuildMI(MBB, MBBI, dl, TII.get(MBlaze::ADD), MBlaze::R1)
.addReg(MBlaze::R19).addReg(MBlaze::R0);
.addReg(MBlaze::R1).addImm(FPOffset);
}
- // Restore the return address only if the function isnt a leaf one.
// lwi R15, R1, stack_loc
- if (MFI->adjustsStack()) {
+ if (MFI->adjustsStack() || requiresRA) {
BuildMI(MBB, MBBI, dl, TII.get(MBlaze::LWI), MBlaze::R15)
.addReg(MBlaze::R1).addImm(RAOffset);
}
// Get the number of bytes from FrameInfo
int StackSize = (int) MFI->getStackSize();
- if (StackSize < 28 && MFI->adjustsStack()) StackSize = 28;
- // adjust stack.
// addi R1, R1, imm
if (StackSize) {
- BuildMI(MBB, MBBI, dl, TII.get(MBlaze::ADDI), MBlaze::R1)
+ BuildMI(MBB, MBBI, dl, TII.get(MBlaze::ADDIK), MBlaze::R1)
.addReg(MBlaze::R1).addImm(StackSize);
}
}
+
+void MBlazeFrameInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF, RegScavenger *RS)
+ const {
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ MBlazeFunctionInfo *MBlazeFI = MF.getInfo<MBlazeFunctionInfo>();
+ llvm::CallingConv::ID CallConv = MF.getFunction()->getCallingConv();
+ bool requiresRA = CallConv == llvm::CallingConv::MBLAZE_INTR;
+
+ if (MFI->adjustsStack() || requiresRA) {
+ MBlazeFI->setRAStackOffset(0);
+ MFI->CreateFixedObject(4,0,true);
+ }
+
+ if (hasFP(MF)) {
+ MBlazeFI->setFPStackOffset(4);
+ MFI->CreateFixedObject(4,4,true);
+ }
+
+ interruptFrameLayout(MF);
+ analyzeFrameIndexes(MF);
+}
projects / oota-llvm.git / blobdiff