diff options
Diffstat (limited to 'contrib/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp')
-rw-r--r-- | contrib/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp | 248 |
1 files changed, 155 insertions, 93 deletions
diff --git a/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp index 61b2c7e65842..debe88f3b1ee 100644 --- a/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp +++ b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp @@ -22,79 +22,76 @@ using namespace llvm; -void DwarfExpression::AddReg(int DwarfReg, const char *Comment) { +void DwarfExpression::addReg(int DwarfReg, const char *Comment) { assert(DwarfReg >= 0 && "invalid negative dwarf register number"); if (DwarfReg < 32) { - EmitOp(dwarf::DW_OP_reg0 + DwarfReg, Comment); + emitOp(dwarf::DW_OP_reg0 + DwarfReg, Comment); } else { - EmitOp(dwarf::DW_OP_regx, Comment); - EmitUnsigned(DwarfReg); + emitOp(dwarf::DW_OP_regx, Comment); + emitUnsigned(DwarfReg); } } -void DwarfExpression::AddRegIndirect(int DwarfReg, int Offset, bool Deref) { +void DwarfExpression::addBReg(int DwarfReg, int Offset) { assert(DwarfReg >= 0 && "invalid negative dwarf register number"); if (DwarfReg < 32) { - EmitOp(dwarf::DW_OP_breg0 + DwarfReg); + emitOp(dwarf::DW_OP_breg0 + DwarfReg); } else { - EmitOp(dwarf::DW_OP_bregx); - EmitUnsigned(DwarfReg); + emitOp(dwarf::DW_OP_bregx); + emitUnsigned(DwarfReg); } - EmitSigned(Offset); - if (Deref) - EmitOp(dwarf::DW_OP_deref); + emitSigned(Offset); } -void DwarfExpression::AddOpPiece(unsigned SizeInBits, unsigned OffsetInBits) { +void DwarfExpression::addFBReg(int Offset) { + emitOp(dwarf::DW_OP_fbreg); + emitSigned(Offset); +} + +void DwarfExpression::addOpPiece(unsigned SizeInBits, unsigned OffsetInBits) { if (!SizeInBits) return; const unsigned SizeOfByte = 8; if (OffsetInBits > 0 || SizeInBits % SizeOfByte) { - EmitOp(dwarf::DW_OP_bit_piece); - EmitUnsigned(SizeInBits); - EmitUnsigned(OffsetInBits); + emitOp(dwarf::DW_OP_bit_piece); + emitUnsigned(SizeInBits); + emitUnsigned(OffsetInBits); } else { - EmitOp(dwarf::DW_OP_piece); + emitOp(dwarf::DW_OP_piece); unsigned ByteSize = SizeInBits / SizeOfByte; - EmitUnsigned(ByteSize); + emitUnsigned(ByteSize); } this->OffsetInBits += SizeInBits; } -void DwarfExpression::AddShr(unsigned ShiftBy) { - EmitOp(dwarf::DW_OP_constu); - EmitUnsigned(ShiftBy); - EmitOp(dwarf::DW_OP_shr); +void DwarfExpression::addShr(unsigned ShiftBy) { + emitOp(dwarf::DW_OP_constu); + emitUnsigned(ShiftBy); + emitOp(dwarf::DW_OP_shr); } -bool DwarfExpression::AddMachineRegIndirect(const TargetRegisterInfo &TRI, - unsigned MachineReg, int Offset) { - if (isFrameRegister(TRI, MachineReg)) { - // If variable offset is based in frame register then use fbreg. - EmitOp(dwarf::DW_OP_fbreg); - EmitSigned(Offset); - return true; - } - - int DwarfReg = TRI.getDwarfRegNum(MachineReg, false); - if (DwarfReg < 0) - return false; - - AddRegIndirect(DwarfReg, Offset); - return true; +void DwarfExpression::addAnd(unsigned Mask) { + emitOp(dwarf::DW_OP_constu); + emitUnsigned(Mask); + emitOp(dwarf::DW_OP_and); } -bool DwarfExpression::AddMachineReg(const TargetRegisterInfo &TRI, +bool DwarfExpression::addMachineReg(const