X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTarget%2FMips%2FMipsFrameLowering.cpp;h=eb9d49fefb2fe829b8ac1bd4f51a62b2aca0a29c;hb=cd7319dc5f91ac81ab9d8505f34937e91bfcf65d;hp=c186b5d4cc321568d24a619e19c543e12c80abac;hpb=bb481f882093fb738d2bb15610c79364bada5496;p=oota-llvm.git diff --git a/lib/Target/Mips/MipsFrameLowering.cpp b/lib/Target/Mips/MipsFrameLowering.cpp index c186b5d4cc3..eb9d49fefb2 100644 --- a/lib/Target/Mips/MipsFrameLowering.cpp +++ b/lib/Target/Mips/MipsFrameLowering.cpp @@ -11,20 +11,21 @@ // //===----------------------------------------------------------------------===// -#include "MipsAnalyzeImmediate.h" #include "MipsFrameLowering.h" +#include "MCTargetDesc/MipsBaseInfo.h" +#include "MipsAnalyzeImmediate.h" #include "MipsInstrInfo.h" #include "MipsMachineFunction.h" -#include "MCTargetDesc/MipsBaseInfo.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/IR/DataLayout.h" +#include "llvm/IR/Function.h" #include "llvm/Support/CommandLine.h" +#include "llvm/Target/TargetOptions.h" using namespace llvm; @@ -81,6 +82,14 @@ 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. @@ -90,239 +99,36 @@ bool MipsFrameLowering::hasFP(const MachineFunction &MF) const { MFI->hasVarSizedObjects() || MFI->isFrameAddressTaken(); } -bool MipsFrameLowering::targetHandlesStackFrameRounding() const { - return true; -} - -// Build an instruction sequence to load an immediate that is too large to fit -// in 16-bit and add the result to Reg. -static void expandLargeImm(unsigned Reg, int64_t Imm, bool IsN64, - const MipsInstrInfo &TII, MachineBasicBlock& MBB, - MachineBasicBlock::iterator II, DebugLoc DL) { - unsigned LUi = IsN64 ? Mips::LUi64 : Mips::LUi; - unsigned ADDu = IsN64 ? Mips::DADDu : Mips::ADDu; - unsigned ZEROReg = IsN64 ? Mips::ZERO_64 : Mips::ZERO; - unsigned ATReg = IsN64 ? Mips::AT_64 : Mips::AT; - MipsAnalyzeImmediate AnalyzeImm; - const MipsAnalyzeImmediate::InstSeq &Seq = - AnalyzeImm.Analyze(Imm, IsN64 ? 64 : 32, false /* LastInstrIsADDiu */); - MipsAnalyzeImmediate::InstSeq::const_iterator Inst = Seq.begin(); - - // FIXME: change this when mips goes MC". - BuildMI(MBB, II, DL, TII.get(Mips::NOAT)); - - // The first instruction can be a LUi, which is different from other - // instructions (ADDiu, ORI and SLL) in that it does not have a register - // operand. - if (Inst->Opc == LUi) - BuildMI(MBB, II, DL, TII.get(LUi), ATReg) - .addImm(SignExtend64<16>(Inst->ImmOpnd)); - else - BuildMI(MBB, II, DL, TII.get(Inst->Opc), ATReg).addReg(ZEROReg) - .addImm(SignExtend64<16>(Inst->ImmOpnd)); - - // Build the remaining instructions in Seq. - for (++Inst; Inst != Seq.end(); ++Inst) - BuildMI(MBB, II, DL, TII.get(Inst->Opc), ATReg).addReg(ATReg) - .addImm(SignExtend64<16>(Inst->ImmOpnd)); - - BuildMI(MBB, II, DL, TII.get(ADDu), Reg).addReg(Reg).addReg(ATReg); - BuildMI(MBB, II, DL, TII.get(Mips::ATMACRO)); -} - -void MipsFrameLowering::emitPrologue(MachineFunction &MF) const { - MachineBasicBlock &MBB = MF.front(); - MachineFrameInfo *MFI = MF.getFrameInfo(); - MipsFunctionInfo *MipsFI = MF.getInfo(); - const MipsRegisterInfo *RegInfo = - static_cast(MF.getTarget().getRegisterInfo()); - const MipsInstrInfo &TII = - *static_cast(MF.getTarget().getInstrInfo()); - MachineBasicBlock::iterator MBBI = MBB.begin(); - DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc(); - bool isPIC = (MF.getTarget().getRelocationModel() == Reloc::PIC_); - unsigned SP = STI.isABI_N64() ? Mips::SP_64 : Mips::SP; - unsigned FP = STI.isABI_N64() ? Mips::FP_64 : Mips::FP; - unsigned ZERO = STI.isABI_N64() ? Mips::ZERO_64 : Mips::ZERO; - unsigned ADDu = STI.isABI_N64() ? Mips::DADDu : Mips::ADDu; - unsigned ADDiu = STI.isABI_N64() ? Mips::DADDiu : Mips::ADDiu; - - // First, compute final stack size. - unsigned RegSize = STI.isGP32bit() ? 4 : 8; - unsigned StackAlign = getStackAlignment(); - unsigned LocalVarAreaOffset = MipsFI->needGPSaveRestore() ? - (MFI->getObjectOffset(MipsFI->getGPFI()) + RegSize) : - MipsFI->getMaxCallFrameSize(); - uint64_t StackSize = RoundUpToAlignment(LocalVarAreaOffset, StackAlign) + - RoundUpToAlignment(MFI->getStackSize(), StackAlign); - - // Update stack size - MFI->setStackSize(StackSize); - - BuildMI(MBB, MBBI, dl, TII.get(Mips::NOREORDER)); - BuildMI(MBB, MBBI, dl, TII.get(Mips::NOMACRO)); - - // Emit instructions that set the global base register if the target ABI is - // O32. - if (isPIC && MipsFI->globalBaseRegSet() && STI.isABI_O32()) { - if (MipsFI->globalBaseRegFixed()) - BuildMI(MBB, llvm::prior(MBBI), dl, TII.get(Mips::CPLOAD)) - .addReg(RegInfo->getPICCallReg()); - else - // See MipsInstrInfo.td for explanation. - BuildMI(MBB, MBBI, dl, TII.get(Mips:: SETGP01), Mips::V0); - } - - // No need to allocate space on the stack. - if (StackSize == 0 && !MFI->adjustsStack()) return; - - MachineModuleInfo &MMI = MF.getMMI(); - std::vector &Moves = MMI.getFrameMoves(); - MachineLocation DstML, SrcML; - - // Adjust stack. - if (isInt<16>(-StackSize)) // addi sp, sp, (-stacksize) - BuildMI(MBB, MBBI, dl, TII.get(ADDiu), SP).addReg(SP).addImm(-StackSize); - else // Expand immediate that doesn't fit in 16-bit. - expandLargeImm(SP, -StackSize, STI.isABI_N64(), TII, MBB, MBBI, dl); - - // emit ".cfi_def_cfa_offset StackSize" - MCSymbol *AdjustSPLabel = MMI.getContext().CreateTempSymbol(); - BuildMI(MBB, MBBI, dl, - TII.get(TargetOpcode::PROLOG_LABEL)).addSym(AdjustSPLabel); - DstML = MachineLocation(MachineLocation::VirtualFP); - SrcML = MachineLocation(MachineLocation::VirtualFP, -StackSize); - Moves.push_back(MachineMove(AdjustSPLabel, DstML, SrcML)); - - const std::vector &CSI = MFI->getCalleeSavedInfo(); - - if (CSI.size()) { - // Find the instruction past the last instruction that saves a callee-saved - // register to the stack. - for (unsigned i = 0; i < CSI.size(); ++i) - ++MBBI; - - // Iterate over list of callee-saved registers and emit .cfi_offset - // directives. - MCSymbol *CSLabel = MMI.getContext().CreateTempSymbol(); - BuildMI(MBB, MBBI, dl, - TII.get(TargetOpcode::PROLOG_LABEL)).addSym(CSLabel); - - for (std::vector::const_iterator I = CSI.begin(), - E = CSI.end(); I != E; ++I) { - int64_t Offset = MFI->getObjectOffset(I->getFrameIdx()); - unsigned Reg = I->getReg(); - - // If Reg is a double precision register, emit two cfa_offsets, - // one for each of the paired single precision registers. - if (Mips::AFGR64RegisterClass->contains(Reg)) { - const unsigned *SubRegs = RegInfo->getSubRegisters(Reg); - MachineLocation DstML0(MachineLocation::VirtualFP, Offset); - MachineLocation DstML1(MachineLocation::VirtualFP, Offset + 4); - MachineLocation SrcML0(*SubRegs); - MachineLocation SrcML1(*(SubRegs + 1)); - - if (!STI.isLittle()) - std::swap(SrcML0, SrcML1); - - Moves.push_back(MachineMove(CSLabel, DstML0, SrcML0)); - Moves.push_back(MachineMove(CSLabel, DstML1, SrcML1)); - } - else { - // Reg is either in CPURegs or FGR32. - DstML = MachineLocation(MachineLocation::VirtualFP, Offset); - SrcML = MachineLocation(Reg); - Moves.push_back(MachineMove(CSLabel, DstML, SrcML)); - } - } - } - - // if framepointer enabled, set it to point to the stack pointer. - if (hasFP(MF)) { - // Insert instruction "move $fp, $sp" at this location. - BuildMI(MBB, MBBI, dl, TII.get(ADDu), FP).addReg(SP).addReg(ZERO); - - // emit ".cfi_def_cfa_register $fp" - MCSymbol *SetFPLabel = MMI.getContext().CreateTempSymbol(); - BuildMI(MBB, MBBI, dl, - TII.get(TargetOpcode::PROLOG_LABEL)).addSym(SetFPLabel); - DstML = MachineLocation(FP); - SrcML = MachineLocation(MachineLocation::VirtualFP); - Moves.push_back(MachineMove(SetFPLabel, DstML, SrcML)); - } - - // Restore GP from the saved stack location - if (MipsFI->needGPSaveRestore()) { - unsigned Offset = MFI->getObjectOffset(MipsFI->getGPFI()); - BuildMI(MBB, MBBI, dl, TII.get(Mips::CPRESTORE)).addImm(Offset); - - if (Offset >= 0x8000) { - BuildMI(MBB, llvm::prior(MBBI), dl, TII.get(Mips::MACRO)); - BuildMI(MBB, MBBI, dl, TII.get(Mips::NOMACRO)); - } - } -} - -void MipsFrameLowering::emitEpilogue(MachineFunction &MF, - MachineBasicBlock &MBB) const { - MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr(); - MachineFrameInfo *MFI = MF.getFrameInfo(); - const MipsInstrInfo &TII = - *static_cast(MF.getTarget().getInstrInfo()); - DebugLoc dl = MBBI->getDebugLoc(); - unsigned SP = STI.isABI_N64() ? Mips::SP_64 : Mips::SP; - unsigned FP = STI.isABI_N64() ? Mips::FP_64 : Mips::FP; - unsigned ZERO = STI.isABI_N64() ? Mips::ZERO_64 : Mips::ZERO; - unsigned ADDu = STI.isABI_N64() ? Mips::DADDu : Mips::ADDu; - unsigned ADDiu = STI.isABI_N64() ? Mips::DADDiu : Mips::ADDiu; +uint64_t MipsFrameLowering::estimateStackSize(const MachineFunction &MF) const { + const MachineFrameInfo *MFI = MF.getFrameInfo(); + const TargetRegisterInfo &TRI = *MF.getTarget().getRegisterInfo(); - // if framepointer enabled, restore the stack pointer. - if (hasFP(MF)) { - // Find the first instruction that restores a callee-saved register. - MachineBasicBlock::iterator I = MBBI; + int64_t Offset = 0; - for (unsigned i = 0; i < MFI->getCalleeSavedInfo().size(); ++i) - --I; + // Iterate over fixed sized objects. + for (int I = MFI->getObjectIndexBegin(); I != 0; ++I) + Offset = std::max(Offset, -MFI->getObjectOffset(I)); - // Insert instruction "move $sp, $fp" at this location. - BuildMI(MBB, I, dl, TII.get(ADDu), SP).addReg(FP).addReg(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); } - // Get the number of bytes from FrameInfo - uint64_t StackSize = MFI->getStackSize(); - - if (!StackSize) - return; + unsigned MaxAlign = MFI->getMaxAlignment(); - // Adjust stack. - if (isInt<16>(StackSize)) // addi sp, sp, (-stacksize) - BuildMI(MBB, MBBI, dl, TII.get(ADDiu), SP).addReg(SP).addImm(StackSize); - else // Expand immediate that doesn't fit in 16-bit. - expandLargeImm(SP, StackSize, STI.isABI_N64(), TII, MBB, MBBI, dl); -} + // Check that MaxAlign is not zero if there is a stack object that is not a + // callee-saved spill. + assert(!MFI->getObjectIndexEnd() || MaxAlign); -void MipsFrameLowering:: -processFunctionBeforeCalleeSavedScan(MachineFunction &MF, - RegScavenger *RS) const { - MachineRegisterInfo& MRI = MF.getRegInfo(); - unsigned FP = STI.isABI_N64() ? Mips::FP_64 : Mips::FP; + // Iterate over other objects. + for (unsigned I = 0, E = MFI->getObjectIndexEnd(); I != E; ++I) + Offset = RoundUpToAlignment(Offset + MFI->getObjectSize(I), MaxAlign); - // FIXME: remove this code if register allocator can correctly mark - // $fp and $ra used or unused. + // Call frame. + if (MFI->adjustsStack() && hasReservedCallFrame(MF)) + Offset = RoundUpToAlignment(Offset + MFI->getMaxCallFrameSize(), + std::max(MaxAlign, getStackAlignment())); - // Mark $fp and $ra as used or unused. - if (hasFP(MF)) - MRI.setPhysRegUsed(FP); - - // The register allocator might determine $ra is used after seeing - // instruction "jr $ra", but we do not want PrologEpilogInserter to insert - // instructions to save/restore $ra unless there is a function call. - // To correct this, $ra is explicitly marked unused if there is no - // function call. - if (MF.getFrameInfo()->hasCalls()) - MRI.setPhysRegUsed(Mips::RA); - else { - MRI.setPhysRegUnused(Mips::RA); - MRI.setPhysRegUnused(Mips::RA_64); - } + return RoundUpToAlignment(Offset, getStackAlignment()); }