TargetRegisterInfo &TRI, unsigned MachineReg, unsigned MaxSize) { - if (!TRI.isPhysicalRegister(MachineReg)) + if (!TRI.isPhysicalRegister(MachineReg)) { + if (isFrameRegister(TRI, MachineReg)) { + DwarfRegs.push_back({-1, 0, nullptr}); + return true; + } return false; + } int Reg = TRI.getDwarfRegNum(MachineReg, false); // If this is a valid register number, emit it. if (Reg >= 0) { - AddReg(Reg); + DwarfRegs.push_back({Reg, 0, nullptr}); return true; } @@ -106,7 +103,7 @@ bool DwarfExpression::AddMachineReg(const TargetRegisterInfo &TRI, unsigned Idx = TRI.getSubRegIndex(*SR, MachineReg); unsigned Size = TRI.getSubRegIdxSize(Idx); unsigned RegOffset = TRI.getSubRegIdxOffset(Idx); - AddReg(Reg, "super-register"); + DwarfRegs.push_back({Reg, 0, "super-register"}); // Use a DW_OP_bit_piece to describe the sub-register. setSubRegisterPiece(Size, RegOffset); return true; @@ -136,72 +133,101 @@ bool DwarfExpression::AddMachineReg(const TargetRegisterInfo &TRI, // If this sub-register has a DWARF number and we haven't covered // its range, emit a DWARF piece for it. if (Reg >= 0 && Intersection.any()) { - AddReg(Reg, "sub-register"); + // Emit a piece for any gap in the coverage. + if (Offset > CurPos) + DwarfRegs.push_back({-1, Offset - CurPos, nullptr}); + DwarfRegs.push_back( + {Reg, std::min<unsigned>(Size, MaxSize - Offset), "sub-register"}); if (Offset >= MaxSize) break; - // Emit a piece for the any gap in the coverage. - if (Offset > CurPos) - AddOpPiece(Offset - CurPos); - AddOpPiece(std::min<unsigned>(Size, MaxSize - Offset)); - CurPos = Offset + Size; // Mark it as emitted. Coverage.set(Offset, Offset + Size); + CurPos = Offset + Size; } } return CurPos; } -void DwarfExpression::AddStackValue() { +void DwarfExpression::addStackValue() { if (DwarfVersion >= 4) - EmitOp(dwarf::DW_OP_stack_value); + emitOp(dwarf::DW_OP_stack_value); } -void DwarfExpression::AddSignedConstant(int64_t Value) { - EmitOp(dwarf::DW_OP_consts); - EmitSigned(Value); - AddStackValue(); +void DwarfExpression::addSignedConstant(int64_t Value) { + emitOp(dwarf::DW_OP_consts); + emitSigned(Value); + addStackValue(); } -void DwarfExpression::AddUnsignedConstant(uint64_t Value) { - EmitOp(dwarf::DW_OP_constu); - EmitUnsigned(Value); - AddStackValue(); +void DwarfExpression::addUnsignedConstant(uint64_t Value) { + emitOp(dwarf::DW_OP_constu); + emitUnsigned(Value); + addStackValue(); } -void DwarfExpression::AddUnsignedConstant(const APInt &Value) { +void DwarfExpression::addUnsignedConstant(const APInt &Value) { unsigned Size = Value.getBitWidth(); const uint64_t *Data = Value.getRawData(); // Chop it up into 64-bit pieces, because that's the maximum that - // AddUnsignedConstant takes. + // addUnsignedConstant takes. unsigned Offset = 0; while (Offset < Size) { - AddUnsignedConstant(*Data++); + addUnsignedConstant(*Data++); if (Offset == 0 && Size <= 64) break; - AddOpPiece(std::min(Size-Offset, 64u), Offset); + addOpPiece(std::min(Size-Offset, 64u), Offset); Offset += 64; } } -bool DwarfExpression::AddMachineRegExpression(const TargetRegisterInfo &TRI, +bool DwarfExpression::addMachineRegExpression(const TargetRegisterInfo &TRI, DIExpressionCursor &ExprCursor, unsigned MachineReg, unsigned FragmentOffsetInBits) { - if (!ExprCursor) - return AddMachineReg(TRI, MachineReg); + auto Fragment = ExprCursor.getFragmentInfo(); + if (!addMachineReg(TRI, MachineReg, Fragment ? Fragment->SizeInBits : ~1U)) + return false; - // Pattern-match combinations for which more efficient representations exist - // first. - bool ValidReg = false; + bool HasComplexExpression = false; auto Op = ExprCursor.peek(); + if (Op && Op->getOp() != dwarf::DW_OP_LLVM_fragment) + HasComplexExpression = true; + + // If the register can only be described by a complex expression (i.e., + // multiple subregisters) it doesn't safely compose with another complex + // expression. For example, it is not possible to apply a DW_OP_deref + // operation to multiple DW_OP_pieces. + if (HasComplexExpression && DwarfRegs.size() > 1) { + DwarfRegs.clear(); + return false; + } + + // Handle simple register locations. + if (!HasComplexExpression) { + for (auto &Reg : DwarfRegs) { + if (Reg.DwarfRegNo >= 0) + addReg(Reg.DwarfRegNo, Reg.Comment); + addOpPiece(Reg.Size); + } + DwarfRegs.clear(); + return true; + } + + assert(DwarfRegs.size() == 1); + auto Reg = DwarfRegs[0]; + bool FBReg = isFrameRegister(TRI, MachineReg); + assert(Reg.Size == 0 && "subregister has same size as superregister"); + + // Pattern-match combinations for which more efficient representations exist. switch (Op->getOp()) { default: { - auto Fragment = ExprCursor.getFragmentInfo(); - ValidReg = AddMachineReg(TRI, MachineReg, - Fragment ? Fragment->SizeInBits : ~1U); + if (FBReg) + addFBReg(0); + else + addReg(Reg.DwarfRegNo, 0); break; } case dwarf::DW_OP_plus: @@ -210,28 +236,42 @@ bool DwarfExpression::AddMachineRegExpression(const TargetRegisterInfo &TRI, // [DW_OP_reg,Offset,DW_OP_minus,DW_OP_deref] --> [DW_OP_breg,-Offset]. auto N = ExprCursor.peekNext(); if (N && N->getOp() == dwarf::DW_OP_deref) { - unsigned Offset = Op->getArg(0); - ValidReg = AddMachineRegIndirect( - TRI, MachineReg, Op->getOp() == dwarf::DW_OP_plus ? Offset : -Offset); + int Offset = Op->getArg(0); + int SignedOffset = (Op->getOp() == dwarf::DW_OP_plus) ? Offset : -Offset; + if (FBReg) + addFBReg(SignedOffset); + else + addBReg(Reg.DwarfRegNo, SignedOffset); + ExprCursor.consume(2); - } else - ValidReg = AddMachineReg(TRI, MachineReg); + break; + } + addReg(Reg.DwarfRegNo, 0); break; } case dwarf::DW_OP_deref: // [DW_OP_reg,DW_OP_deref] --> [DW_OP_breg]. - ValidReg = AddMachineRegIndirect(TRI, MachineReg); + if (FBReg) + addFBReg(0); + else + addBReg(Reg.DwarfRegNo, 0); ExprCursor.take(); break; } - - return ValidReg; + DwarfRegs.clear(); + return true; } -void DwarfExpression::AddExpression(DIExpressionCursor &&ExprCursor, +void DwarfExpression::addExpression(DIExpressionCursor &&ExprCursor, unsigned FragmentOffsetInBits) { while (ExprCursor) { auto Op = ExprCursor.take(); + + // If we need to mask out a subregister, do it now, unless the next + // operation would emit an OpPiece anyway. + if (SubRegisterSizeInBits && Op->getOp() != dwarf::DW_OP_LLVM_fragment) + maskSubRegister(); + switch (Op->getOp()) { case dwarf::DW_OP_LLVM_fragment: { unsigned SizeInBits = Op->getArg(1); @@ -241,39 +281,45 @@ void DwarfExpression::AddExpression(DIExpressionCursor &&ExprCursor, // location. assert(OffsetInBits >= FragmentOffset && "fragment offset not added?"); - // If \a AddMachineReg already emitted DW_OP_piece operations to represent + // If \a addMachineReg already emitted DW_OP_piece operations to represent // a super-register by splicing together sub-registers, subtract the size // of the pieces that was already emitted. SizeInBits -= OffsetInBits - FragmentOffset; - // If \a AddMachineReg requested a DW_OP_bit_piece to stencil out a + // If \a addMachineReg requested a DW_OP_bit_piece to stencil out a // sub-register that is smaller than the current fragment's size, use it. if (SubRegisterSizeInBits) SizeInBits = std::min<unsigned>(SizeInBits, SubRegisterSizeInBits); - AddOpPiece(SizeInBits, SubRegisterOffsetInBits); + addOpPiece(SizeInBits, SubRegisterOffsetInBits); setSubRegisterPiece(0, 0); break; } case dwarf::DW_OP_plus: - EmitOp(dwarf::DW_OP_plus_uconst); - EmitUnsigned(Op->getArg(0)); + emitOp(dwarf::DW_OP_plus_uconst); + emitUnsigned(Op->getArg(0)); break; case dwarf::DW_OP_minus: // There is no OP_minus_uconst. - EmitOp(dwarf::DW_OP_constu); - EmitUnsigned(Op->getArg(0)); - EmitOp(dwarf::DW_OP_minus); + emitOp(dwarf::DW_OP_constu); + emitUnsigned(Op->getArg(0)); + emitOp(dwarf::DW_OP_minus); break; case dwarf::DW_OP_deref: - EmitOp(dwarf::DW_OP_deref); + emitOp(dwarf::DW_OP_deref); break; case dwarf::DW_OP_constu: - EmitOp(dwarf::DW_OP_constu); - EmitUnsigned(Op->getArg(0)); + emitOp(dwarf::DW_OP_constu); + emitUnsigned(Op->getArg(0)); break; case dwarf::DW_OP_stack_value: - AddStackValue(); + addStackValue(); + break; + case dwarf::DW_OP_swap: + emitOp(dwarf::DW_OP_swap); + break; + case dwarf::DW_OP_xderef: + emitOp(dwarf::DW_OP_xderef); break; default: llvm_unreachable("unhandled opcode found in expression"); @@ -281,9 +327,25 @@ void DwarfExpression::AddExpression(DIExpressionCursor &&ExprCursor, } } +/// add masking operations to stencil out a subregister. +void DwarfExpression::maskSubRegister() { + assert(SubRegisterSizeInBits && "no subregister was registered"); + if (SubRegisterOffsetInBits > 0) + addShr(SubRegisterOffsetInBits); + uint64_t Mask = (1ULL << (uint64_t)SubRegisterSizeInBits) - 1ULL; + addAnd(Mask); +} + + void DwarfExpression::finalize() { - if (SubRegisterSizeInBits) - AddOpPiece(SubRegisterSizeInBits, SubRegisterOffsetInBits); + assert(DwarfRegs.size() == 0 && "dwarf registers not emitted"); + // Emit any outstanding DW_OP_piece operations to mask out subregisters. + if (SubRegisterSizeInBits == 0) + return; + // Don't emit a DW_OP_piece for a subregister at offset 0. + if (SubRegisterOffsetInBits == 0) + return; + addOpPiece(SubRegisterSizeInBits, SubRegisterOffsetInBits); } void DwarfExpression::addFragmentOffset(const DIExpression *Expr) { @@ -294,6 +356,6 @@ void DwarfExpression::addFragmentOffset(const DIExpression *Expr) { assert(FragmentOffset >= OffsetInBits && "overlapping or duplicate fragments"); if (FragmentOffset > OffsetInBits) - AddOpPiece(FragmentOffset - OffsetInBits); + addOpPiece(FragmentOffset - OffsetInBits); OffsetInBits = FragmentOffset; } |